1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
3 #define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
4 /*
5 * Virtio PCI driver - APIs for common functionality for all device versions
6 *
7 * This module allows virtio devices to be used over a virtual PCI device.
8 * This can be used with QEMU based VMMs like KVM or Xen.
9 *
10 * Copyright IBM Corp. 2007
11 * Copyright Red Hat, Inc. 2014
12 *
13 * Authors:
14 * Anthony Liguori <aliguori@us.ibm.com>
15 * Rusty Russell <rusty@rustcorp.com.au>
16 * Michael S. Tsirkin <mst@redhat.com>
17 */
18
19 #include <linux/module.h>
20 #include <linux/list.h>
21 #include <linux/pci.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/virtio.h>
25 #include <linux/virtio_config.h>
26 #include <linux/virtio_ring.h>
27 #include <linux/virtio_pci.h>
28 #include <linux/virtio_pci_legacy.h>
29 #include <linux/virtio_pci_modern.h>
30 #include <linux/highmem.h>
31 #include <linux/spinlock.h>
32 #include <linux/mutex.h>
33
34 struct virtio_pci_vq_info {
35 /* the actual virtqueue */
36 struct virtqueue *vq;
37
38 /* the list node for the virtqueues list */
39 struct list_head node;
40
41 /* MSI-X vector (or none) */
42 unsigned int msix_vector;
43 };
44
45 struct virtio_pci_admin_vq {
46 /* Virtqueue info associated with this admin queue. */
47 struct virtio_pci_vq_info info;
48 /* serializing admin commands execution and virtqueue deletion */
49 struct mutex cmd_lock;
50 u64 supported_cmds;
51 /* Name of the admin queue: avq.$vq_index. */
52 char name[10];
53 u16 vq_index;
54 };
55
56 /* Our device structure */
57 struct virtio_pci_device {
58 struct virtio_device vdev;
59 struct pci_dev *pci_dev;
60 union {
61 struct virtio_pci_legacy_device ldev;
62 struct virtio_pci_modern_device mdev;
63 };
64 bool is_legacy;
65
66 /* Where to read and clear interrupt */
67 u8 __iomem *isr;
68
69 /* a list of queues so we can dispatch IRQs */
70 spinlock_t lock;
71 struct list_head virtqueues;
72
73 /* Array of all virtqueues reported in the
74 * PCI common config num_queues field
75 */
76 struct virtio_pci_vq_info **vqs;
77
78 struct virtio_pci_admin_vq admin_vq;
79
80 /* MSI-X support */
81 int msix_enabled;
82 int intx_enabled;
83 cpumask_var_t *msix_affinity_masks;
84 /* Name strings for interrupts. This size should be enough,
85 * and I'm too lazy to allocate each name separately. */
86 char (*msix_names)[256];
87 /* Number of available vectors */
88 unsigned int msix_vectors;
89 /* Vectors allocated, excluding per-vq vectors if any */
90 unsigned int msix_used_vectors;
91
92 /* Whether we have vector per vq */
93 bool per_vq_vectors;
94
95 struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
96 struct virtio_pci_vq_info *info,
97 unsigned int idx,
98 void (*callback)(struct virtqueue *vq),
99 const char *name,
100 bool ctx,
101 u16 msix_vec);
102 void (*del_vq)(struct virtio_pci_vq_info *info);
103
104 u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
105 bool (*is_avq)(struct virtio_device *vdev, unsigned int index);
106 };
107
108 /* Constants for MSI-X */
109 /* Use first vector for configuration changes, second and the rest for
110 * virtqueues Thus, we need at least 2 vectors for MSI. */
111 enum {
112 VP_MSIX_CONFIG_VECTOR = 0,
113 VP_MSIX_VQ_VECTOR = 1,
114 };
115
116 /* Convert a generic virtio device to our structure */
to_vp_device(struct virtio_device * vdev)117 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
118 {
119 return container_of(vdev, struct virtio_pci_device, vdev);
120 }
121
122 /* wait for pending irq handlers */
123 void vp_synchronize_vectors(struct virtio_device *vdev);
124 /* the notify function used when creating a virt queue */
125 bool vp_notify(struct virtqueue *vq);
126 /* the config->del_vqs() implementation */
127 void vp_del_vqs(struct virtio_device *vdev);
128 /* the config->find_vqs() implementation */
129 int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
130 struct virtqueue *vqs[], vq_callback_t *callbacks[],
131 const char * const names[], const bool *ctx,
132 struct irq_affinity *desc);
133 const char *vp_bus_name(struct virtio_device *vdev);
134
135 /* Setup the affinity for a virtqueue:
136 * - force the affinity for per vq vector
137 * - OR over all affinities for shared MSI
138 * - ignore the affinity request if we're using INTX
139 */
140 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
141
142 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
143
144 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
145 int virtio_pci_legacy_probe(struct virtio_pci_device *);
146 void virtio_pci_legacy_remove(struct virtio_pci_device *);
147 #else
virtio_pci_legacy_probe(struct virtio_pci_device * vp_dev)148 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
149 {
150 return -ENODEV;
151 }
virtio_pci_legacy_remove(struct virtio_pci_device * vp_dev)152 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
153 {
154 }
155 #endif
156 int virtio_pci_modern_probe(struct virtio_pci_device *);
157 void virtio_pci_modern_remove(struct virtio_pci_device *);
158
159 struct virtio_device *virtio_pci_vf_get_pf_dev(struct pci_dev *pdev);
160
161 #define VIRTIO_LEGACY_ADMIN_CMD_BITMAP \
162 (BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE) | \
163 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ) | \
164 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE) | \
165 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ) | \
166 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO))
167
168 /* Unlike modern drivers which support hardware virtio devices, legacy drivers
169 * assume software-based devices: e.g. they don't use proper memory barriers
170 * on ARM, use big endian on PPC, etc. X86 drivers are mostly ok though, more
171 * or less by chance. For now, only support legacy IO on X86.
172 */
173 #ifdef CONFIG_VIRTIO_PCI_ADMIN_LEGACY
174 #define VIRTIO_ADMIN_CMD_BITMAP VIRTIO_LEGACY_ADMIN_CMD_BITMAP
175 #else
176 #define VIRTIO_ADMIN_CMD_BITMAP 0
177 #endif
178
179 int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
180 struct virtio_admin_cmd *cmd);
181
182 #endif
183