qemu vhost_net + vhost_dev_init

https://blog.csdn.net/qq_20817327/article/details/106655151

net/tap.c 

static void net_init_tap_one
{
699             vhostfd = open("/dev/vhost-net", O_RDWR);
700             if (vhostfd < 0) {
701                 if (tap->has_vhostforce && tap->vhostforce) {
702                     error_setg_errno(errp, errno,
703                                      "tap: open vhost char device failed");
704                 } else {
705                     warn_report("tap: open vhost char device failed: %s",
706                                 strerror(errno));
707                 }
708                 return;
709             }
710             qemu_set_nonblock(vhostfd);
711         }
712         options.opaque = (void *)(uintptr_t)vhostfd;
713 
714         s->vhost_net = vhost_net_init(&options);
}

 vhost_virtqueue_init

[root@bogon qemu]# grep 'vhost_ops =' -rn *
backends/cryptodev-vhost.c:161:    vhost_ops = crypto->dev.vhost_ops;
hw/virtio/vhost-vsock.c:42:    const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
hw/virtio/vhost-vsock.c:59:    const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
hw/virtio/vhost-backend.c:280:        dev->vhost_ops = &kernel_ops;
hw/virtio/vhost-backend.c:285:        dev->vhost_ops = &user_ops;
hw/scsi/vhost-scsi.c:46:    const VhostOps *vhost_ops = vsc->dev.vhost_ops;
hw/scsi/vhost-scsi.c:64:    const VhostOps *vhost_ops = vsc->dev.vhost_ops;
hw/scsi/vhost-scsi.c:75:    const VhostOps *vhost_ops = vsc->dev.vhost_ops;
hw/net/vhost_net.c:384:    const VhostOps *vhost_ops = net->dev.vhost_ops;
hw/net/vhost_net.c:431:    const VhostOps *vhost_ops = net->dev.vhost_ops;
hw/net/vhost_net.c:444:    const VhostOps *vhost_ops = net->dev.vhost_ops;
[root@bogon qemu]# 

[root@bogon qemu]# grep 'vhost_net =' -rn *
hw/net/vhost_net.c:405:    VHostNetState *vhost_net = 0;
hw/net/vhost_net.c:413:        vhost_net = tap_get_vhost_net(nc);
hw/net/vhost_net.c:417:        vhost_net = vhost_user_get_vhost_net(nc);
net/vhost-user.c:107:        s->vhost_net = net;
net/vhost-user.c:157:        s->vhost_net = NULL;
net/tap.c:317:        s->vhost_net = NULL;
net/tap.c:392:    s->vhost_net = NULL;
net/tap.c:714:        s->vhost_net = vhost_net_init(&options)

403 VHostNetState *get_vhost_net(NetClientState *nc)
404 {
405     VHostNetState *vhost_net = 0;
406 
407     if (!nc) {
408         return 0;
409     }
410 
411     switch (nc->info->type) {
412     case NET_CLIENT_DRIVER_TAP:
413         vhost_net = tap_get_vhost_net(nc);
414         break;
415 #ifdef CONFIG_VHOST_NET_USER
416     case NET_CLIENT_DRIVER_VHOST_USER:
417         vhost_net = vhost_user_get_vhost_net(nc);
418         assert(vhost_net);
419         break;
420 #endif
421     default:
422         break;
423     }
424 
425     return vhost_net;
426 }

[root@bogon qemu]# grep vhost_user_get_vhost_net -rn *
Binary file build/aarch64-softmmu/qemu-system-aarch64 matches
Binary file build/net/vhost-user.o matches
Binary file build/hw/net/vhost_net.o matches
hw/net/vhost_net.c:417:        vhost_net = vhost_user_get_vhost_net(nc);
include/net/vhost-user.h:15:struct vhost_net *vhost_user_get_vhost_net(NetClientState *nc);
net/vhost-user.c:34:VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
[root@bogon qemu]# vi 

1147 static int vhost_virtqueue_init(struct vhost_dev *dev,
1148                                 struct vhost_virtqueue *vq, int n)
1149 {
1150     int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n);
1151     struct vhost_vring_file file = {
1152         .index = vhost_vq_index,
1153     };
1154     int r = event_notifier_init(&vq->masked_notifier, 0);
1155     if (r < 0) {
1156         return r;
1157     }
1158 
1159     file.fd = event_notifier_get_fd(&vq->masked_notifier);
1160     r = dev->vhost_ops->vhost_set_vring_call(dev, &file);
1161     if (r) {
1162         VHOST_OPS_DEBUG("vhost_set_vring_call failed");
1163         r = -errno;
1164         goto fail_call;
1165     }
1166 
1167     vq->dev = dev;
1168 
1169     return 0;
1170 fail_call:
1171     event_notifier_cleanup(&vq->masked_notifier);
1172     return r;
1173 }
hw/virtio/vhost.c 

hw/virtio/vhost.c:1043:        r = dev->vhost_ops->vhost_set_vring_call(dev, &file);
hw/virtio/vhost.c:1160:    r = dev->vhost_ops->vhost_set_vring_call(dev, &file);
hw/virtio/vhost.c:1162:        VHOST_OPS_DEBUG("vhost_set_vring_call failed");
hw/virtio/vhost.c:1420:    r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file);
hw/virtio/vhost.c:1422:        VHOST_OPS_DEBUG("vhost_set_vring_call failed");
hw/virtio/vhost-user.c:1935:        .vhost_set_vring_call = vhost_user_set_vring_call,
hw/virtio/vhost-backend.c:256:        .vhost_set_vring_call = vhost_kernel_set_vring_call,
include/hw/virtio/vhost-backend.h:67:typedef int (*vhost_set_vring_call_op)(struct vhost_dev *dev,
include/hw/virtio/vhost-backend.h:133:    vhost_set_vring_call_op vhost_set_vring_call;
[root@bogon qemu]# 

vhost_kernel_set_vring_call

139 static int vhost_kernel_set_vring_call(struct vhost_dev *dev,
140                                        struct vhost_vring_file *file)
141 {
142     return vhost_kernel_call(dev, VHOST_SET_VRING_CALL, file);
143 }

 21 static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
 22                              void *arg)
 23 {
 24     int fd = (uintptr_t) dev->opaque;
 25 
 26     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
 27 
 28     return ioctl(fd, request, arg);
 29 }

vhost_user_set_vring_call

 795 static int vhost_user_set_vring_call(struct vhost_dev *dev,
 796                                      struct vhost_vring_file *file)
 797 {
 798     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
 799 }

 763 static int vhost_set_vring_file(struct vhost_dev *dev,
 764                                 VhostUserRequest request,
 765                                 struct vhost_vring_file *file)
 766 {
 767     int fds[VHOST_MEMORY_MAX_NREGIONS];
 768     size_t fd_num = 0;
 769     VhostUserMsg msg = {
 770         .hdr.request = request,
 771         .hdr.flags = VHOST_USER_VERSION,
 772         .payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
 773         .hdr.size = sizeof(msg.payload.u64),
 774     };
 775 
 776     if (ioeventfd_enabled() && file->fd > 0) {
 777         fds[fd_num++] = file->fd;
 778     } else {
 779         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
 780     }
 781 
 782     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
 783         return -1;
 784     }
 785 
 786     return 0;
 787 }