vhost-vdpa: allow passing opened vhostfd to vhost-vdpa

Similar to other vhost backends, vhostfd can be passed to vhost-vdpa
backend as another parameter to instantiate vhost-vdpa net client.
This would benefit the use case where only open file descriptors, as
opposed to raw vhost-vdpa device paths, are accessible from the QEMU
process.

(qemu) netdev_add type=vhost-vdpa,vhostfd=61,id=vhost-vdpa1

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Si-Wei Liu 2022-10-08 00:58:58 -07:00 committed by Jason Wang
parent 6ce262fbe7
commit 8801ccd050
3 changed files with 27 additions and 7 deletions

View File

@ -634,15 +634,30 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
opts = &netdev->u.vhost_vdpa;
if (!opts->vhostdev) {
error_setg(errp, "vdpa character device not specified with vhostdev");
if (!opts->has_vhostdev && !opts->has_vhostfd) {
error_setg(errp,
"vhost-vdpa: neither vhostdev= nor vhostfd= was specified");
return -1;
}
if (opts->has_vhostdev && opts->has_vhostfd) {
error_setg(errp,
"vhost-vdpa: vhostdev= and vhostfd= are mutually exclusive");
return -1;
}
if (opts->has_vhostdev) {
vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR, errp);
if (vdpa_device_fd == -1) {
return -errno;
}
} else if (opts->has_vhostfd) {
vdpa_device_fd = monitor_fd_param(monitor_cur(), opts->vhostfd, errp);
if (vdpa_device_fd == -1) {
error_prepend(errp, "vhost-vdpa: unable to parse vhostfd: ");
return -1;
}
}
r = vhost_vdpa_get_features(vdpa_device_fd, &features, errp);
if (unlikely(r < 0)) {

View File

@ -442,6 +442,8 @@
# @vhostdev: path of vhost-vdpa device
# (default:'/dev/vhost-vdpa-0')
#
# @vhostfd: file descriptor of an already opened vhost vdpa device
#
# @queues: number of queues to be created for multiqueue vhost-vdpa
# (default: 1)
#
@ -456,6 +458,7 @@
{ 'struct': 'NetdevVhostVDPAOptions',
'data': {
'*vhostdev': 'str',
'*vhostfd': 'str',
'*queues': 'int',
'*x-svq': {'type': 'bool', 'features' : [ 'unstable'] } } }

View File

@ -2790,8 +2790,10 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
" configure a vhost-user network, backed by a chardev 'dev'\n"
#endif
#ifdef __linux__
"-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n"
"-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n"
" configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
" use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n"
" use 'vhostfd=h' to connect to an already opened vhost vdpa device\n"
#endif
#ifdef CONFIG_VMNET
"-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n"
@ -3296,7 +3298,7 @@ SRST
-netdev type=vhost-user,id=net0,chardev=chr0 \
-device virtio-net-pci,netdev=net0
``-netdev vhost-vdpa,vhostdev=/path/to/dev``
``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]``
Establish a vhost-vdpa netdev.
vDPA device is a device that uses a datapath which complies with