drivers/virtio/virtio_pci_common.h

   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 or slow_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         /* Protects virtqueue access. */
  49         spinlock_t lock;
  50         u64 supported_cmds;
  51         u64 supported_caps;
  52         u8 max_dev_parts_objects;
  53         struct ida dev_parts_ida;
  54         /* Name of the admin queue: avq.$vq_index. */
  55         char name[10];
  56         u16 vq_index;
  57 };
  58
  59 /* Our device structure */
  60 struct virtio_pci_device {
  61         struct virtio_device vdev;
  62         struct pci_dev *pci_dev;
  63         union {
  64                 struct virtio_pci_legacy_device ldev;
  65                 struct virtio_pci_modern_device mdev;
  66         };
  67         bool is_legacy;
  68
  69         /* Where to read and clear interrupt */
  70         u8 __iomem *isr;
  71
  72         /* Lists of queues and potentially slow path queues
  73          * so we can dispatch IRQs.
  74          */
  75         spinlock_t lock;
  76         struct list_head virtqueues;
  77         struct list_head slow_virtqueues;
  78
  79         /* Array of all virtqueues reported in the
  80          * PCI common config num_queues field
  81          */
  82         struct virtio_pci_vq_info **vqs;
  83
  84         struct virtio_pci_admin_vq admin_vq;
  85
  86         /* MSI-X support */
  87         int msix_enabled;
  88         int intx_enabled;
  89         cpumask_var_t *msix_affinity_masks;
  90         /* Name strings for interrupts. This size should be enough,
  91          * and I'm too lazy to allocate each name separately. */
  92         char (*msix_names)[256];
  93         /* Number of available vectors */
  94         unsigned int msix_vectors;
  95         /* Vectors allocated, excluding per-vq vectors if any */
  96         unsigned int msix_used_vectors;
  97
  98         /* Whether we have vector per vq */
  99         bool per_vq_vectors;
 100
 101         struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
 102                                       struct virtio_pci_vq_info *info,
 103                                       unsigned int idx,
 104                                       void (*callback)(struct virtqueue *vq),
 105                                       const char *name,
 106                                       bool ctx,
 107                                       u16 msix_vec);
 108         void (*del_vq)(struct virtio_pci_vq_info *info);
 109
 110         u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 111         int (*avq_index)(struct virtio_device *vdev, u16 *index, u16 *num);
 112 };
 113
 114 /* Constants for MSI-X */
 115 /* Use first vector for configuration changes, second and the rest for
 116  * virtqueues Thus, we need at least 2 vectors for MSI. */
 117 enum {
 118         VP_MSIX_CONFIG_VECTOR = 0,
 119         VP_MSIX_VQ_VECTOR = 1,
 120 };
 121
 122 /* Convert a generic virtio device to our structure */
 123 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 124 {
 125         return container_of(vdev, struct virtio_pci_device, vdev);
 126 }
 127
 128 /* wait for pending irq handlers */
 129 void vp_synchronize_vectors(struct virtio_device *vdev);
 130 /* the notify function used when creating a virt queue */
 131 bool vp_notify(struct virtqueue *vq);
 132 /* the config->del_vqs() implementation */
 133 void vp_del_vqs(struct virtio_device *vdev);
 134 /* the config->find_vqs() implementation */
 135 int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
 136                 struct virtqueue *vqs[], struct virtqueue_info vqs_info[],
 137                 struct irq_affinity *desc);
 138 const char *vp_bus_name(struct virtio_device *vdev);
 139
 140 /* Setup the affinity for a virtqueue:
 141  * - force the affinity for per vq vector
 142  * - OR over all affinities for shared MSI
 143  * - ignore the affinity request if we're using INTX
 144  */
 145 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
 146
 147 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
 148
 149 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 150 int virtio_pci_legacy_probe(struct virtio_pci_device *);
 151 void virtio_pci_legacy_remove(struct virtio_pci_device *);
 152 #else
 153 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 154 {
 155         return -ENODEV;
 156 }
 157 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 158 {
 159 }
 160 #endif
 161 int virtio_pci_modern_probe(struct virtio_pci_device *);
 162 void virtio_pci_modern_remove(struct virtio_pci_device *);
 163
 164 struct virtio_device *virtio_pci_vf_get_pf_dev(struct pci_dev *pdev);
 165
 166 #define VIRTIO_LEGACY_ADMIN_CMD_BITMAP \
 167         (BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE) | \
 168          BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ) | \
 169          BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE) | \
 170          BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ) | \
 171          BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO))
 172
 173 #define VIRTIO_DEV_PARTS_ADMIN_CMD_BITMAP \
 174         (BIT_ULL(VIRTIO_ADMIN_CMD_CAP_ID_LIST_QUERY) | \
 175          BIT_ULL(VIRTIO_ADMIN_CMD_DRIVER_CAP_SET) | \
 176          BIT_ULL(VIRTIO_ADMIN_CMD_DEVICE_CAP_GET) | \
 177          BIT_ULL(VIRTIO_ADMIN_CMD_RESOURCE_OBJ_CREATE) | \
 178          BIT_ULL(VIRTIO_ADMIN_CMD_RESOURCE_OBJ_DESTROY) | \
 179          BIT_ULL(VIRTIO_ADMIN_CMD_DEV_PARTS_METADATA_GET) | \
 180          BIT_ULL(VIRTIO_ADMIN_CMD_DEV_PARTS_GET) | \
 181          BIT_ULL(VIRTIO_ADMIN_CMD_DEV_PARTS_SET) | \
 182          BIT_ULL(VIRTIO_ADMIN_CMD_DEV_MODE_SET))
 183
 184 /* Unlike modern drivers which support hardware virtio devices, legacy drivers
 185  * assume software-based devices: e.g. they don't use proper memory barriers
 186  * on ARM, use big endian on PPC, etc. X86 drivers are mostly ok though, more
 187  * or less by chance. For now, only support legacy IO on X86.
 188  */
 189 #ifdef CONFIG_VIRTIO_PCI_ADMIN_LEGACY
 190 #define VIRTIO_ADMIN_CMD_BITMAP (VIRTIO_LEGACY_ADMIN_CMD_BITMAP | \
 191                                  VIRTIO_DEV_PARTS_ADMIN_CMD_BITMAP)
 192 #else
 193 #define VIRTIO_ADMIN_CMD_BITMAP VIRTIO_DEV_PARTS_ADMIN_CMD_BITMAP
 194 #endif
 195
 196 bool vp_is_avq(struct virtio_device *vdev, unsigned int index);
 197 void vp_modern_avq_done(struct virtqueue *vq);
 198 int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
 199                              struct virtio_admin_cmd *cmd);
 200
 201 #endif