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