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 */ 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 148 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) 149 { 150 return -ENODEV; 151 } 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