xref: /qemu/hw/remote/iohub.c (revision de11da64)
1 /*
2  * Remote IO Hub
3  *
4  * Copyright © 2018, 2021 Oracle and/or its affiliates.
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  *
9  */
10 
11 #include "qemu/osdep.h"
12 
13 #include "hw/pci/pci.h"
14 #include "hw/pci/pci_ids.h"
15 #include "hw/pci/pci_bus.h"
16 #include "qemu/thread.h"
17 #include "hw/remote/machine.h"
18 #include "hw/remote/iohub.h"
19 #include "qemu/main-loop.h"
20 
21 void remote_iohub_init(RemoteIOHubState *iohub)
22 {
23     int pirq;
24 
25     memset(&iohub->irqfds, 0, sizeof(iohub->irqfds));
26     memset(&iohub->resamplefds, 0, sizeof(iohub->resamplefds));
27 
28     for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
29         qemu_mutex_init(&iohub->irq_level_lock[pirq]);
30         iohub->irq_level[pirq] = 0;
31         event_notifier_init_fd(&iohub->irqfds[pirq], -1);
32         event_notifier_init_fd(&iohub->resamplefds[pirq], -1);
33     }
34 }
35 
36 int remote_iohub_map_irq(PCIDevice *pci_dev, int intx)
37 {
38     return pci_dev->devfn;
39 }
40 
41 void remote_iohub_set_irq(void *opaque, int pirq, int level)
42 {
43     RemoteIOHubState *iohub = opaque;
44 
45     assert(pirq >= 0);
46     assert(pirq < PCI_DEVFN_MAX);
47 
48     QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
49 
50     if (level) {
51         if (++iohub->irq_level[pirq] == 1) {
52             event_notifier_set(&iohub->irqfds[pirq]);
53         }
54     } else if (iohub->irq_level[pirq] > 0) {
55         iohub->irq_level[pirq]--;
56     }
57 }
58 
59 static void intr_resample_handler(void *opaque)
60 {
61     ResampleToken *token = opaque;
62     RemoteIOHubState *iohub = token->iohub;
63     int pirq, s;
64 
65     pirq = token->pirq;
66 
67     s = event_notifier_test_and_clear(&iohub->resamplefds[pirq]);
68 
69     assert(s >= 0);
70 
71     QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
72 
73     if (iohub->irq_level[pirq]) {
74         event_notifier_set(&iohub->irqfds[pirq]);
75     }
76 }
77 
78 void process_set_irqfd_msg(PCIDevice *pci_dev, MPQemuMsg *msg)
79 {
80     RemoteMachineState *machine = REMOTE_MACHINE(current_machine);
81     RemoteIOHubState *iohub = &machine->iohub;
82     int pirq, intx;
83 
84     intx = pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1;
85 
86     pirq = remote_iohub_map_irq(pci_dev, intx);
87 
88     if (event_notifier_get_fd(&iohub->irqfds[pirq]) != -1) {
89         qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
90                             NULL, NULL, NULL);
91         event_notifier_cleanup(&iohub->irqfds[pirq]);
92         event_notifier_cleanup(&iohub->resamplefds[pirq]);
93         memset(&iohub->token[pirq], 0, sizeof(ResampleToken));
94     }
95 
96     event_notifier_init_fd(&iohub->irqfds[pirq], msg->fds[0]);
97     event_notifier_init_fd(&iohub->resamplefds[pirq], msg->fds[1]);
98 
99     iohub->token[pirq].iohub = iohub;
100     iohub->token[pirq].pirq = pirq;
101 
102     qemu_set_fd_handler(msg->fds[1], intr_resample_handler, NULL,
103                         &iohub->token[pirq]);
104 }
105