1 /* 2 * vhost-backend 3 * 4 * Copyright (c) 2013 Virtual Open Systems Sarl. 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 #include "hw/virtio/vhost.h" 13 #include "hw/virtio/vhost-backend.h" 14 #include "qemu/error-report.h" 15 #include "linux/vhost.h" 16 17 #include <sys/ioctl.h> 18 19 static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request, 20 void *arg) 21 { 22 int fd = (uintptr_t) dev->opaque; 23 24 assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL); 25 26 return ioctl(fd, request, arg); 27 } 28 29 static int vhost_kernel_init(struct vhost_dev *dev, void *opaque) 30 { 31 assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL); 32 33 dev->opaque = opaque; 34 35 return 0; 36 } 37 38 static int vhost_kernel_cleanup(struct vhost_dev *dev) 39 { 40 int fd = (uintptr_t) dev->opaque; 41 42 assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL); 43 44 return close(fd); 45 } 46 47 static int vhost_kernel_memslots_limit(struct vhost_dev *dev) 48 { 49 int limit = 64; 50 char *s; 51 52 if (g_file_get_contents("/sys/module/vhost/parameters/max_mem_regions", 53 &s, NULL, NULL)) { 54 uint64_t val = g_ascii_strtoull(s, NULL, 10); 55 if (!((val == G_MAXUINT64 || !val) && errno)) { 56 return val; 57 } 58 error_report("ignoring invalid max_mem_regions value in vhost module:" 59 " %s", s); 60 } 61 return limit; 62 } 63 64 static int vhost_kernel_net_set_backend(struct vhost_dev *dev, 65 struct vhost_vring_file *file) 66 { 67 return vhost_kernel_call(dev, VHOST_NET_SET_BACKEND, file); 68 } 69 70 static int vhost_kernel_scsi_set_endpoint(struct vhost_dev *dev, 71 struct vhost_scsi_target *target) 72 { 73 return vhost_kernel_call(dev, VHOST_SCSI_SET_ENDPOINT, target); 74 } 75 76 static int vhost_kernel_scsi_clear_endpoint(struct vhost_dev *dev, 77 struct vhost_scsi_target *target) 78 { 79 return vhost_kernel_call(dev, VHOST_SCSI_CLEAR_ENDPOINT, target); 80 } 81 82 static int vhost_kernel_scsi_get_abi_version(struct vhost_dev *dev, int *version) 83 { 84 return vhost_kernel_call(dev, VHOST_SCSI_GET_ABI_VERSION, version); 85 } 86 87 static int vhost_kernel_set_log_base(struct vhost_dev *dev, uint64_t base, 88 struct vhost_log *log) 89 { 90 return vhost_kernel_call(dev, VHOST_SET_LOG_BASE, &base); 91 } 92 93 static int vhost_kernel_set_mem_table(struct vhost_dev *dev, 94 struct vhost_memory *mem) 95 { 96 return vhost_kernel_call(dev, VHOST_SET_MEM_TABLE, mem); 97 } 98 99 static int vhost_kernel_set_vring_addr(struct vhost_dev *dev, 100 struct vhost_vring_addr *addr) 101 { 102 return vhost_kernel_call(dev, VHOST_SET_VRING_ADDR, addr); 103 } 104 105 static int vhost_kernel_set_vring_endian(struct vhost_dev *dev, 106 struct vhost_vring_state *ring) 107 { 108 return vhost_kernel_call(dev, VHOST_SET_VRING_ENDIAN, ring); 109 } 110 111 static int vhost_kernel_set_vring_num(struct vhost_dev *dev, 112 struct vhost_vring_state *ring) 113 { 114 return vhost_kernel_call(dev, VHOST_SET_VRING_NUM, ring); 115 } 116 117 static int vhost_kernel_set_vring_base(struct vhost_dev *dev, 118 struct vhost_vring_state *ring) 119 { 120 return vhost_kernel_call(dev, VHOST_SET_VRING_BASE, ring); 121 } 122 123 static int vhost_kernel_get_vring_base(struct vhost_dev *dev, 124 struct vhost_vring_state *ring) 125 { 126 return vhost_kernel_call(dev, VHOST_GET_VRING_BASE, ring); 127 } 128 129 static int vhost_kernel_set_vring_kick(struct vhost_dev *dev, 130 struct vhost_vring_file *file) 131 { 132 return vhost_kernel_call(dev, VHOST_SET_VRING_KICK, file); 133 } 134 135 static int vhost_kernel_set_vring_call(struct vhost_dev *dev, 136 struct vhost_vring_file *file) 137 { 138 return vhost_kernel_call(dev, VHOST_SET_VRING_CALL, file); 139 } 140 141 static int vhost_kernel_set_features(struct vhost_dev *dev, 142 uint64_t features) 143 { 144 return vhost_kernel_call(dev, VHOST_SET_FEATURES, &features); 145 } 146 147 static int vhost_kernel_get_features(struct vhost_dev *dev, 148 uint64_t *features) 149 { 150 return vhost_kernel_call(dev, VHOST_GET_FEATURES, features); 151 } 152 153 static int vhost_kernel_set_owner(struct vhost_dev *dev) 154 { 155 return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL); 156 } 157 158 static int vhost_kernel_reset_device(struct vhost_dev *dev) 159 { 160 return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL); 161 } 162 163 static int vhost_kernel_get_vq_index(struct vhost_dev *dev, int idx) 164 { 165 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 166 167 return idx - dev->vq_index; 168 } 169 170 static const VhostOps kernel_ops = { 171 .backend_type = VHOST_BACKEND_TYPE_KERNEL, 172 .vhost_backend_init = vhost_kernel_init, 173 .vhost_backend_cleanup = vhost_kernel_cleanup, 174 .vhost_backend_memslots_limit = vhost_kernel_memslots_limit, 175 .vhost_net_set_backend = vhost_kernel_net_set_backend, 176 .vhost_scsi_set_endpoint = vhost_kernel_scsi_set_endpoint, 177 .vhost_scsi_clear_endpoint = vhost_kernel_scsi_clear_endpoint, 178 .vhost_scsi_get_abi_version = vhost_kernel_scsi_get_abi_version, 179 .vhost_set_log_base = vhost_kernel_set_log_base, 180 .vhost_set_mem_table = vhost_kernel_set_mem_table, 181 .vhost_set_vring_addr = vhost_kernel_set_vring_addr, 182 .vhost_set_vring_endian = vhost_kernel_set_vring_endian, 183 .vhost_set_vring_num = vhost_kernel_set_vring_num, 184 .vhost_set_vring_base = vhost_kernel_set_vring_base, 185 .vhost_get_vring_base = vhost_kernel_get_vring_base, 186 .vhost_set_vring_kick = vhost_kernel_set_vring_kick, 187 .vhost_set_vring_call = vhost_kernel_set_vring_call, 188 .vhost_set_features = vhost_kernel_set_features, 189 .vhost_get_features = vhost_kernel_get_features, 190 .vhost_set_owner = vhost_kernel_set_owner, 191 .vhost_reset_device = vhost_kernel_reset_device, 192 .vhost_get_vq_index = vhost_kernel_get_vq_index, 193 }; 194 195 int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type) 196 { 197 int r = 0; 198 199 switch (backend_type) { 200 case VHOST_BACKEND_TYPE_KERNEL: 201 dev->vhost_ops = &kernel_ops; 202 break; 203 case VHOST_BACKEND_TYPE_USER: 204 dev->vhost_ops = &user_ops; 205 break; 206 default: 207 error_report("Unknown vhost backend type"); 208 r = -1; 209 } 210 211 return r; 212 } 213