xref: /qemu/hw/vfio/pci.c (revision 226419d6)
1 /*
2  * vfio based device assignment support
3  *
4  * Copyright Red Hat, Inc. 2012
5  *
6  * Authors:
7  *  Alex Williamson <alex.williamson@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2.  See
10  * the COPYING file in the top-level directory.
11  *
12  * Based on qemu-kvm device-assignment:
13  *  Adapted for KVM by Qumranet.
14  *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
15  *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
16  *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
17  *  Copyright (C) 2008, Red Hat, Amit Shah (amit.shah@redhat.com)
18  *  Copyright (C) 2008, IBM, Muli Ben-Yehuda (muli@il.ibm.com)
19  */
20 
21 #include "qemu/osdep.h"
22 #include <linux/vfio.h>
23 #include <sys/ioctl.h>
24 #include <sys/mman.h>
25 
26 #include "hw/pci/msi.h"
27 #include "hw/pci/msix.h"
28 #include "hw/pci/pci_bridge.h"
29 #include "qemu/error-report.h"
30 #include "qemu/range.h"
31 #include "sysemu/kvm.h"
32 #include "sysemu/sysemu.h"
33 #include "pci.h"
34 #include "trace.h"
35 
36 #define MSIX_CAP_LENGTH 12
37 
38 static void vfio_disable_interrupts(VFIOPCIDevice *vdev);
39 static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled);
40 
41 /*
42  * Disabling BAR mmaping can be slow, but toggling it around INTx can
43  * also be a huge overhead.  We try to get the best of both worlds by
44  * waiting until an interrupt to disable mmaps (subsequent transitions
45  * to the same state are effectively no overhead).  If the interrupt has
46  * been serviced and the time gap is long enough, we re-enable mmaps for
47  * performance.  This works well for things like graphics cards, which
48  * may not use their interrupt at all and are penalized to an unusable
49  * level by read/write BAR traps.  Other devices, like NICs, have more
50  * regular interrupts and see much better latency by staying in non-mmap
51  * mode.  We therefore set the default mmap_timeout such that a ping
52  * is just enough to keep the mmap disabled.  Users can experiment with
53  * other options with the x-intx-mmap-timeout-ms parameter (a value of
54  * zero disables the timer).
55  */
56 static void vfio_intx_mmap_enable(void *opaque)
57 {
58     VFIOPCIDevice *vdev = opaque;
59 
60     if (vdev->intx.pending) {
61         timer_mod(vdev->intx.mmap_timer,
62                        qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vdev->intx.mmap_timeout);
63         return;
64     }
65 
66     vfio_mmap_set_enabled(vdev, true);
67 }
68 
69 static void vfio_intx_interrupt(void *opaque)
70 {
71     VFIOPCIDevice *vdev = opaque;
72 
73     if (!event_notifier_test_and_clear(&vdev->intx.interrupt)) {
74         return;
75     }
76 
77     trace_vfio_intx_interrupt(vdev->vbasedev.name, 'A' + vdev->intx.pin);
78 
79     vdev->intx.pending = true;
80     pci_irq_assert(&vdev->pdev);
81     vfio_mmap_set_enabled(vdev, false);
82     if (vdev->intx.mmap_timeout) {
83         timer_mod(vdev->intx.mmap_timer,
84                        qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vdev->intx.mmap_timeout);
85     }
86 }
87 
88 static void vfio_intx_eoi(VFIODevice *vbasedev)
89 {
90     VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
91 
92     if (!vdev->intx.pending) {
93         return;
94     }
95 
96     trace_vfio_intx_eoi(vbasedev->name);
97 
98     vdev->intx.pending = false;
99     pci_irq_deassert(&vdev->pdev);
100     vfio_unmask_single_irqindex(vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
101 }
102 
103 static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev)
104 {
105 #ifdef CONFIG_KVM
106     struct kvm_irqfd irqfd = {
107         .fd = event_notifier_get_fd(&vdev->intx.interrupt),
108         .gsi = vdev->intx.route.irq,
109         .flags = KVM_IRQFD_FLAG_RESAMPLE,
110     };
111     struct vfio_irq_set *irq_set;
112     int ret, argsz;
113     int32_t *pfd;
114 
115     if (vdev->no_kvm_intx || !kvm_irqfds_enabled() ||
116         vdev->intx.route.mode != PCI_INTX_ENABLED ||
117         !kvm_resamplefds_enabled()) {
118         return;
119     }
120 
121     /* Get to a known interrupt state */
122     qemu_set_fd_handler(irqfd.fd, NULL, NULL, vdev);
123     vfio_mask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
124     vdev->intx.pending = false;
125     pci_irq_deassert(&vdev->pdev);
126 
127     /* Get an eventfd for resample/unmask */
128     if (event_notifier_init(&vdev->intx.unmask, 0)) {
129         error_report("vfio: Error: event_notifier_init failed eoi");
130         goto fail;
131     }
132 
133     /* KVM triggers it, VFIO listens for it */
134     irqfd.resamplefd = event_notifier_get_fd(&vdev->intx.unmask);
135 
136     if (kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd)) {
137         error_report("vfio: Error: Failed to setup resample irqfd: %m");
138         goto fail_irqfd;
139     }
140 
141     argsz = sizeof(*irq_set) + sizeof(*pfd);
142 
143     irq_set = g_malloc0(argsz);
144     irq_set->argsz = argsz;
145     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_UNMASK;
146     irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
147     irq_set->start = 0;
148     irq_set->count = 1;
149     pfd = (int32_t *)&irq_set->data;
150 
151     *pfd = irqfd.resamplefd;
152 
153     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
154     g_free(irq_set);
155     if (ret) {
156         error_report("vfio: Error: Failed to setup INTx unmask fd: %m");
157         goto fail_vfio;
158     }
159 
160     /* Let'em rip */
161     vfio_unmask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
162 
163     vdev->intx.kvm_accel = true;
164 
165     trace_vfio_intx_enable_kvm(vdev->vbasedev.name);
166 
167     return;
168 
169 fail_vfio:
170     irqfd.flags = KVM_IRQFD_FLAG_DEASSIGN;
171     kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd);
172 fail_irqfd:
173     event_notifier_cleanup(&vdev->intx.unmask);
174 fail:
175     qemu_set_fd_handler(irqfd.fd, vfio_intx_interrupt, NULL, vdev);
176     vfio_unmask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
177 #endif
178 }
179 
180 static void vfio_intx_disable_kvm(VFIOPCIDevice *vdev)
181 {
182 #ifdef CONFIG_KVM
183     struct kvm_irqfd irqfd = {
184         .fd = event_notifier_get_fd(&vdev->intx.interrupt),
185         .gsi = vdev->intx.route.irq,
186         .flags = KVM_IRQFD_FLAG_DEASSIGN,
187     };
188 
189     if (!vdev->intx.kvm_accel) {
190         return;
191     }
192 
193     /*
194      * Get to a known state, hardware masked, QEMU ready to accept new
195      * interrupts, QEMU IRQ de-asserted.
196      */
197     vfio_mask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
198     vdev->intx.pending = false;
199     pci_irq_deassert(&vdev->pdev);
200 
201     /* Tell KVM to stop listening for an INTx irqfd */
202     if (kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd)) {
203         error_report("vfio: Error: Failed to disable INTx irqfd: %m");
204     }
205 
206     /* We only need to close the eventfd for VFIO to cleanup the kernel side */
207     event_notifier_cleanup(&vdev->intx.unmask);
208 
209     /* QEMU starts listening for interrupt events. */
210     qemu_set_fd_handler(irqfd.fd, vfio_intx_interrupt, NULL, vdev);
211 
212     vdev->intx.kvm_accel = false;
213 
214     /* If we've missed an event, let it re-fire through QEMU */
215     vfio_unmask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
216 
217     trace_vfio_intx_disable_kvm(vdev->vbasedev.name);
218 #endif
219 }
220 
221 static void vfio_intx_update(PCIDevice *pdev)
222 {
223     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
224     PCIINTxRoute route;
225 
226     if (vdev->interrupt != VFIO_INT_INTx) {
227         return;
228     }
229 
230     route = pci_device_route_intx_to_irq(&vdev->pdev, vdev->intx.pin);
231 
232     if (!pci_intx_route_changed(&vdev->intx.route, &route)) {
233         return; /* Nothing changed */
234     }
235 
236     trace_vfio_intx_update(vdev->vbasedev.name,
237                            vdev->intx.route.irq, route.irq);
238 
239     vfio_intx_disable_kvm(vdev);
240 
241     vdev->intx.route = route;
242 
243     if (route.mode != PCI_INTX_ENABLED) {
244         return;
245     }
246 
247     vfio_intx_enable_kvm(vdev);
248 
249     /* Re-enable the interrupt in cased we missed an EOI */
250     vfio_intx_eoi(&vdev->vbasedev);
251 }
252 
253 static int vfio_intx_enable(VFIOPCIDevice *vdev)
254 {
255     uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
256     int ret, argsz;
257     struct vfio_irq_set *irq_set;
258     int32_t *pfd;
259 
260     if (!pin) {
261         return 0;
262     }
263 
264     vfio_disable_interrupts(vdev);
265 
266     vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */
267     pci_config_set_interrupt_pin(vdev->pdev.config, pin);
268 
269 #ifdef CONFIG_KVM
270     /*
271      * Only conditional to avoid generating error messages on platforms
272      * where we won't actually use the result anyway.
273      */
274     if (kvm_irqfds_enabled() && kvm_resamplefds_enabled()) {
275         vdev->intx.route = pci_device_route_intx_to_irq(&vdev->pdev,
276                                                         vdev->intx.pin);
277     }
278 #endif
279 
280     ret = event_notifier_init(&vdev->intx.interrupt, 0);
281     if (ret) {
282         error_report("vfio: Error: event_notifier_init failed");
283         return ret;
284     }
285 
286     argsz = sizeof(*irq_set) + sizeof(*pfd);
287 
288     irq_set = g_malloc0(argsz);
289     irq_set->argsz = argsz;
290     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
291     irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
292     irq_set->start = 0;
293     irq_set->count = 1;
294     pfd = (int32_t *)&irq_set->data;
295 
296     *pfd = event_notifier_get_fd(&vdev->intx.interrupt);
297     qemu_set_fd_handler(*pfd, vfio_intx_interrupt, NULL, vdev);
298 
299     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
300     g_free(irq_set);
301     if (ret) {
302         error_report("vfio: Error: Failed to setup INTx fd: %m");
303         qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
304         event_notifier_cleanup(&vdev->intx.interrupt);
305         return -errno;
306     }
307 
308     vfio_intx_enable_kvm(vdev);
309 
310     vdev->interrupt = VFIO_INT_INTx;
311 
312     trace_vfio_intx_enable(vdev->vbasedev.name);
313 
314     return 0;
315 }
316 
317 static void vfio_intx_disable(VFIOPCIDevice *vdev)
318 {
319     int fd;
320 
321     timer_del(vdev->intx.mmap_timer);
322     vfio_intx_disable_kvm(vdev);
323     vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX);
324     vdev->intx.pending = false;
325     pci_irq_deassert(&vdev->pdev);
326     vfio_mmap_set_enabled(vdev, true);
327 
328     fd = event_notifier_get_fd(&vdev->intx.interrupt);
329     qemu_set_fd_handler(fd, NULL, NULL, vdev);
330     event_notifier_cleanup(&vdev->intx.interrupt);
331 
332     vdev->interrupt = VFIO_INT_NONE;
333 
334     trace_vfio_intx_disable(vdev->vbasedev.name);
335 }
336 
337 /*
338  * MSI/X
339  */
340 static void vfio_msi_interrupt(void *opaque)
341 {
342     VFIOMSIVector *vector = opaque;
343     VFIOPCIDevice *vdev = vector->vdev;
344     MSIMessage (*get_msg)(PCIDevice *dev, unsigned vector);
345     void (*notify)(PCIDevice *dev, unsigned vector);
346     MSIMessage msg;
347     int nr = vector - vdev->msi_vectors;
348 
349     if (!event_notifier_test_and_clear(&vector->interrupt)) {
350         return;
351     }
352 
353     if (vdev->interrupt == VFIO_INT_MSIX) {
354         get_msg = msix_get_message;
355         notify = msix_notify;
356 
357         /* A masked vector firing needs to use the PBA, enable it */
358         if (msix_is_masked(&vdev->pdev, nr)) {
359             set_bit(nr, vdev->msix->pending);
360             memory_region_set_enabled(&vdev->pdev.msix_pba_mmio, true);
361             trace_vfio_msix_pba_enable(vdev->vbasedev.name);
362         }
363     } else if (vdev->interrupt == VFIO_INT_MSI) {
364         get_msg = msi_get_message;
365         notify = msi_notify;
366     } else {
367         abort();
368     }
369 
370     msg = get_msg(&vdev->pdev, nr);
371     trace_vfio_msi_interrupt(vdev->vbasedev.name, nr, msg.address, msg.data);
372     notify(&vdev->pdev, nr);
373 }
374 
375 static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix)
376 {
377     struct vfio_irq_set *irq_set;
378     int ret = 0, i, argsz;
379     int32_t *fds;
380 
381     argsz = sizeof(*irq_set) + (vdev->nr_vectors * sizeof(*fds));
382 
383     irq_set = g_malloc0(argsz);
384     irq_set->argsz = argsz;
385     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
386     irq_set->index = msix ? VFIO_PCI_MSIX_IRQ_INDEX : VFIO_PCI_MSI_IRQ_INDEX;
387     irq_set->start = 0;
388     irq_set->count = vdev->nr_vectors;
389     fds = (int32_t *)&irq_set->data;
390 
391     for (i = 0; i < vdev->nr_vectors; i++) {
392         int fd = -1;
393 
394         /*
395          * MSI vs MSI-X - The guest has direct access to MSI mask and pending
396          * bits, therefore we always use the KVM signaling path when setup.
397          * MSI-X mask and pending bits are emulated, so we want to use the
398          * KVM signaling path only when configured and unmasked.
399          */
400         if (vdev->msi_vectors[i].use) {
401             if (vdev->msi_vectors[i].virq < 0 ||
402                 (msix && msix_is_masked(&vdev->pdev, i))) {
403                 fd = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
404             } else {
405                 fd = event_notifier_get_fd(&vdev->msi_vectors[i].kvm_interrupt);
406             }
407         }
408 
409         fds[i] = fd;
410     }
411 
412     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
413 
414     g_free(irq_set);
415 
416     return ret;
417 }
418 
419 static void vfio_add_kvm_msi_virq(VFIOPCIDevice *vdev, VFIOMSIVector *vector,
420                                   MSIMessage *msg, bool msix)
421 {
422     int virq;
423 
424     if ((msix && vdev->no_kvm_msix) || (!msix && vdev->no_kvm_msi) || !msg) {
425         return;
426     }
427 
428     if (event_notifier_init(&vector->kvm_interrupt, 0)) {
429         return;
430     }
431 
432     virq = kvm_irqchip_add_msi_route(kvm_state, *msg, &vdev->pdev);
433     if (virq < 0) {
434         event_notifier_cleanup(&vector->kvm_interrupt);
435         return;
436     }
437 
438     if (kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, &vector->kvm_interrupt,
439                                        NULL, virq) < 0) {
440         kvm_irqchip_release_virq(kvm_state, virq);
441         event_notifier_cleanup(&vector->kvm_interrupt);
442         return;
443     }
444 
445     vector->virq = virq;
446 }
447 
448 static void vfio_remove_kvm_msi_virq(VFIOMSIVector *vector)
449 {
450     kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, &vector->kvm_interrupt,
451                                           vector->virq);
452     kvm_irqchip_release_virq(kvm_state, vector->virq);
453     vector->virq = -1;
454     event_notifier_cleanup(&vector->kvm_interrupt);
455 }
456 
457 static void vfio_update_kvm_msi_virq(VFIOMSIVector *vector, MSIMessage msg,
458                                      PCIDevice *pdev)
459 {
460     kvm_irqchip_update_msi_route(kvm_state, vector->virq, msg, pdev);
461 }
462 
463 static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
464                                    MSIMessage *msg, IOHandler *handler)
465 {
466     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
467     VFIOMSIVector *vector;
468     int ret;
469 
470     trace_vfio_msix_vector_do_use(vdev->vbasedev.name, nr);
471 
472     vector = &vdev->msi_vectors[nr];
473 
474     if (!vector->use) {
475         vector->vdev = vdev;
476         vector->virq = -1;
477         if (event_notifier_init(&vector->interrupt, 0)) {
478             error_report("vfio: Error: event_notifier_init failed");
479         }
480         vector->use = true;
481         msix_vector_use(pdev, nr);
482     }
483 
484     qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
485                         handler, NULL, vector);
486 
487     /*
488      * Attempt to enable route through KVM irqchip,
489      * default to userspace handling if unavailable.
490      */
491     if (vector->virq >= 0) {
492         if (!msg) {
493             vfio_remove_kvm_msi_virq(vector);
494         } else {
495             vfio_update_kvm_msi_virq(vector, *msg, pdev);
496         }
497     } else {
498         vfio_add_kvm_msi_virq(vdev, vector, msg, true);
499     }
500 
501     /*
502      * We don't want to have the host allocate all possible MSI vectors
503      * for a device if they're not in use, so we shutdown and incrementally
504      * increase them as needed.
505      */
506     if (vdev->nr_vectors < nr + 1) {
507         vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX);
508         vdev->nr_vectors = nr + 1;
509         ret = vfio_enable_vectors(vdev, true);
510         if (ret) {
511             error_report("vfio: failed to enable vectors, %d", ret);
512         }
513     } else {
514         int argsz;
515         struct vfio_irq_set *irq_set;
516         int32_t *pfd;
517 
518         argsz = sizeof(*irq_set) + sizeof(*pfd);
519 
520         irq_set = g_malloc0(argsz);
521         irq_set->argsz = argsz;
522         irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
523                          VFIO_IRQ_SET_ACTION_TRIGGER;
524         irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX;
525         irq_set->start = nr;
526         irq_set->count = 1;
527         pfd = (int32_t *)&irq_set->data;
528 
529         if (vector->virq >= 0) {
530             *pfd = event_notifier_get_fd(&vector->kvm_interrupt);
531         } else {
532             *pfd = event_notifier_get_fd(&vector->interrupt);
533         }
534 
535         ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
536         g_free(irq_set);
537         if (ret) {
538             error_report("vfio: failed to modify vector, %d", ret);
539         }
540     }
541 
542     /* Disable PBA emulation when nothing more is pending. */
543     clear_bit(nr, vdev->msix->pending);
544     if (find_first_bit(vdev->msix->pending,
545                        vdev->nr_vectors) == vdev->nr_vectors) {
546         memory_region_set_enabled(&vdev->pdev.msix_pba_mmio, false);
547         trace_vfio_msix_pba_disable(vdev->vbasedev.name);
548     }
549 
550     return 0;
551 }
552 
553 static int vfio_msix_vector_use(PCIDevice *pdev,
554                                 unsigned int nr, MSIMessage msg)
555 {
556     return vfio_msix_vector_do_use(pdev, nr, &msg, vfio_msi_interrupt);
557 }
558 
559 static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
560 {
561     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
562     VFIOMSIVector *vector = &vdev->msi_vectors[nr];
563 
564     trace_vfio_msix_vector_release(vdev->vbasedev.name, nr);
565 
566     /*
567      * There are still old guests that mask and unmask vectors on every
568      * interrupt.  If we're using QEMU bypass with a KVM irqfd, leave all of
569      * the KVM setup in place, simply switch VFIO to use the non-bypass
570      * eventfd.  We'll then fire the interrupt through QEMU and the MSI-X
571      * core will mask the interrupt and set pending bits, allowing it to
572      * be re-asserted on unmask.  Nothing to do if already using QEMU mode.
573      */
574     if (vector->virq >= 0) {
575         int argsz;
576         struct vfio_irq_set *irq_set;
577         int32_t *pfd;
578 
579         argsz = sizeof(*irq_set) + sizeof(*pfd);
580 
581         irq_set = g_malloc0(argsz);
582         irq_set->argsz = argsz;
583         irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
584                          VFIO_IRQ_SET_ACTION_TRIGGER;
585         irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX;
586         irq_set->start = nr;
587         irq_set->count = 1;
588         pfd = (int32_t *)&irq_set->data;
589 
590         *pfd = event_notifier_get_fd(&vector->interrupt);
591 
592         ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
593 
594         g_free(irq_set);
595     }
596 }
597 
598 static void vfio_msix_enable(VFIOPCIDevice *vdev)
599 {
600     vfio_disable_interrupts(vdev);
601 
602     vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->msix->entries);
603 
604     vdev->interrupt = VFIO_INT_MSIX;
605 
606     /*
607      * Some communication channels between VF & PF or PF & fw rely on the
608      * physical state of the device and expect that enabling MSI-X from the
609      * guest enables the same on the host.  When our guest is Linux, the
610      * guest driver call to pci_enable_msix() sets the enabling bit in the
611      * MSI-X capability, but leaves the vector table masked.  We therefore
612      * can't rely on a vector_use callback (from request_irq() in the guest)
613      * to switch the physical device into MSI-X mode because that may come a
614      * long time after pci_enable_msix().  This code enables vector 0 with
615      * triggering to userspace, then immediately release the vector, leaving
616      * the physical device with no vectors enabled, but MSI-X enabled, just
617      * like the guest view.
618      */
619     vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL);
620     vfio_msix_vector_release(&vdev->pdev, 0);
621 
622     if (msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use,
623                                   vfio_msix_vector_release, NULL)) {
624         error_report("vfio: msix_set_vector_notifiers failed");
625     }
626 
627     trace_vfio_msix_enable(vdev->vbasedev.name);
628 }
629 
630 static void vfio_msi_enable(VFIOPCIDevice *vdev)
631 {
632     int ret, i;
633 
634     vfio_disable_interrupts(vdev);
635 
636     vdev->nr_vectors = msi_nr_vectors_allocated(&vdev->pdev);
637 retry:
638     vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->nr_vectors);
639 
640     for (i = 0; i < vdev->nr_vectors; i++) {
641         VFIOMSIVector *vector = &vdev->msi_vectors[i];
642         MSIMessage msg = msi_get_message(&vdev->pdev, i);
643 
644         vector->vdev = vdev;
645         vector->virq = -1;
646         vector->use = true;
647 
648         if (event_notifier_init(&vector->interrupt, 0)) {
649             error_report("vfio: Error: event_notifier_init failed");
650         }
651 
652         qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
653                             vfio_msi_interrupt, NULL, vector);
654 
655         /*
656          * Attempt to enable route through KVM irqchip,
657          * default to userspace handling if unavailable.
658          */
659         vfio_add_kvm_msi_virq(vdev, vector, &msg, false);
660     }
661 
662     /* Set interrupt type prior to possible interrupts */
663     vdev->interrupt = VFIO_INT_MSI;
664 
665     ret = vfio_enable_vectors(vdev, false);
666     if (ret) {
667         if (ret < 0) {
668             error_report("vfio: Error: Failed to setup MSI fds: %m");
669         } else if (ret != vdev->nr_vectors) {
670             error_report("vfio: Error: Failed to enable %d "
671                          "MSI vectors, retry with %d", vdev->nr_vectors, ret);
672         }
673 
674         for (i = 0; i < vdev->nr_vectors; i++) {
675             VFIOMSIVector *vector = &vdev->msi_vectors[i];
676             if (vector->virq >= 0) {
677                 vfio_remove_kvm_msi_virq(vector);
678             }
679             qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
680                                 NULL, NULL, NULL);
681             event_notifier_cleanup(&vector->interrupt);
682         }
683 
684         g_free(vdev->msi_vectors);
685 
686         if (ret > 0 && ret != vdev->nr_vectors) {
687             vdev->nr_vectors = ret;
688             goto retry;
689         }
690         vdev->nr_vectors = 0;
691 
692         /*
693          * Failing to setup MSI doesn't really fall within any specification.
694          * Let's try leaving interrupts disabled and hope the guest figures
695          * out to fall back to INTx for this device.
696          */
697         error_report("vfio: Error: Failed to enable MSI");
698         vdev->interrupt = VFIO_INT_NONE;
699 
700         return;
701     }
702 
703     trace_vfio_msi_enable(vdev->vbasedev.name, vdev->nr_vectors);
704 }
705 
706 static void vfio_msi_disable_common(VFIOPCIDevice *vdev)
707 {
708     int i;
709 
710     for (i = 0; i < vdev->nr_vectors; i++) {
711         VFIOMSIVector *vector = &vdev->msi_vectors[i];
712         if (vdev->msi_vectors[i].use) {
713             if (vector->virq >= 0) {
714                 vfio_remove_kvm_msi_virq(vector);
715             }
716             qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
717                                 NULL, NULL, NULL);
718             event_notifier_cleanup(&vector->interrupt);
719         }
720     }
721 
722     g_free(vdev->msi_vectors);
723     vdev->msi_vectors = NULL;
724     vdev->nr_vectors = 0;
725     vdev->interrupt = VFIO_INT_NONE;
726 
727     vfio_intx_enable(vdev);
728 }
729 
730 static void vfio_msix_disable(VFIOPCIDevice *vdev)
731 {
732     int i;
733 
734     msix_unset_vector_notifiers(&vdev->pdev);
735 
736     /*
737      * MSI-X will only release vectors if MSI-X is still enabled on the
738      * device, check through the rest and release it ourselves if necessary.
739      */
740     for (i = 0; i < vdev->nr_vectors; i++) {
741         if (vdev->msi_vectors[i].use) {
742             vfio_msix_vector_release(&vdev->pdev, i);
743             msix_vector_unuse(&vdev->pdev, i);
744         }
745     }
746 
747     if (vdev->nr_vectors) {
748         vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX);
749     }
750 
751     vfio_msi_disable_common(vdev);
752 
753     memset(vdev->msix->pending, 0,
754            BITS_TO_LONGS(vdev->msix->entries) * sizeof(unsigned long));
755 
756     trace_vfio_msix_disable(vdev->vbasedev.name);
757 }
758 
759 static void vfio_msi_disable(VFIOPCIDevice *vdev)
760 {
761     vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSI_IRQ_INDEX);
762     vfio_msi_disable_common(vdev);
763 
764     trace_vfio_msi_disable(vdev->vbasedev.name);
765 }
766 
767 static void vfio_update_msi(VFIOPCIDevice *vdev)
768 {
769     int i;
770 
771     for (i = 0; i < vdev->nr_vectors; i++) {
772         VFIOMSIVector *vector = &vdev->msi_vectors[i];
773         MSIMessage msg;
774 
775         if (!vector->use || vector->virq < 0) {
776             continue;
777         }
778 
779         msg = msi_get_message(&vdev->pdev, i);
780         vfio_update_kvm_msi_virq(vector, msg, &vdev->pdev);
781     }
782 }
783 
784 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
785 {
786     struct vfio_region_info reg_info = {
787         .argsz = sizeof(reg_info),
788         .index = VFIO_PCI_ROM_REGION_INDEX
789     };
790     uint64_t size;
791     off_t off = 0;
792     ssize_t bytes;
793 
794     if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info)) {
795         error_report("vfio: Error getting ROM info: %m");
796         return;
797     }
798 
799     trace_vfio_pci_load_rom(vdev->vbasedev.name, (unsigned long)reg_info.size,
800                             (unsigned long)reg_info.offset,
801                             (unsigned long)reg_info.flags);
802 
803     vdev->rom_size = size = reg_info.size;
804     vdev->rom_offset = reg_info.offset;
805 
806     if (!vdev->rom_size) {
807         vdev->rom_read_failed = true;
808         error_report("vfio-pci: Cannot read device rom at "
809                     "%s", vdev->vbasedev.name);
810         error_printf("Device option ROM contents are probably invalid "
811                     "(check dmesg).\nSkip option ROM probe with rombar=0, "
812                     "or load from file with romfile=\n");
813         return;
814     }
815 
816     vdev->rom = g_malloc(size);
817     memset(vdev->rom, 0xff, size);
818 
819     while (size) {
820         bytes = pread(vdev->vbasedev.fd, vdev->rom + off,
821                       size, vdev->rom_offset + off);
822         if (bytes == 0) {
823             break;
824         } else if (bytes > 0) {
825             off += bytes;
826             size -= bytes;
827         } else {
828             if (errno == EINTR || errno == EAGAIN) {
829                 continue;
830             }
831             error_report("vfio: Error reading device ROM: %m");
832             break;
833         }
834     }
835 }
836 
837 static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)
838 {
839     VFIOPCIDevice *vdev = opaque;
840     union {
841         uint8_t byte;
842         uint16_t word;
843         uint32_t dword;
844         uint64_t qword;
845     } val;
846     uint64_t data = 0;
847 
848     /* Load the ROM lazily when the guest tries to read it */
849     if (unlikely(!vdev->rom && !vdev->rom_read_failed)) {
850         vfio_pci_load_rom(vdev);
851     }
852 
853     memcpy(&val, vdev->rom + addr,
854            (addr < vdev->rom_size) ? MIN(size, vdev->rom_size - addr) : 0);
855 
856     switch (size) {
857     case 1:
858         data = val.byte;
859         break;
860     case 2:
861         data = le16_to_cpu(val.word);
862         break;
863     case 4:
864         data = le32_to_cpu(val.dword);
865         break;
866     default:
867         hw_error("vfio: unsupported read size, %d bytes\n", size);
868         break;
869     }
870 
871     trace_vfio_rom_read(vdev->vbasedev.name, addr, size, data);
872 
873     return data;
874 }
875 
876 static void vfio_rom_write(void *opaque, hwaddr addr,
877                            uint64_t data, unsigned size)
878 {
879 }
880 
881 static const MemoryRegionOps vfio_rom_ops = {
882     .read = vfio_rom_read,
883     .write = vfio_rom_write,
884     .endianness = DEVICE_LITTLE_ENDIAN,
885 };
886 
887 static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
888 {
889     uint32_t orig, size = cpu_to_le32((uint32_t)PCI_ROM_ADDRESS_MASK);
890     off_t offset = vdev->config_offset + PCI_ROM_ADDRESS;
891     DeviceState *dev = DEVICE(vdev);
892     char name[32];
893     int fd = vdev->vbasedev.fd;
894 
895     if (vdev->pdev.romfile || !vdev->pdev.rom_bar) {
896         /* Since pci handles romfile, just print a message and return */
897         if (vfio_blacklist_opt_rom(vdev) && vdev->pdev.romfile) {
898             error_printf("Warning : Device at %04x:%02x:%02x.%x "
899                          "is known to cause system instability issues during "
900                          "option rom execution. "
901                          "Proceeding anyway since user specified romfile\n",
902                          vdev->host.domain, vdev->host.bus, vdev->host.slot,
903                          vdev->host.function);
904         }
905         return;
906     }
907 
908     /*
909      * Use the same size ROM BAR as the physical device.  The contents
910      * will get filled in later when the guest tries to read it.
911      */
912     if (pread(fd, &orig, 4, offset) != 4 ||
913         pwrite(fd, &size, 4, offset) != 4 ||
914         pread(fd, &size, 4, offset) != 4 ||
915         pwrite(fd, &orig, 4, offset) != 4) {
916         error_report("%s(%04x:%02x:%02x.%x) failed: %m",
917                      __func__, vdev->host.domain, vdev->host.bus,
918                      vdev->host.slot, vdev->host.function);
919         return;
920     }
921 
922     size = ~(le32_to_cpu(size) & PCI_ROM_ADDRESS_MASK) + 1;
923 
924     if (!size) {
925         return;
926     }
927 
928     if (vfio_blacklist_opt_rom(vdev)) {
929         if (dev->opts && qemu_opt_get(dev->opts, "rombar")) {
930             error_printf("Warning : Device at %04x:%02x:%02x.%x "
931                          "is known to cause system instability issues during "
932                          "option rom execution. "
933                          "Proceeding anyway since user specified non zero value for "
934                          "rombar\n",
935                          vdev->host.domain, vdev->host.bus, vdev->host.slot,
936                          vdev->host.function);
937         } else {
938             error_printf("Warning : Rom loading for device at "
939                          "%04x:%02x:%02x.%x has been disabled due to "
940                          "system instability issues. "
941                          "Specify rombar=1 or romfile to force\n",
942                          vdev->host.domain, vdev->host.bus, vdev->host.slot,
943                          vdev->host.function);
944             return;
945         }
946     }
947 
948     trace_vfio_pci_size_rom(vdev->vbasedev.name, size);
949 
950     snprintf(name, sizeof(name), "vfio[%04x:%02x:%02x.%x].rom",
951              vdev->host.domain, vdev->host.bus, vdev->host.slot,
952              vdev->host.function);
953 
954     memory_region_init_io(&vdev->pdev.rom, OBJECT(vdev),
955                           &vfio_rom_ops, vdev, name, size);
956 
957     pci_register_bar(&vdev->pdev, PCI_ROM_SLOT,
958                      PCI_BASE_ADDRESS_SPACE_MEMORY, &vdev->pdev.rom);
959 
960     vdev->pdev.has_rom = true;
961     vdev->rom_read_failed = false;
962 }
963 
964 void vfio_vga_write(void *opaque, hwaddr addr,
965                            uint64_t data, unsigned size)
966 {
967     VFIOVGARegion *region = opaque;
968     VFIOVGA *vga = container_of(region, VFIOVGA, region[region->nr]);
969     union {
970         uint8_t byte;
971         uint16_t word;
972         uint32_t dword;
973         uint64_t qword;
974     } buf;
975     off_t offset = vga->fd_offset + region->offset + addr;
976 
977     switch (size) {
978     case 1:
979         buf.byte = data;
980         break;
981     case 2:
982         buf.word = cpu_to_le16(data);
983         break;
984     case 4:
985         buf.dword = cpu_to_le32(data);
986         break;
987     default:
988         hw_error("vfio: unsupported write size, %d bytes", size);
989         break;
990     }
991 
992     if (pwrite(vga->fd, &buf, size, offset) != size) {
993         error_report("%s(,0x%"HWADDR_PRIx", 0x%"PRIx64", %d) failed: %m",
994                      __func__, region->offset + addr, data, size);
995     }
996 
997     trace_vfio_vga_write(region->offset + addr, data, size);
998 }
999 
1000 uint64_t vfio_vga_read(void *opaque, hwaddr addr, unsigned size)
1001 {
1002     VFIOVGARegion *region = opaque;
1003     VFIOVGA *vga = container_of(region, VFIOVGA, region[region->nr]);
1004     union {
1005         uint8_t byte;
1006         uint16_t word;
1007         uint32_t dword;
1008         uint64_t qword;
1009     } buf;
1010     uint64_t data = 0;
1011     off_t offset = vga->fd_offset + region->offset + addr;
1012 
1013     if (pread(vga->fd, &buf, size, offset) != size) {
1014         error_report("%s(,0x%"HWADDR_PRIx", %d) failed: %m",
1015                      __func__, region->offset + addr, size);
1016         return (uint64_t)-1;
1017     }
1018 
1019     switch (size) {
1020     case 1:
1021         data = buf.byte;
1022         break;
1023     case 2:
1024         data = le16_to_cpu(buf.word);
1025         break;
1026     case 4:
1027         data = le32_to_cpu(buf.dword);
1028         break;
1029     default:
1030         hw_error("vfio: unsupported read size, %d bytes", size);
1031         break;
1032     }
1033 
1034     trace_vfio_vga_read(region->offset + addr, size, data);
1035 
1036     return data;
1037 }
1038 
1039 static const MemoryRegionOps vfio_vga_ops = {
1040     .read = vfio_vga_read,
1041     .write = vfio_vga_write,
1042     .endianness = DEVICE_LITTLE_ENDIAN,
1043 };
1044 
1045 /*
1046  * PCI config space
1047  */
1048 uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
1049 {
1050     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
1051     uint32_t emu_bits = 0, emu_val = 0, phys_val = 0, val;
1052 
1053     memcpy(&emu_bits, vdev->emulated_config_bits + addr, len);
1054     emu_bits = le32_to_cpu(emu_bits);
1055 
1056     if (emu_bits) {
1057         emu_val = pci_default_read_config(pdev, addr, len);
1058     }
1059 
1060     if (~emu_bits & (0xffffffffU >> (32 - len * 8))) {
1061         ssize_t ret;
1062 
1063         ret = pread(vdev->vbasedev.fd, &phys_val, len,
1064                     vdev->config_offset + addr);
1065         if (ret != len) {
1066             error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x) failed: %m",
1067                          __func__, vdev->host.domain, vdev->host.bus,
1068                          vdev->host.slot, vdev->host.function, addr, len);
1069             return -errno;
1070         }
1071         phys_val = le32_to_cpu(phys_val);
1072     }
1073 
1074     val = (emu_val & emu_bits) | (phys_val & ~emu_bits);
1075 
1076     trace_vfio_pci_read_config(vdev->vbasedev.name, addr, len, val);
1077 
1078     return val;
1079 }
1080 
1081 void vfio_pci_write_config(PCIDevice *pdev,
1082                            uint32_t addr, uint32_t val, int len)
1083 {
1084     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
1085     uint32_t val_le = cpu_to_le32(val);
1086 
1087     trace_vfio_pci_write_config(vdev->vbasedev.name, addr, val, len);
1088 
1089     /* Write everything to VFIO, let it filter out what we can't write */
1090     if (pwrite(vdev->vbasedev.fd, &val_le, len, vdev->config_offset + addr)
1091                 != len) {
1092         error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x, 0x%x) failed: %m",
1093                      __func__, vdev->host.domain, vdev->host.bus,
1094                      vdev->host.slot, vdev->host.function, addr, val, len);
1095     }
1096 
1097     /* MSI/MSI-X Enabling/Disabling */
1098     if (pdev->cap_present & QEMU_PCI_CAP_MSI &&
1099         ranges_overlap(addr, len, pdev->msi_cap, vdev->msi_cap_size)) {
1100         int is_enabled, was_enabled = msi_enabled(pdev);
1101 
1102         pci_default_write_config(pdev, addr, val, len);
1103 
1104         is_enabled = msi_enabled(pdev);
1105 
1106         if (!was_enabled) {
1107             if (is_enabled) {
1108                 vfio_msi_enable(vdev);
1109             }
1110         } else {
1111             if (!is_enabled) {
1112                 vfio_msi_disable(vdev);
1113             } else {
1114                 vfio_update_msi(vdev);
1115             }
1116         }
1117     } else if (pdev->cap_present & QEMU_PCI_CAP_MSIX &&
1118         ranges_overlap(addr, len, pdev->msix_cap, MSIX_CAP_LENGTH)) {
1119         int is_enabled, was_enabled = msix_enabled(pdev);
1120 
1121         pci_default_write_config(pdev, addr, val, len);
1122 
1123         is_enabled = msix_enabled(pdev);
1124 
1125         if (!was_enabled && is_enabled) {
1126             vfio_msix_enable(vdev);
1127         } else if (was_enabled && !is_enabled) {
1128             vfio_msix_disable(vdev);
1129         }
1130     } else {
1131         /* Write everything to QEMU to keep emulated bits correct */
1132         pci_default_write_config(pdev, addr, val, len);
1133     }
1134 }
1135 
1136 /*
1137  * Interrupt setup
1138  */
1139 static void vfio_disable_interrupts(VFIOPCIDevice *vdev)
1140 {
1141     /*
1142      * More complicated than it looks.  Disabling MSI/X transitions the
1143      * device to INTx mode (if supported).  Therefore we need to first
1144      * disable MSI/X and then cleanup by disabling INTx.
1145      */
1146     if (vdev->interrupt == VFIO_INT_MSIX) {
1147         vfio_msix_disable(vdev);
1148     } else if (vdev->interrupt == VFIO_INT_MSI) {
1149         vfio_msi_disable(vdev);
1150     }
1151 
1152     if (vdev->interrupt == VFIO_INT_INTx) {
1153         vfio_intx_disable(vdev);
1154     }
1155 }
1156 
1157 static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos)
1158 {
1159     uint16_t ctrl;
1160     bool msi_64bit, msi_maskbit;
1161     int ret, entries;
1162 
1163     if (pread(vdev->vbasedev.fd, &ctrl, sizeof(ctrl),
1164               vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
1165         return -errno;
1166     }
1167     ctrl = le16_to_cpu(ctrl);
1168 
1169     msi_64bit = !!(ctrl & PCI_MSI_FLAGS_64BIT);
1170     msi_maskbit = !!(ctrl & PCI_MSI_FLAGS_MASKBIT);
1171     entries = 1 << ((ctrl & PCI_MSI_FLAGS_QMASK) >> 1);
1172 
1173     trace_vfio_msi_setup(vdev->vbasedev.name, pos);
1174 
1175     ret = msi_init(&vdev->pdev, pos, entries, msi_64bit, msi_maskbit);
1176     if (ret < 0) {
1177         if (ret == -ENOTSUP) {
1178             return 0;
1179         }
1180         error_report("vfio: msi_init failed");
1181         return ret;
1182     }
1183     vdev->msi_cap_size = 0xa + (msi_maskbit ? 0xa : 0) + (msi_64bit ? 0x4 : 0);
1184 
1185     return 0;
1186 }
1187 
1188 /*
1189  * We don't have any control over how pci_add_capability() inserts
1190  * capabilities into the chain.  In order to setup MSI-X we need a
1191  * MemoryRegion for the BAR.  In order to setup the BAR and not
1192  * attempt to mmap the MSI-X table area, which VFIO won't allow, we
1193  * need to first look for where the MSI-X table lives.  So we
1194  * unfortunately split MSI-X setup across two functions.
1195  */
1196 static int vfio_msix_early_setup(VFIOPCIDevice *vdev)
1197 {
1198     uint8_t pos;
1199     uint16_t ctrl;
1200     uint32_t table, pba;
1201     int fd = vdev->vbasedev.fd;
1202     VFIOMSIXInfo *msix;
1203 
1204     pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
1205     if (!pos) {
1206         return 0;
1207     }
1208 
1209     if (pread(fd, &ctrl, sizeof(ctrl),
1210               vdev->config_offset + pos + PCI_MSIX_FLAGS) != sizeof(ctrl)) {
1211         return -errno;
1212     }
1213 
1214     if (pread(fd, &table, sizeof(table),
1215               vdev->config_offset + pos + PCI_MSIX_TABLE) != sizeof(table)) {
1216         return -errno;
1217     }
1218 
1219     if (pread(fd, &pba, sizeof(pba),
1220               vdev->config_offset + pos + PCI_MSIX_PBA) != sizeof(pba)) {
1221         return -errno;
1222     }
1223 
1224     ctrl = le16_to_cpu(ctrl);
1225     table = le32_to_cpu(table);
1226     pba = le32_to_cpu(pba);
1227 
1228     msix = g_malloc0(sizeof(*msix));
1229     msix->table_bar = table & PCI_MSIX_FLAGS_BIRMASK;
1230     msix->table_offset = table & ~PCI_MSIX_FLAGS_BIRMASK;
1231     msix->pba_bar = pba & PCI_MSIX_FLAGS_BIRMASK;
1232     msix->pba_offset = pba & ~PCI_MSIX_FLAGS_BIRMASK;
1233     msix->entries = (ctrl & PCI_MSIX_FLAGS_QSIZE) + 1;
1234 
1235     /*
1236      * Test the size of the pba_offset variable and catch if it extends outside
1237      * of the specified BAR. If it is the case, we need to apply a hardware
1238      * specific quirk if the device is known or we have a broken configuration.
1239      */
1240     if (msix->pba_offset >= vdev->bars[msix->pba_bar].region.size) {
1241         /*
1242          * Chelsio T5 Virtual Function devices are encoded as 0x58xx for T5
1243          * adapters. The T5 hardware returns an incorrect value of 0x8000 for
1244          * the VF PBA offset while the BAR itself is only 8k. The correct value
1245          * is 0x1000, so we hard code that here.
1246          */
1247         if (vdev->vendor_id == PCI_VENDOR_ID_CHELSIO &&
1248             (vdev->device_id & 0xff00) == 0x5800) {
1249             msix->pba_offset = 0x1000;
1250         } else {
1251             error_report("vfio: Hardware reports invalid configuration, "
1252                          "MSIX PBA outside of specified BAR");
1253             g_free(msix);
1254             return -EINVAL;
1255         }
1256     }
1257 
1258     trace_vfio_msix_early_setup(vdev->vbasedev.name, pos, msix->table_bar,
1259                                 msix->table_offset, msix->entries);
1260     vdev->msix = msix;
1261 
1262     return 0;
1263 }
1264 
1265 static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos)
1266 {
1267     int ret;
1268 
1269     vdev->msix->pending = g_malloc0(BITS_TO_LONGS(vdev->msix->entries) *
1270                                     sizeof(unsigned long));
1271     ret = msix_init(&vdev->pdev, vdev->msix->entries,
1272                     &vdev->bars[vdev->msix->table_bar].region.mem,
1273                     vdev->msix->table_bar, vdev->msix->table_offset,
1274                     &vdev->bars[vdev->msix->pba_bar].region.mem,
1275                     vdev->msix->pba_bar, vdev->msix->pba_offset, pos);
1276     if (ret < 0) {
1277         if (ret == -ENOTSUP) {
1278             return 0;
1279         }
1280         error_report("vfio: msix_init failed");
1281         return ret;
1282     }
1283 
1284     /*
1285      * The PCI spec suggests that devices provide additional alignment for
1286      * MSI-X structures and avoid overlapping non-MSI-X related registers.
1287      * For an assigned device, this hopefully means that emulation of MSI-X
1288      * structures does not affect the performance of the device.  If devices
1289      * fail to provide that alignment, a significant performance penalty may
1290      * result, for instance Mellanox MT27500 VFs:
1291      * http://www.spinics.net/lists/kvm/msg125881.html
1292      *
1293      * The PBA is simply not that important for such a serious regression and
1294      * most drivers do not appear to look at it.  The solution for this is to
1295      * disable the PBA MemoryRegion unless it's being used.  We disable it
1296      * here and only enable it if a masked vector fires through QEMU.  As the
1297      * vector-use notifier is called, which occurs on unmask, we test whether
1298      * PBA emulation is needed and again disable if not.
1299      */
1300     memory_region_set_enabled(&vdev->pdev.msix_pba_mmio, false);
1301 
1302     return 0;
1303 }
1304 
1305 static void vfio_teardown_msi(VFIOPCIDevice *vdev)
1306 {
1307     msi_uninit(&vdev->pdev);
1308 
1309     if (vdev->msix) {
1310         msix_uninit(&vdev->pdev,
1311                     &vdev->bars[vdev->msix->table_bar].region.mem,
1312                     &vdev->bars[vdev->msix->pba_bar].region.mem);
1313         g_free(vdev->msix->pending);
1314     }
1315 }
1316 
1317 /*
1318  * Resource setup
1319  */
1320 static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled)
1321 {
1322     int i;
1323 
1324     for (i = 0; i < PCI_ROM_SLOT; i++) {
1325         VFIOBAR *bar = &vdev->bars[i];
1326 
1327         if (!bar->region.size) {
1328             continue;
1329         }
1330 
1331         memory_region_set_enabled(&bar->region.mmap_mem, enabled);
1332         if (vdev->msix && vdev->msix->table_bar == i) {
1333             memory_region_set_enabled(&vdev->msix->mmap_mem, enabled);
1334         }
1335     }
1336 }
1337 
1338 static void vfio_unregister_bar(VFIOPCIDevice *vdev, int nr)
1339 {
1340     VFIOBAR *bar = &vdev->bars[nr];
1341 
1342     if (!bar->region.size) {
1343         return;
1344     }
1345 
1346     vfio_bar_quirk_teardown(vdev, nr);
1347 
1348     memory_region_del_subregion(&bar->region.mem, &bar->region.mmap_mem);
1349 
1350     if (vdev->msix && vdev->msix->table_bar == nr) {
1351         memory_region_del_subregion(&bar->region.mem, &vdev->msix->mmap_mem);
1352     }
1353 }
1354 
1355 static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
1356 {
1357     VFIOBAR *bar = &vdev->bars[nr];
1358 
1359     if (!bar->region.size) {
1360         return;
1361     }
1362 
1363     vfio_bar_quirk_free(vdev, nr);
1364 
1365     munmap(bar->region.mmap, memory_region_size(&bar->region.mmap_mem));
1366 
1367     if (vdev->msix && vdev->msix->table_bar == nr) {
1368         munmap(vdev->msix->mmap, memory_region_size(&vdev->msix->mmap_mem));
1369     }
1370 }
1371 
1372 static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
1373 {
1374     VFIOBAR *bar = &vdev->bars[nr];
1375     uint64_t size = bar->region.size;
1376     char name[64];
1377     uint32_t pci_bar;
1378     uint8_t type;
1379     int ret;
1380 
1381     /* Skip both unimplemented BARs and the upper half of 64bit BARS. */
1382     if (!size) {
1383         return;
1384     }
1385 
1386     snprintf(name, sizeof(name), "VFIO %04x:%02x:%02x.%x BAR %d",
1387              vdev->host.domain, vdev->host.bus, vdev->host.slot,
1388              vdev->host.function, nr);
1389 
1390     /* Determine what type of BAR this is for registration */
1391     ret = pread(vdev->vbasedev.fd, &pci_bar, sizeof(pci_bar),
1392                 vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
1393     if (ret != sizeof(pci_bar)) {
1394         error_report("vfio: Failed to read BAR %d (%m)", nr);
1395         return;
1396     }
1397 
1398     pci_bar = le32_to_cpu(pci_bar);
1399     bar->ioport = (pci_bar & PCI_BASE_ADDRESS_SPACE_IO);
1400     bar->mem64 = bar->ioport ? 0 : (pci_bar & PCI_BASE_ADDRESS_MEM_TYPE_64);
1401     type = pci_bar & (bar->ioport ? ~PCI_BASE_ADDRESS_IO_MASK :
1402                                     ~PCI_BASE_ADDRESS_MEM_MASK);
1403 
1404     /* A "slow" read/write mapping underlies all BARs */
1405     memory_region_init_io(&bar->region.mem, OBJECT(vdev), &vfio_region_ops,
1406                           bar, name, size);
1407     pci_register_bar(&vdev->pdev, nr, type, &bar->region.mem);
1408 
1409     /*
1410      * We can't mmap areas overlapping the MSIX vector table, so we
1411      * potentially insert a direct-mapped subregion before and after it.
1412      */
1413     if (vdev->msix && vdev->msix->table_bar == nr) {
1414         size = vdev->msix->table_offset & qemu_real_host_page_mask;
1415     }
1416 
1417     strncat(name, " mmap", sizeof(name) - strlen(name) - 1);
1418     if (vfio_mmap_region(OBJECT(vdev), &bar->region, &bar->region.mem,
1419                       &bar->region.mmap_mem, &bar->region.mmap,
1420                       size, 0, name)) {
1421         error_report("%s unsupported. Performance may be slow", name);
1422     }
1423 
1424     if (vdev->msix && vdev->msix->table_bar == nr) {
1425         uint64_t start;
1426 
1427         start = REAL_HOST_PAGE_ALIGN((uint64_t)vdev->msix->table_offset +
1428                                      (vdev->msix->entries *
1429                                       PCI_MSIX_ENTRY_SIZE));
1430 
1431         size = start < bar->region.size ? bar->region.size - start : 0;
1432         strncat(name, " msix-hi", sizeof(name) - strlen(name) - 1);
1433         /* VFIOMSIXInfo contains another MemoryRegion for this mapping */
1434         if (vfio_mmap_region(OBJECT(vdev), &bar->region, &bar->region.mem,
1435                           &vdev->msix->mmap_mem,
1436                           &vdev->msix->mmap, size, start, name)) {
1437             error_report("%s unsupported. Performance may be slow", name);
1438         }
1439     }
1440 
1441     vfio_bar_quirk_setup(vdev, nr);
1442 }
1443 
1444 static void vfio_map_bars(VFIOPCIDevice *vdev)
1445 {
1446     int i;
1447 
1448     for (i = 0; i < PCI_ROM_SLOT; i++) {
1449         vfio_map_bar(vdev, i);
1450     }
1451 
1452     if (vdev->has_vga) {
1453         memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_MEM].mem,
1454                               OBJECT(vdev), &vfio_vga_ops,
1455                               &vdev->vga.region[QEMU_PCI_VGA_MEM],
1456                               "vfio-vga-mmio@0xa0000",
1457                               QEMU_PCI_VGA_MEM_SIZE);
1458         memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_IO_LO].mem,
1459                               OBJECT(vdev), &vfio_vga_ops,
1460                               &vdev->vga.region[QEMU_PCI_VGA_IO_LO],
1461                               "vfio-vga-io@0x3b0",
1462                               QEMU_PCI_VGA_IO_LO_SIZE);
1463         memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem,
1464                               OBJECT(vdev), &vfio_vga_ops,
1465                               &vdev->vga.region[QEMU_PCI_VGA_IO_HI],
1466                               "vfio-vga-io@0x3c0",
1467                               QEMU_PCI_VGA_IO_HI_SIZE);
1468 
1469         pci_register_vga(&vdev->pdev, &vdev->vga.region[QEMU_PCI_VGA_MEM].mem,
1470                          &vdev->vga.region[QEMU_PCI_VGA_IO_LO].mem,
1471                          &vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem);
1472         vfio_vga_quirk_setup(vdev);
1473     }
1474 }
1475 
1476 static void vfio_unregister_bars(VFIOPCIDevice *vdev)
1477 {
1478     int i;
1479 
1480     for (i = 0; i < PCI_ROM_SLOT; i++) {
1481         vfio_unregister_bar(vdev, i);
1482     }
1483 
1484     if (vdev->has_vga) {
1485         vfio_vga_quirk_teardown(vdev);
1486         pci_unregister_vga(&vdev->pdev);
1487     }
1488 }
1489 
1490 static void vfio_unmap_bars(VFIOPCIDevice *vdev)
1491 {
1492     int i;
1493 
1494     for (i = 0; i < PCI_ROM_SLOT; i++) {
1495         vfio_unmap_bar(vdev, i);
1496     }
1497 
1498     if (vdev->has_vga) {
1499         vfio_vga_quirk_free(vdev);
1500     }
1501 }
1502 
1503 /*
1504  * General setup
1505  */
1506 static uint8_t vfio_std_cap_max_size(PCIDevice *pdev, uint8_t pos)
1507 {
1508     uint8_t tmp;
1509     uint16_t next = PCI_CONFIG_SPACE_SIZE;
1510 
1511     for (tmp = pdev->config[PCI_CAPABILITY_LIST]; tmp;
1512          tmp = pdev->config[tmp + PCI_CAP_LIST_NEXT]) {
1513         if (tmp > pos && tmp < next) {
1514             next = tmp;
1515         }
1516     }
1517 
1518     return next - pos;
1519 }
1520 
1521 static void vfio_set_word_bits(uint8_t *buf, uint16_t val, uint16_t mask)
1522 {
1523     pci_set_word(buf, (pci_get_word(buf) & ~mask) | val);
1524 }
1525 
1526 static void vfio_add_emulated_word(VFIOPCIDevice *vdev, int pos,
1527                                    uint16_t val, uint16_t mask)
1528 {
1529     vfio_set_word_bits(vdev->pdev.config + pos, val, mask);
1530     vfio_set_word_bits(vdev->pdev.wmask + pos, ~mask, mask);
1531     vfio_set_word_bits(vdev->emulated_config_bits + pos, mask, mask);
1532 }
1533 
1534 static void vfio_set_long_bits(uint8_t *buf, uint32_t val, uint32_t mask)
1535 {
1536     pci_set_long(buf, (pci_get_long(buf) & ~mask) | val);
1537 }
1538 
1539 static void vfio_add_emulated_long(VFIOPCIDevice *vdev, int pos,
1540                                    uint32_t val, uint32_t mask)
1541 {
1542     vfio_set_long_bits(vdev->pdev.config + pos, val, mask);
1543     vfio_set_long_bits(vdev->pdev.wmask + pos, ~mask, mask);
1544     vfio_set_long_bits(vdev->emulated_config_bits + pos, mask, mask);
1545 }
1546 
1547 static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size)
1548 {
1549     uint16_t flags;
1550     uint8_t type;
1551 
1552     flags = pci_get_word(vdev->pdev.config + pos + PCI_CAP_FLAGS);
1553     type = (flags & PCI_EXP_FLAGS_TYPE) >> 4;
1554 
1555     if (type != PCI_EXP_TYPE_ENDPOINT &&
1556         type != PCI_EXP_TYPE_LEG_END &&
1557         type != PCI_EXP_TYPE_RC_END) {
1558 
1559         error_report("vfio: Assignment of PCIe type 0x%x "
1560                      "devices is not currently supported", type);
1561         return -EINVAL;
1562     }
1563 
1564     if (!pci_bus_is_express(vdev->pdev.bus)) {
1565         PCIBus *bus = vdev->pdev.bus;
1566         PCIDevice *bridge;
1567 
1568         /*
1569          * Traditionally PCI device assignment exposes the PCIe capability
1570          * as-is on non-express buses.  The reason being that some drivers
1571          * simply assume that it's there, for example tg3.  However when
1572          * we're running on a native PCIe machine type, like Q35, we need
1573          * to hide the PCIe capability.  The reason for this is twofold;
1574          * first Windows guests get a Code 10 error when the PCIe capability
1575          * is exposed in this configuration.  Therefore express devices won't
1576          * work at all unless they're attached to express buses in the VM.
1577          * Second, a native PCIe machine introduces the possibility of fine
1578          * granularity IOMMUs supporting both translation and isolation.
1579          * Guest code to discover the IOMMU visibility of a device, such as
1580          * IOMMU grouping code on Linux, is very aware of device types and
1581          * valid transitions between bus types.  An express device on a non-
1582          * express bus is not a valid combination on bare metal systems.
1583          *
1584          * Drivers that require a PCIe capability to make the device
1585          * functional are simply going to need to have their devices placed
1586          * on a PCIe bus in the VM.
1587          */
1588         while (!pci_bus_is_root(bus)) {
1589             bridge = pci_bridge_get_device(bus);
1590             bus = bridge->bus;
1591         }
1592 
1593         if (pci_bus_is_express(bus)) {
1594             return 0;
1595         }
1596 
1597     } else if (pci_bus_is_root(vdev->pdev.bus)) {
1598         /*
1599          * On a Root Complex bus Endpoints become Root Complex Integrated
1600          * Endpoints, which changes the type and clears the LNK & LNK2 fields.
1601          */
1602         if (type == PCI_EXP_TYPE_ENDPOINT) {
1603             vfio_add_emulated_word(vdev, pos + PCI_CAP_FLAGS,
1604                                    PCI_EXP_TYPE_RC_END << 4,
1605                                    PCI_EXP_FLAGS_TYPE);
1606 
1607             /* Link Capabilities, Status, and Control goes away */
1608             if (size > PCI_EXP_LNKCTL) {
1609                 vfio_add_emulated_long(vdev, pos + PCI_EXP_LNKCAP, 0, ~0);
1610                 vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKCTL, 0, ~0);
1611                 vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKSTA, 0, ~0);
1612 
1613 #ifndef PCI_EXP_LNKCAP2
1614 #define PCI_EXP_LNKCAP2 44
1615 #endif
1616 #ifndef PCI_EXP_LNKSTA2
1617 #define PCI_EXP_LNKSTA2 50
1618 #endif
1619                 /* Link 2 Capabilities, Status, and Control goes away */
1620                 if (size > PCI_EXP_LNKCAP2) {
1621                     vfio_add_emulated_long(vdev, pos + PCI_EXP_LNKCAP2, 0, ~0);
1622                     vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKCTL2, 0, ~0);
1623                     vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKSTA2, 0, ~0);
1624                 }
1625             }
1626 
1627         } else if (type == PCI_EXP_TYPE_LEG_END) {
1628             /*
1629              * Legacy endpoints don't belong on the root complex.  Windows
1630              * seems to be happier with devices if we skip the capability.
1631              */
1632             return 0;
1633         }
1634 
1635     } else {
1636         /*
1637          * Convert Root Complex Integrated Endpoints to regular endpoints.
1638          * These devices don't support LNK/LNK2 capabilities, so make them up.
1639          */
1640         if (type == PCI_EXP_TYPE_RC_END) {
1641             vfio_add_emulated_word(vdev, pos + PCI_CAP_FLAGS,
1642                                    PCI_EXP_TYPE_ENDPOINT << 4,
1643                                    PCI_EXP_FLAGS_TYPE);
1644             vfio_add_emulated_long(vdev, pos + PCI_EXP_LNKCAP,
1645                                    PCI_EXP_LNK_MLW_1 | PCI_EXP_LNK_LS_25, ~0);
1646             vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKCTL, 0, ~0);
1647         }
1648 
1649         /* Mark the Link Status bits as emulated to allow virtual negotiation */
1650         vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKSTA,
1651                                pci_get_word(vdev->pdev.config + pos +
1652                                             PCI_EXP_LNKSTA),
1653                                PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
1654     }
1655 
1656     pos = pci_add_capability(&vdev->pdev, PCI_CAP_ID_EXP, pos, size);
1657     if (pos >= 0) {
1658         vdev->pdev.exp.exp_cap = pos;
1659     }
1660 
1661     return pos;
1662 }
1663 
1664 static void vfio_check_pcie_flr(VFIOPCIDevice *vdev, uint8_t pos)
1665 {
1666     uint32_t cap = pci_get_long(vdev->pdev.config + pos + PCI_EXP_DEVCAP);
1667 
1668     if (cap & PCI_EXP_DEVCAP_FLR) {
1669         trace_vfio_check_pcie_flr(vdev->vbasedev.name);
1670         vdev->has_flr = true;
1671     }
1672 }
1673 
1674 static void vfio_check_pm_reset(VFIOPCIDevice *vdev, uint8_t pos)
1675 {
1676     uint16_t csr = pci_get_word(vdev->pdev.config + pos + PCI_PM_CTRL);
1677 
1678     if (!(csr & PCI_PM_CTRL_NO_SOFT_RESET)) {
1679         trace_vfio_check_pm_reset(vdev->vbasedev.name);
1680         vdev->has_pm_reset = true;
1681     }
1682 }
1683 
1684 static void vfio_check_af_flr(VFIOPCIDevice *vdev, uint8_t pos)
1685 {
1686     uint8_t cap = pci_get_byte(vdev->pdev.config + pos + PCI_AF_CAP);
1687 
1688     if ((cap & PCI_AF_CAP_TP) && (cap & PCI_AF_CAP_FLR)) {
1689         trace_vfio_check_af_flr(vdev->vbasedev.name);
1690         vdev->has_flr = true;
1691     }
1692 }
1693 
1694 static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos)
1695 {
1696     PCIDevice *pdev = &vdev->pdev;
1697     uint8_t cap_id, next, size;
1698     int ret;
1699 
1700     cap_id = pdev->config[pos];
1701     next = pdev->config[pos + PCI_CAP_LIST_NEXT];
1702 
1703     /*
1704      * If it becomes important to configure capabilities to their actual
1705      * size, use this as the default when it's something we don't recognize.
1706      * Since QEMU doesn't actually handle many of the config accesses,
1707      * exact size doesn't seem worthwhile.
1708      */
1709     size = vfio_std_cap_max_size(pdev, pos);
1710 
1711     /*
1712      * pci_add_capability always inserts the new capability at the head
1713      * of the chain.  Therefore to end up with a chain that matches the
1714      * physical device, we insert from the end by making this recursive.
1715      * This is also why we pre-calculate size above as cached config space
1716      * will be changed as we unwind the stack.
1717      */
1718     if (next) {
1719         ret = vfio_add_std_cap(vdev, next);
1720         if (ret) {
1721             return ret;
1722         }
1723     } else {
1724         /* Begin the rebuild, use QEMU emulated list bits */
1725         pdev->config[PCI_CAPABILITY_LIST] = 0;
1726         vdev->emulated_config_bits[PCI_CAPABILITY_LIST] = 0xff;
1727         vdev->emulated_config_bits[PCI_STATUS] |= PCI_STATUS_CAP_LIST;
1728     }
1729 
1730     /* Use emulated next pointer to allow dropping caps */
1731     pci_set_byte(vdev->emulated_config_bits + pos + PCI_CAP_LIST_NEXT, 0xff);
1732 
1733     switch (cap_id) {
1734     case PCI_CAP_ID_MSI:
1735         ret = vfio_msi_setup(vdev, pos);
1736         break;
1737     case PCI_CAP_ID_EXP:
1738         vfio_check_pcie_flr(vdev, pos);
1739         ret = vfio_setup_pcie_cap(vdev, pos, size);
1740         break;
1741     case PCI_CAP_ID_MSIX:
1742         ret = vfio_msix_setup(vdev, pos);
1743         break;
1744     case PCI_CAP_ID_PM:
1745         vfio_check_pm_reset(vdev, pos);
1746         vdev->pm_cap = pos;
1747         ret = pci_add_capability(pdev, cap_id, pos, size);
1748         break;
1749     case PCI_CAP_ID_AF:
1750         vfio_check_af_flr(vdev, pos);
1751         ret = pci_add_capability(pdev, cap_id, pos, size);
1752         break;
1753     default:
1754         ret = pci_add_capability(pdev, cap_id, pos, size);
1755         break;
1756     }
1757 
1758     if (ret < 0) {
1759         error_report("vfio: %04x:%02x:%02x.%x Error adding PCI capability "
1760                      "0x%x[0x%x]@0x%x: %d", vdev->host.domain,
1761                      vdev->host.bus, vdev->host.slot, vdev->host.function,
1762                      cap_id, size, pos, ret);
1763         return ret;
1764     }
1765 
1766     return 0;
1767 }
1768 
1769 static int vfio_add_capabilities(VFIOPCIDevice *vdev)
1770 {
1771     PCIDevice *pdev = &vdev->pdev;
1772 
1773     if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST) ||
1774         !pdev->config[PCI_CAPABILITY_LIST]) {
1775         return 0; /* Nothing to add */
1776     }
1777 
1778     return vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]);
1779 }
1780 
1781 static void vfio_pci_pre_reset(VFIOPCIDevice *vdev)
1782 {
1783     PCIDevice *pdev = &vdev->pdev;
1784     uint16_t cmd;
1785 
1786     vfio_disable_interrupts(vdev);
1787 
1788     /* Make sure the device is in D0 */
1789     if (vdev->pm_cap) {
1790         uint16_t pmcsr;
1791         uint8_t state;
1792 
1793         pmcsr = vfio_pci_read_config(pdev, vdev->pm_cap + PCI_PM_CTRL, 2);
1794         state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1795         if (state) {
1796             pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
1797             vfio_pci_write_config(pdev, vdev->pm_cap + PCI_PM_CTRL, pmcsr, 2);
1798             /* vfio handles the necessary delay here */
1799             pmcsr = vfio_pci_read_config(pdev, vdev->pm_cap + PCI_PM_CTRL, 2);
1800             state = pmcsr & PCI_PM_CTRL_STATE_MASK;
1801             if (state) {
1802                 error_report("vfio: Unable to power on device, stuck in D%d",
1803                              state);
1804             }
1805         }
1806     }
1807 
1808     /*
1809      * Stop any ongoing DMA by disconecting I/O, MMIO, and bus master.
1810      * Also put INTx Disable in known state.
1811      */
1812     cmd = vfio_pci_read_config(pdev, PCI_COMMAND, 2);
1813     cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
1814              PCI_COMMAND_INTX_DISABLE);
1815     vfio_pci_write_config(pdev, PCI_COMMAND, cmd, 2);
1816 }
1817 
1818 static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
1819 {
1820     vfio_intx_enable(vdev);
1821 }
1822 
1823 static bool vfio_pci_host_match(PCIHostDeviceAddress *host1,
1824                                 PCIHostDeviceAddress *host2)
1825 {
1826     return (host1->domain == host2->domain && host1->bus == host2->bus &&
1827             host1->slot == host2->slot && host1->function == host2->function);
1828 }
1829 
1830 static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
1831 {
1832     VFIOGroup *group;
1833     struct vfio_pci_hot_reset_info *info;
1834     struct vfio_pci_dependent_device *devices;
1835     struct vfio_pci_hot_reset *reset;
1836     int32_t *fds;
1837     int ret, i, count;
1838     bool multi = false;
1839 
1840     trace_vfio_pci_hot_reset(vdev->vbasedev.name, single ? "one" : "multi");
1841 
1842     vfio_pci_pre_reset(vdev);
1843     vdev->vbasedev.needs_reset = false;
1844 
1845     info = g_malloc0(sizeof(*info));
1846     info->argsz = sizeof(*info);
1847 
1848     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_PCI_HOT_RESET_INFO, info);
1849     if (ret && errno != ENOSPC) {
1850         ret = -errno;
1851         if (!vdev->has_pm_reset) {
1852             error_report("vfio: Cannot reset device %04x:%02x:%02x.%x, "
1853                          "no available reset mechanism.", vdev->host.domain,
1854                          vdev->host.bus, vdev->host.slot, vdev->host.function);
1855         }
1856         goto out_single;
1857     }
1858 
1859     count = info->count;
1860     info = g_realloc(info, sizeof(*info) + (count * sizeof(*devices)));
1861     info->argsz = sizeof(*info) + (count * sizeof(*devices));
1862     devices = &info->devices[0];
1863 
1864     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_PCI_HOT_RESET_INFO, info);
1865     if (ret) {
1866         ret = -errno;
1867         error_report("vfio: hot reset info failed: %m");
1868         goto out_single;
1869     }
1870 
1871     trace_vfio_pci_hot_reset_has_dep_devices(vdev->vbasedev.name);
1872 
1873     /* Verify that we have all the groups required */
1874     for (i = 0; i < info->count; i++) {
1875         PCIHostDeviceAddress host;
1876         VFIOPCIDevice *tmp;
1877         VFIODevice *vbasedev_iter;
1878 
1879         host.domain = devices[i].segment;
1880         host.bus = devices[i].bus;
1881         host.slot = PCI_SLOT(devices[i].devfn);
1882         host.function = PCI_FUNC(devices[i].devfn);
1883 
1884         trace_vfio_pci_hot_reset_dep_devices(host.domain,
1885                 host.bus, host.slot, host.function, devices[i].group_id);
1886 
1887         if (vfio_pci_host_match(&host, &vdev->host)) {
1888             continue;
1889         }
1890 
1891         QLIST_FOREACH(group, &vfio_group_list, next) {
1892             if (group->groupid == devices[i].group_id) {
1893                 break;
1894             }
1895         }
1896 
1897         if (!group) {
1898             if (!vdev->has_pm_reset) {
1899                 error_report("vfio: Cannot reset device %s, "
1900                              "depends on group %d which is not owned.",
1901                              vdev->vbasedev.name, devices[i].group_id);
1902             }
1903             ret = -EPERM;
1904             goto out;
1905         }
1906 
1907         /* Prep dependent devices for reset and clear our marker. */
1908         QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
1909             if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
1910                 continue;
1911             }
1912             tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
1913             if (vfio_pci_host_match(&host, &tmp->host)) {
1914                 if (single) {
1915                     ret = -EINVAL;
1916                     goto out_single;
1917                 }
1918                 vfio_pci_pre_reset(tmp);
1919                 tmp->vbasedev.needs_reset = false;
1920                 multi = true;
1921                 break;
1922             }
1923         }
1924     }
1925 
1926     if (!single && !multi) {
1927         ret = -EINVAL;
1928         goto out_single;
1929     }
1930 
1931     /* Determine how many group fds need to be passed */
1932     count = 0;
1933     QLIST_FOREACH(group, &vfio_group_list, next) {
1934         for (i = 0; i < info->count; i++) {
1935             if (group->groupid == devices[i].group_id) {
1936                 count++;
1937                 break;
1938             }
1939         }
1940     }
1941 
1942     reset = g_malloc0(sizeof(*reset) + (count * sizeof(*fds)));
1943     reset->argsz = sizeof(*reset) + (count * sizeof(*fds));
1944     fds = &reset->group_fds[0];
1945 
1946     /* Fill in group fds */
1947     QLIST_FOREACH(group, &vfio_group_list, next) {
1948         for (i = 0; i < info->count; i++) {
1949             if (group->groupid == devices[i].group_id) {
1950                 fds[reset->count++] = group->fd;
1951                 break;
1952             }
1953         }
1954     }
1955 
1956     /* Bus reset! */
1957     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_PCI_HOT_RESET, reset);
1958     g_free(reset);
1959 
1960     trace_vfio_pci_hot_reset_result(vdev->vbasedev.name,
1961                                     ret ? "%m" : "Success");
1962 
1963 out:
1964     /* Re-enable INTx on affected devices */
1965     for (i = 0; i < info->count; i++) {
1966         PCIHostDeviceAddress host;
1967         VFIOPCIDevice *tmp;
1968         VFIODevice *vbasedev_iter;
1969 
1970         host.domain = devices[i].segment;
1971         host.bus = devices[i].bus;
1972         host.slot = PCI_SLOT(devices[i].devfn);
1973         host.function = PCI_FUNC(devices[i].devfn);
1974 
1975         if (vfio_pci_host_match(&host, &vdev->host)) {
1976             continue;
1977         }
1978 
1979         QLIST_FOREACH(group, &vfio_group_list, next) {
1980             if (group->groupid == devices[i].group_id) {
1981                 break;
1982             }
1983         }
1984 
1985         if (!group) {
1986             break;
1987         }
1988 
1989         QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
1990             if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
1991                 continue;
1992             }
1993             tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
1994             if (vfio_pci_host_match(&host, &tmp->host)) {
1995                 vfio_pci_post_reset(tmp);
1996                 break;
1997             }
1998         }
1999     }
2000 out_single:
2001     vfio_pci_post_reset(vdev);
2002     g_free(info);
2003 
2004     return ret;
2005 }
2006 
2007 /*
2008  * We want to differentiate hot reset of mulitple in-use devices vs hot reset
2009  * of a single in-use device.  VFIO_DEVICE_RESET will already handle the case
2010  * of doing hot resets when there is only a single device per bus.  The in-use
2011  * here refers to how many VFIODevices are affected.  A hot reset that affects
2012  * multiple devices, but only a single in-use device, means that we can call
2013  * it from our bus ->reset() callback since the extent is effectively a single
2014  * device.  This allows us to make use of it in the hotplug path.  When there
2015  * are multiple in-use devices, we can only trigger the hot reset during a
2016  * system reset and thus from our reset handler.  We separate _one vs _multi
2017  * here so that we don't overlap and do a double reset on the system reset
2018  * path where both our reset handler and ->reset() callback are used.  Calling
2019  * _one() will only do a hot reset for the one in-use devices case, calling
2020  * _multi() will do nothing if a _one() would have been sufficient.
2021  */
2022 static int vfio_pci_hot_reset_one(VFIOPCIDevice *vdev)
2023 {
2024     return vfio_pci_hot_reset(vdev, true);
2025 }
2026 
2027 static int vfio_pci_hot_reset_multi(VFIODevice *vbasedev)
2028 {
2029     VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
2030     return vfio_pci_hot_reset(vdev, false);
2031 }
2032 
2033 static void vfio_pci_compute_needs_reset(VFIODevice *vbasedev)
2034 {
2035     VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
2036     if (!vbasedev->reset_works || (!vdev->has_flr && vdev->has_pm_reset)) {
2037         vbasedev->needs_reset = true;
2038     }
2039 }
2040 
2041 static VFIODeviceOps vfio_pci_ops = {
2042     .vfio_compute_needs_reset = vfio_pci_compute_needs_reset,
2043     .vfio_hot_reset_multi = vfio_pci_hot_reset_multi,
2044     .vfio_eoi = vfio_intx_eoi,
2045 };
2046 
2047 static int vfio_populate_device(VFIOPCIDevice *vdev)
2048 {
2049     VFIODevice *vbasedev = &vdev->vbasedev;
2050     struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
2051     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
2052     int i, ret = -1;
2053 
2054     /* Sanity check device */
2055     if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PCI)) {
2056         error_report("vfio: Um, this isn't a PCI device");
2057         goto error;
2058     }
2059 
2060     if (vbasedev->num_regions < VFIO_PCI_CONFIG_REGION_INDEX + 1) {
2061         error_report("vfio: unexpected number of io regions %u",
2062                      vbasedev->num_regions);
2063         goto error;
2064     }
2065 
2066     if (vbasedev->num_irqs < VFIO_PCI_MSIX_IRQ_INDEX + 1) {
2067         error_report("vfio: unexpected number of irqs %u", vbasedev->num_irqs);
2068         goto error;
2069     }
2070 
2071     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
2072         reg_info.index = i;
2073 
2074         ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
2075         if (ret) {
2076             error_report("vfio: Error getting region %d info: %m", i);
2077             goto error;
2078         }
2079 
2080         trace_vfio_populate_device_region(vbasedev->name, i,
2081                                           (unsigned long)reg_info.size,
2082                                           (unsigned long)reg_info.offset,
2083                                           (unsigned long)reg_info.flags);
2084 
2085         vdev->bars[i].region.vbasedev = vbasedev;
2086         vdev->bars[i].region.flags = reg_info.flags;
2087         vdev->bars[i].region.size = reg_info.size;
2088         vdev->bars[i].region.fd_offset = reg_info.offset;
2089         vdev->bars[i].region.nr = i;
2090         QLIST_INIT(&vdev->bars[i].quirks);
2091     }
2092 
2093     reg_info.index = VFIO_PCI_CONFIG_REGION_INDEX;
2094 
2095     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
2096     if (ret) {
2097         error_report("vfio: Error getting config info: %m");
2098         goto error;
2099     }
2100 
2101     trace_vfio_populate_device_config(vdev->vbasedev.name,
2102                                       (unsigned long)reg_info.size,
2103                                       (unsigned long)reg_info.offset,
2104                                       (unsigned long)reg_info.flags);
2105 
2106     vdev->config_size = reg_info.size;
2107     if (vdev->config_size == PCI_CONFIG_SPACE_SIZE) {
2108         vdev->pdev.cap_present &= ~QEMU_PCI_CAP_EXPRESS;
2109     }
2110     vdev->config_offset = reg_info.offset;
2111 
2112     if ((vdev->features & VFIO_FEATURE_ENABLE_VGA) &&
2113         vbasedev->num_regions > VFIO_PCI_VGA_REGION_INDEX) {
2114         struct vfio_region_info vga_info = {
2115             .argsz = sizeof(vga_info),
2116             .index = VFIO_PCI_VGA_REGION_INDEX,
2117          };
2118 
2119         ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &vga_info);
2120         if (ret) {
2121             error_report(
2122                 "vfio: Device does not support requested feature x-vga");
2123             goto error;
2124         }
2125 
2126         if (!(vga_info.flags & VFIO_REGION_INFO_FLAG_READ) ||
2127             !(vga_info.flags & VFIO_REGION_INFO_FLAG_WRITE) ||
2128             vga_info.size < 0xbffff + 1) {
2129             error_report("vfio: Unexpected VGA info, flags 0x%lx, size 0x%lx",
2130                          (unsigned long)vga_info.flags,
2131                          (unsigned long)vga_info.size);
2132             goto error;
2133         }
2134 
2135         vdev->vga.fd_offset = vga_info.offset;
2136         vdev->vga.fd = vdev->vbasedev.fd;
2137 
2138         vdev->vga.region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
2139         vdev->vga.region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
2140         QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_MEM].quirks);
2141 
2142         vdev->vga.region[QEMU_PCI_VGA_IO_LO].offset = QEMU_PCI_VGA_IO_LO_BASE;
2143         vdev->vga.region[QEMU_PCI_VGA_IO_LO].nr = QEMU_PCI_VGA_IO_LO;
2144         QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_IO_LO].quirks);
2145 
2146         vdev->vga.region[QEMU_PCI_VGA_IO_HI].offset = QEMU_PCI_VGA_IO_HI_BASE;
2147         vdev->vga.region[QEMU_PCI_VGA_IO_HI].nr = QEMU_PCI_VGA_IO_HI;
2148         QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].quirks);
2149 
2150         vdev->has_vga = true;
2151     }
2152 
2153     irq_info.index = VFIO_PCI_ERR_IRQ_INDEX;
2154 
2155     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
2156     if (ret) {
2157         /* This can fail for an old kernel or legacy PCI dev */
2158         trace_vfio_populate_device_get_irq_info_failure();
2159         ret = 0;
2160     } else if (irq_info.count == 1) {
2161         vdev->pci_aer = true;
2162     } else {
2163         error_report("vfio: %s "
2164                      "Could not enable error recovery for the device",
2165                      vbasedev->name);
2166     }
2167 
2168 error:
2169     return ret;
2170 }
2171 
2172 static void vfio_put_device(VFIOPCIDevice *vdev)
2173 {
2174     g_free(vdev->vbasedev.name);
2175     if (vdev->msix) {
2176         object_unparent(OBJECT(&vdev->msix->mmap_mem));
2177         g_free(vdev->msix);
2178         vdev->msix = NULL;
2179     }
2180     vfio_put_base_device(&vdev->vbasedev);
2181 }
2182 
2183 static void vfio_err_notifier_handler(void *opaque)
2184 {
2185     VFIOPCIDevice *vdev = opaque;
2186 
2187     if (!event_notifier_test_and_clear(&vdev->err_notifier)) {
2188         return;
2189     }
2190 
2191     /*
2192      * TBD. Retrieve the error details and decide what action
2193      * needs to be taken. One of the actions could be to pass
2194      * the error to the guest and have the guest driver recover
2195      * from the error. This requires that PCIe capabilities be
2196      * exposed to the guest. For now, we just terminate the
2197      * guest to contain the error.
2198      */
2199 
2200     error_report("%s(%04x:%02x:%02x.%x) Unrecoverable error detected.  "
2201                  "Please collect any data possible and then kill the guest",
2202                  __func__, vdev->host.domain, vdev->host.bus,
2203                  vdev->host.slot, vdev->host.function);
2204 
2205     vm_stop(RUN_STATE_INTERNAL_ERROR);
2206 }
2207 
2208 /*
2209  * Registers error notifier for devices supporting error recovery.
2210  * If we encounter a failure in this function, we report an error
2211  * and continue after disabling error recovery support for the
2212  * device.
2213  */
2214 static void vfio_register_err_notifier(VFIOPCIDevice *vdev)
2215 {
2216     int ret;
2217     int argsz;
2218     struct vfio_irq_set *irq_set;
2219     int32_t *pfd;
2220 
2221     if (!vdev->pci_aer) {
2222         return;
2223     }
2224 
2225     if (event_notifier_init(&vdev->err_notifier, 0)) {
2226         error_report("vfio: Unable to init event notifier for error detection");
2227         vdev->pci_aer = false;
2228         return;
2229     }
2230 
2231     argsz = sizeof(*irq_set) + sizeof(*pfd);
2232 
2233     irq_set = g_malloc0(argsz);
2234     irq_set->argsz = argsz;
2235     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
2236                      VFIO_IRQ_SET_ACTION_TRIGGER;
2237     irq_set->index = VFIO_PCI_ERR_IRQ_INDEX;
2238     irq_set->start = 0;
2239     irq_set->count = 1;
2240     pfd = (int32_t *)&irq_set->data;
2241 
2242     *pfd = event_notifier_get_fd(&vdev->err_notifier);
2243     qemu_set_fd_handler(*pfd, vfio_err_notifier_handler, NULL, vdev);
2244 
2245     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
2246     if (ret) {
2247         error_report("vfio: Failed to set up error notification");
2248         qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
2249         event_notifier_cleanup(&vdev->err_notifier);
2250         vdev->pci_aer = false;
2251     }
2252     g_free(irq_set);
2253 }
2254 
2255 static void vfio_unregister_err_notifier(VFIOPCIDevice *vdev)
2256 {
2257     int argsz;
2258     struct vfio_irq_set *irq_set;
2259     int32_t *pfd;
2260     int ret;
2261 
2262     if (!vdev->pci_aer) {
2263         return;
2264     }
2265 
2266     argsz = sizeof(*irq_set) + sizeof(*pfd);
2267 
2268     irq_set = g_malloc0(argsz);
2269     irq_set->argsz = argsz;
2270     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
2271                      VFIO_IRQ_SET_ACTION_TRIGGER;
2272     irq_set->index = VFIO_PCI_ERR_IRQ_INDEX;
2273     irq_set->start = 0;
2274     irq_set->count = 1;
2275     pfd = (int32_t *)&irq_set->data;
2276     *pfd = -1;
2277 
2278     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
2279     if (ret) {
2280         error_report("vfio: Failed to de-assign error fd: %m");
2281     }
2282     g_free(irq_set);
2283     qemu_set_fd_handler(event_notifier_get_fd(&vdev->err_notifier),
2284                         NULL, NULL, vdev);
2285     event_notifier_cleanup(&vdev->err_notifier);
2286 }
2287 
2288 static void vfio_req_notifier_handler(void *opaque)
2289 {
2290     VFIOPCIDevice *vdev = opaque;
2291 
2292     if (!event_notifier_test_and_clear(&vdev->req_notifier)) {
2293         return;
2294     }
2295 
2296     qdev_unplug(&vdev->pdev.qdev, NULL);
2297 }
2298 
2299 static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
2300 {
2301     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
2302                                       .index = VFIO_PCI_REQ_IRQ_INDEX };
2303     int argsz;
2304     struct vfio_irq_set *irq_set;
2305     int32_t *pfd;
2306 
2307     if (!(vdev->features & VFIO_FEATURE_ENABLE_REQ)) {
2308         return;
2309     }
2310 
2311     if (ioctl(vdev->vbasedev.fd,
2312               VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) {
2313         return;
2314     }
2315 
2316     if (event_notifier_init(&vdev->req_notifier, 0)) {
2317         error_report("vfio: Unable to init event notifier for device request");
2318         return;
2319     }
2320 
2321     argsz = sizeof(*irq_set) + sizeof(*pfd);
2322 
2323     irq_set = g_malloc0(argsz);
2324     irq_set->argsz = argsz;
2325     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
2326                      VFIO_IRQ_SET_ACTION_TRIGGER;
2327     irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
2328     irq_set->start = 0;
2329     irq_set->count = 1;
2330     pfd = (int32_t *)&irq_set->data;
2331 
2332     *pfd = event_notifier_get_fd(&vdev->req_notifier);
2333     qemu_set_fd_handler(*pfd, vfio_req_notifier_handler, NULL, vdev);
2334 
2335     if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
2336         error_report("vfio: Failed to set up device request notification");
2337         qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
2338         event_notifier_cleanup(&vdev->req_notifier);
2339     } else {
2340         vdev->req_enabled = true;
2341     }
2342 
2343     g_free(irq_set);
2344 }
2345 
2346 static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev)
2347 {
2348     int argsz;
2349     struct vfio_irq_set *irq_set;
2350     int32_t *pfd;
2351 
2352     if (!vdev->req_enabled) {
2353         return;
2354     }
2355 
2356     argsz = sizeof(*irq_set) + sizeof(*pfd);
2357 
2358     irq_set = g_malloc0(argsz);
2359     irq_set->argsz = argsz;
2360     irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
2361                      VFIO_IRQ_SET_ACTION_TRIGGER;
2362     irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
2363     irq_set->start = 0;
2364     irq_set->count = 1;
2365     pfd = (int32_t *)&irq_set->data;
2366     *pfd = -1;
2367 
2368     if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
2369         error_report("vfio: Failed to de-assign device request fd: %m");
2370     }
2371     g_free(irq_set);
2372     qemu_set_fd_handler(event_notifier_get_fd(&vdev->req_notifier),
2373                         NULL, NULL, vdev);
2374     event_notifier_cleanup(&vdev->req_notifier);
2375 
2376     vdev->req_enabled = false;
2377 }
2378 
2379 static int vfio_initfn(PCIDevice *pdev)
2380 {
2381     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
2382     VFIODevice *vbasedev_iter;
2383     VFIOGroup *group;
2384     char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
2385     ssize_t len;
2386     struct stat st;
2387     int groupid;
2388     int ret;
2389 
2390     /* Check that the host device exists */
2391     snprintf(path, sizeof(path),
2392              "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/",
2393              vdev->host.domain, vdev->host.bus, vdev->host.slot,
2394              vdev->host.function);
2395     if (stat(path, &st) < 0) {
2396         error_report("vfio: error: no such host device: %s", path);
2397         return -errno;
2398     }
2399 
2400     vdev->vbasedev.ops = &vfio_pci_ops;
2401 
2402     vdev->vbasedev.type = VFIO_DEVICE_TYPE_PCI;
2403     vdev->vbasedev.name = g_strdup_printf("%04x:%02x:%02x.%01x",
2404                                           vdev->host.domain, vdev->host.bus,
2405                                           vdev->host.slot, vdev->host.function);
2406 
2407     strncat(path, "iommu_group", sizeof(path) - strlen(path) - 1);
2408 
2409     len = readlink(path, iommu_group_path, sizeof(path));
2410     if (len <= 0 || len >= sizeof(path)) {
2411         error_report("vfio: error no iommu_group for device");
2412         return len < 0 ? -errno : -ENAMETOOLONG;
2413     }
2414 
2415     iommu_group_path[len] = 0;
2416     group_name = basename(iommu_group_path);
2417 
2418     if (sscanf(group_name, "%d", &groupid) != 1) {
2419         error_report("vfio: error reading %s: %m", path);
2420         return -errno;
2421     }
2422 
2423     trace_vfio_initfn(vdev->vbasedev.name, groupid);
2424 
2425     group = vfio_get_group(groupid, pci_device_iommu_address_space(pdev));
2426     if (!group) {
2427         error_report("vfio: failed to get group %d", groupid);
2428         return -ENOENT;
2429     }
2430 
2431     snprintf(path, sizeof(path), "%04x:%02x:%02x.%01x",
2432             vdev->host.domain, vdev->host.bus, vdev->host.slot,
2433             vdev->host.function);
2434 
2435     QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
2436         if (strcmp(vbasedev_iter->name, vdev->vbasedev.name) == 0) {
2437             error_report("vfio: error: device %s is already attached", path);
2438             vfio_put_group(group);
2439             return -EBUSY;
2440         }
2441     }
2442 
2443     ret = vfio_get_device(group, path, &vdev->vbasedev);
2444     if (ret) {
2445         error_report("vfio: failed to get device %s", path);
2446         vfio_put_group(group);
2447         return ret;
2448     }
2449 
2450     ret = vfio_populate_device(vdev);
2451     if (ret) {
2452         return ret;
2453     }
2454 
2455     /* Get a copy of config space */
2456     ret = pread(vdev->vbasedev.fd, vdev->pdev.config,
2457                 MIN(pci_config_size(&vdev->pdev), vdev->config_size),
2458                 vdev->config_offset);
2459     if (ret < (int)MIN(pci_config_size(&vdev->pdev), vdev->config_size)) {
2460         ret = ret < 0 ? -errno : -EFAULT;
2461         error_report("vfio: Failed to read device config space");
2462         return ret;
2463     }
2464 
2465     /* vfio emulates a lot for us, but some bits need extra love */
2466     vdev->emulated_config_bits = g_malloc0(vdev->config_size);
2467 
2468     /* QEMU can choose to expose the ROM or not */
2469     memset(vdev->emulated_config_bits + PCI_ROM_ADDRESS, 0xff, 4);
2470 
2471     /*
2472      * The PCI spec reserves vendor ID 0xffff as an invalid value.  The
2473      * device ID is managed by the vendor and need only be a 16-bit value.
2474      * Allow any 16-bit value for subsystem so they can be hidden or changed.
2475      */
2476     if (vdev->vendor_id != PCI_ANY_ID) {
2477         if (vdev->vendor_id >= 0xffff) {
2478             error_report("vfio: Invalid PCI vendor ID provided");
2479             return -EINVAL;
2480         }
2481         vfio_add_emulated_word(vdev, PCI_VENDOR_ID, vdev->vendor_id, ~0);
2482         trace_vfio_pci_emulated_vendor_id(vdev->vbasedev.name, vdev->vendor_id);
2483     } else {
2484         vdev->vendor_id = pci_get_word(pdev->config + PCI_VENDOR_ID);
2485     }
2486 
2487     if (vdev->device_id != PCI_ANY_ID) {
2488         if (vdev->device_id > 0xffff) {
2489             error_report("vfio: Invalid PCI device ID provided");
2490             return -EINVAL;
2491         }
2492         vfio_add_emulated_word(vdev, PCI_DEVICE_ID, vdev->device_id, ~0);
2493         trace_vfio_pci_emulated_device_id(vdev->vbasedev.name, vdev->device_id);
2494     } else {
2495         vdev->device_id = pci_get_word(pdev->config + PCI_DEVICE_ID);
2496     }
2497 
2498     if (vdev->sub_vendor_id != PCI_ANY_ID) {
2499         if (vdev->sub_vendor_id > 0xffff) {
2500             error_report("vfio: Invalid PCI subsystem vendor ID provided");
2501             return -EINVAL;
2502         }
2503         vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_VENDOR_ID,
2504                                vdev->sub_vendor_id, ~0);
2505         trace_vfio_pci_emulated_sub_vendor_id(vdev->vbasedev.name,
2506                                               vdev->sub_vendor_id);
2507     }
2508 
2509     if (vdev->sub_device_id != PCI_ANY_ID) {
2510         if (vdev->sub_device_id > 0xffff) {
2511             error_report("vfio: Invalid PCI subsystem device ID provided");
2512             return -EINVAL;
2513         }
2514         vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_ID, vdev->sub_device_id, ~0);
2515         trace_vfio_pci_emulated_sub_device_id(vdev->vbasedev.name,
2516                                               vdev->sub_device_id);
2517     }
2518 
2519     /* QEMU can change multi-function devices to single function, or reverse */
2520     vdev->emulated_config_bits[PCI_HEADER_TYPE] =
2521                                               PCI_HEADER_TYPE_MULTI_FUNCTION;
2522 
2523     /* Restore or clear multifunction, this is always controlled by QEMU */
2524     if (vdev->pdev.cap_present & QEMU_PCI_CAP_MULTIFUNCTION) {
2525         vdev->pdev.config[PCI_HEADER_TYPE] |= PCI_HEADER_TYPE_MULTI_FUNCTION;
2526     } else {
2527         vdev->pdev.config[PCI_HEADER_TYPE] &= ~PCI_HEADER_TYPE_MULTI_FUNCTION;
2528     }
2529 
2530     /*
2531      * Clear host resource mapping info.  If we choose not to register a
2532      * BAR, such as might be the case with the option ROM, we can get
2533      * confusing, unwritable, residual addresses from the host here.
2534      */
2535     memset(&vdev->pdev.config[PCI_BASE_ADDRESS_0], 0, 24);
2536     memset(&vdev->pdev.config[PCI_ROM_ADDRESS], 0, 4);
2537 
2538     vfio_pci_size_rom(vdev);
2539 
2540     ret = vfio_msix_early_setup(vdev);
2541     if (ret) {
2542         return ret;
2543     }
2544 
2545     vfio_map_bars(vdev);
2546 
2547     ret = vfio_add_capabilities(vdev);
2548     if (ret) {
2549         goto out_teardown;
2550     }
2551 
2552     /* QEMU emulates all of MSI & MSIX */
2553     if (pdev->cap_present & QEMU_PCI_CAP_MSIX) {
2554         memset(vdev->emulated_config_bits + pdev->msix_cap, 0xff,
2555                MSIX_CAP_LENGTH);
2556     }
2557 
2558     if (pdev->cap_present & QEMU_PCI_CAP_MSI) {
2559         memset(vdev->emulated_config_bits + pdev->msi_cap, 0xff,
2560                vdev->msi_cap_size);
2561     }
2562 
2563     if (vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1)) {
2564         vdev->intx.mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
2565                                                   vfio_intx_mmap_enable, vdev);
2566         pci_device_set_intx_routing_notifier(&vdev->pdev, vfio_intx_update);
2567         ret = vfio_intx_enable(vdev);
2568         if (ret) {
2569             goto out_teardown;
2570         }
2571     }
2572 
2573     vfio_register_err_notifier(vdev);
2574     vfio_register_req_notifier(vdev);
2575     vfio_setup_resetfn_quirk(vdev);
2576 
2577     return 0;
2578 
2579 out_teardown:
2580     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
2581     vfio_teardown_msi(vdev);
2582     vfio_unregister_bars(vdev);
2583     return ret;
2584 }
2585 
2586 static void vfio_instance_finalize(Object *obj)
2587 {
2588     PCIDevice *pci_dev = PCI_DEVICE(obj);
2589     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pci_dev);
2590     VFIOGroup *group = vdev->vbasedev.group;
2591 
2592     vfio_unmap_bars(vdev);
2593     g_free(vdev->emulated_config_bits);
2594     g_free(vdev->rom);
2595     vfio_put_device(vdev);
2596     vfio_put_group(group);
2597 }
2598 
2599 static void vfio_exitfn(PCIDevice *pdev)
2600 {
2601     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
2602 
2603     vfio_unregister_req_notifier(vdev);
2604     vfio_unregister_err_notifier(vdev);
2605     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
2606     vfio_disable_interrupts(vdev);
2607     if (vdev->intx.mmap_timer) {
2608         timer_free(vdev->intx.mmap_timer);
2609     }
2610     vfio_teardown_msi(vdev);
2611     vfio_unregister_bars(vdev);
2612 }
2613 
2614 static void vfio_pci_reset(DeviceState *dev)
2615 {
2616     PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, dev);
2617     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
2618 
2619     trace_vfio_pci_reset(vdev->vbasedev.name);
2620 
2621     vfio_pci_pre_reset(vdev);
2622 
2623     if (vdev->resetfn && !vdev->resetfn(vdev)) {
2624         goto post_reset;
2625     }
2626 
2627     if (vdev->vbasedev.reset_works &&
2628         (vdev->has_flr || !vdev->has_pm_reset) &&
2629         !ioctl(vdev->vbasedev.fd, VFIO_DEVICE_RESET)) {
2630         trace_vfio_pci_reset_flr(vdev->vbasedev.name);
2631         goto post_reset;
2632     }
2633 
2634     /* See if we can do our own bus reset */
2635     if (!vfio_pci_hot_reset_one(vdev)) {
2636         goto post_reset;
2637     }
2638 
2639     /* If nothing else works and the device supports PM reset, use it */
2640     if (vdev->vbasedev.reset_works && vdev->has_pm_reset &&
2641         !ioctl(vdev->vbasedev.fd, VFIO_DEVICE_RESET)) {
2642         trace_vfio_pci_reset_pm(vdev->vbasedev.name);
2643         goto post_reset;
2644     }
2645 
2646 post_reset:
2647     vfio_pci_post_reset(vdev);
2648 }
2649 
2650 static void vfio_instance_init(Object *obj)
2651 {
2652     PCIDevice *pci_dev = PCI_DEVICE(obj);
2653     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, PCI_DEVICE(obj));
2654 
2655     device_add_bootindex_property(obj, &vdev->bootindex,
2656                                   "bootindex", NULL,
2657                                   &pci_dev->qdev, NULL);
2658 }
2659 
2660 static Property vfio_pci_dev_properties[] = {
2661     DEFINE_PROP_PCI_HOST_DEVADDR("host", VFIOPCIDevice, host),
2662     DEFINE_PROP_UINT32("x-intx-mmap-timeout-ms", VFIOPCIDevice,
2663                        intx.mmap_timeout, 1100),
2664     DEFINE_PROP_BIT("x-vga", VFIOPCIDevice, features,
2665                     VFIO_FEATURE_ENABLE_VGA_BIT, false),
2666     DEFINE_PROP_BIT("x-req", VFIOPCIDevice, features,
2667                     VFIO_FEATURE_ENABLE_REQ_BIT, true),
2668     DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false),
2669     DEFINE_PROP_BOOL("x-no-kvm-intx", VFIOPCIDevice, no_kvm_intx, false),
2670     DEFINE_PROP_BOOL("x-no-kvm-msi", VFIOPCIDevice, no_kvm_msi, false),
2671     DEFINE_PROP_BOOL("x-no-kvm-msix", VFIOPCIDevice, no_kvm_msix, false),
2672     DEFINE_PROP_UINT32("x-pci-vendor-id", VFIOPCIDevice, vendor_id, PCI_ANY_ID),
2673     DEFINE_PROP_UINT32("x-pci-device-id", VFIOPCIDevice, device_id, PCI_ANY_ID),
2674     DEFINE_PROP_UINT32("x-pci-sub-vendor-id", VFIOPCIDevice,
2675                        sub_vendor_id, PCI_ANY_ID),
2676     DEFINE_PROP_UINT32("x-pci-sub-device-id", VFIOPCIDevice,
2677                        sub_device_id, PCI_ANY_ID),
2678     /*
2679      * TODO - support passed fds... is this necessary?
2680      * DEFINE_PROP_STRING("vfiofd", VFIOPCIDevice, vfiofd_name),
2681      * DEFINE_PROP_STRING("vfiogroupfd, VFIOPCIDevice, vfiogroupfd_name),
2682      */
2683     DEFINE_PROP_END_OF_LIST(),
2684 };
2685 
2686 static const VMStateDescription vfio_pci_vmstate = {
2687     .name = "vfio-pci",
2688     .unmigratable = 1,
2689 };
2690 
2691 static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
2692 {
2693     DeviceClass *dc = DEVICE_CLASS(klass);
2694     PCIDeviceClass *pdc = PCI_DEVICE_CLASS(klass);
2695 
2696     dc->reset = vfio_pci_reset;
2697     dc->props = vfio_pci_dev_properties;
2698     dc->vmsd = &vfio_pci_vmstate;
2699     dc->desc = "VFIO-based PCI device assignment";
2700     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
2701     pdc->init = vfio_initfn;
2702     pdc->exit = vfio_exitfn;
2703     pdc->config_read = vfio_pci_read_config;
2704     pdc->config_write = vfio_pci_write_config;
2705     pdc->is_express = 1; /* We might be */
2706 }
2707 
2708 static const TypeInfo vfio_pci_dev_info = {
2709     .name = "vfio-pci",
2710     .parent = TYPE_PCI_DEVICE,
2711     .instance_size = sizeof(VFIOPCIDevice),
2712     .class_init = vfio_pci_dev_class_init,
2713     .instance_init = vfio_instance_init,
2714     .instance_finalize = vfio_instance_finalize,
2715 };
2716 
2717 static void register_vfio_pci_dev_type(void)
2718 {
2719     type_register_static(&vfio_pci_dev_info);
2720 }
2721 
2722 type_init(register_vfio_pci_dev_type)
2723