| Message ID | 20200831082737.10983-10-jasowang@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | refine vhost-vdpa initialization | expand |
On Mon, 31 Aug 2020 at 16:30, Jason Wang <jasowang@redhat.com> wrote: > > This patch allows to initialize vhost-vdpa network backend with pre > opened vhost-vdpa file descriptor. This is useful for running > unprivileged qemu through libvirt. > > Cc: Eric Blake <eblake@redhat.com> > Cc: Markus Armbruster <armbru@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > net/vhost-vdpa.c | 24 +++++++++++++++++++----- > qapi/net.json | 5 ++++- > 2 files changed, 23 insertions(+), 6 deletions(-) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 9a6f0b63d3..f6385cd264 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -206,20 +206,34 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name, > (char *)name, errp)) { > return -1; > } > - if (!opts->has_vhostdev) { > - error_setg(errp, "vhost-vdpa requires vhostdev to be set"); > + if (!(opts->has_vhostdev ^ opts->has_fd)) { > + error_setg(errp, "Vhost-vdpa requires either vhostdev or fd to be set"); > return -1; > } > > assert(name); > > nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, TYPE_VHOST_VDPA, name); > - snprintf(nc->info_str, sizeof(nc->info_str), "vhostdev=%s", opts->vhostdev); > + if (opts->has_vhostdev) { > + snprintf(nc->info_str, sizeof(nc->info_str), > + "vhostdev=%s", opts->vhostdev); > + vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR); > + if (vdpa_device_fd == -1) { > + error_setg(errp, "Fail to open vhost-vdpa device %s", > + opts->vhostdev); > + return -errno; > + } > + } else { > + snprintf(nc->info_str, sizeof(nc->info_str), "fd=%s", opts->fd); > + vdpa_device_fd = monitor_fd_param(cur_mon, opts->fd, errp); > + if (vdpa_device_fd == -1) { > + return -1; > + } > + } > > s = DO_UPCAST(VhostVDPAState, nc, nc); > - vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR); > if (vdpa_device_fd == -1) { > - error_setg(errp, "Fail to open vhost-vdpa device %s", opts->vhostdev); > + > return -errno; > } > s->vhost_vdpa.device_fd = vdpa_device_fd; > diff --git a/qapi/net.json b/qapi/net.json > index a2a94fad3e..5ad60c3045 100644 > --- a/qapi/net.json > +++ b/qapi/net.json > @@ -442,12 +442,15 @@ > # @queues: number of queues to be created for multiqueue vhost-vdpa > # (default: 1) > # > +# @fd: file descriptor of an already opened vhost-vdpa (since 5.2) > +# > # Since: 5.1 > ## > { 'struct': 'NetdevVhostVDPAOptions', > 'data': { > '*vhostdev': 'str', > - '*queues': 'int' } } > + '*queues': 'int', > + '*fd': 'str' } } > > ## > # @NetClientDriver: > -- > 2.20.1 > I think the latest code supported this part. you can pass a pre open file descriptor to it via the add-fd QMP command to /dev/fdset/NNN, and then pass the string "/dev/fdset/NNN" as vhostdev. so we don't need a special fd parameter here. Thanks Cindy
On 2020/8/31 下午7:16, Cindy Lu wrote: > On Mon, 31 Aug 2020 at 16:30, Jason Wang <jasowang@redhat.com> wrote: >> This patch allows to initialize vhost-vdpa network backend with pre >> opened vhost-vdpa file descriptor. This is useful for running >> unprivileged qemu through libvirt. >> >> Cc: Eric Blake <eblake@redhat.com> >> Cc: Markus Armbruster <armbru@redhat.com> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> net/vhost-vdpa.c | 24 +++++++++++++++++++----- >> qapi/net.json | 5 ++++- >> 2 files changed, 23 insertions(+), 6 deletions(-) >> >> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c >> index 9a6f0b63d3..f6385cd264 100644 >> --- a/net/vhost-vdpa.c >> +++ b/net/vhost-vdpa.c >> @@ -206,20 +206,34 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name, >> (char *)name, errp)) { >> return -1; >> } >> - if (!opts->has_vhostdev) { >> - error_setg(errp, "vhost-vdpa requires vhostdev to be set"); >> + if (!(opts->has_vhostdev ^ opts->has_fd)) { >> + error_setg(errp, "Vhost-vdpa requires either vhostdev or fd to be set"); >> return -1; >> } >> >> assert(name); >> >> nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, TYPE_VHOST_VDPA, name); >> - snprintf(nc->info_str, sizeof(nc->info_str), "vhostdev=%s", opts->vhostdev); >> + if (opts->has_vhostdev) { >> + snprintf(nc->info_str, sizeof(nc->info_str), >> + "vhostdev=%s", opts->vhostdev); >> + vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR); >> + if (vdpa_device_fd == -1) { >> + error_setg(errp, "Fail to open vhost-vdpa device %s", >> + opts->vhostdev); >> + return -errno; >> + } >> + } else { >> + snprintf(nc->info_str, sizeof(nc->info_str), "fd=%s", opts->fd); >> + vdpa_device_fd = monitor_fd_param(cur_mon, opts->fd, errp); >> + if (vdpa_device_fd == -1) { >> + return -1; >> + } >> + } >> >> s = DO_UPCAST(VhostVDPAState, nc, nc); >> - vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR); >> if (vdpa_device_fd == -1) { >> - error_setg(errp, "Fail to open vhost-vdpa device %s", opts->vhostdev); >> + >> return -errno; >> } >> s->vhost_vdpa.device_fd = vdpa_device_fd; >> diff --git a/qapi/net.json b/qapi/net.json >> index a2a94fad3e..5ad60c3045 100644 >> --- a/qapi/net.json >> +++ b/qapi/net.json >> @@ -442,12 +442,15 @@ >> # @queues: number of queues to be created for multiqueue vhost-vdpa >> # (default: 1) >> # >> +# @fd: file descriptor of an already opened vhost-vdpa (since 5.2) >> +# >> # Since: 5.1 >> ## >> { 'struct': 'NetdevVhostVDPAOptions', >> 'data': { >> '*vhostdev': 'str', >> - '*queues': 'int' } } >> + '*queues': 'int', >> + '*fd': 'str' } } >> >> ## >> # @NetClientDriver: >> -- >> 2.20.1 >> > I think the latest code supported this part. > you can pass a pre open file descriptor to it via the add-fd QMP > command to /dev/fdset/NNN, and then pass the string > "/dev/fdset/NNN" as vhostdev. so we don't need a special fd parameter here. Right, I forgot the fdset tricks. Thanks > Thanks > Cindy > >
On 8/31/20 6:16 AM, Cindy Lu wrote: > On Mon, 31 Aug 2020 at 16:30, Jason Wang <jasowang@redhat.com> wrote: >> >> This patch allows to initialize vhost-vdpa network backend with pre >> opened vhost-vdpa file descriptor. This is useful for running >> unprivileged qemu through libvirt. >> >> Cc: Eric Blake <eblake@redhat.com> >> Cc: Markus Armbruster <armbru@redhat.com> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> +++ b/qapi/net.json >> @@ -442,12 +442,15 @@ >> # @queues: number of queues to be created for multiqueue vhost-vdpa >> # (default: 1) >> # >> +# @fd: file descriptor of an already opened vhost-vdpa (since 5.2) >> +# >> # Since: 5.1 >> ## >> { 'struct': 'NetdevVhostVDPAOptions', >> 'data': { >> '*vhostdev': 'str', >> - '*queues': 'int' } } >> + '*queues': 'int', >> + '*fd': 'str' } } >> >> ## >> # @NetClientDriver: >> -- >> 2.20.1 >> > I think the latest code supported this part. > you can pass a pre open file descriptor to it via the add-fd QMP > command to /dev/fdset/NNN, and then pass the string > "/dev/fdset/NNN" as vhostdev. so we don't need a special fd parameter here. Correct - the 'vhostdev' parameter + magic filename is all the more that is needed to access a pre-opened fd, so no 'fd' parameter should be added.
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index 9a6f0b63d3..f6385cd264 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -206,20 +206,34 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name, (char *)name, errp)) { return -1; } - if (!opts->has_vhostdev) { - error_setg(errp, "vhost-vdpa requires vhostdev to be set"); + if (!(opts->has_vhostdev ^ opts->has_fd)) { + error_setg(errp, "Vhost-vdpa requires either vhostdev or fd to be set"); return -1; } assert(name); nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, TYPE_VHOST_VDPA, name); - snprintf(nc->info_str, sizeof(nc->info_str), "vhostdev=%s", opts->vhostdev); + if (opts->has_vhostdev) { + snprintf(nc->info_str, sizeof(nc->info_str), + "vhostdev=%s", opts->vhostdev); + vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR); + if (vdpa_device_fd == -1) { + error_setg(errp, "Fail to open vhost-vdpa device %s", + opts->vhostdev); + return -errno; + } + } else { + snprintf(nc->info_str, sizeof(nc->info_str), "fd=%s", opts->fd); + vdpa_device_fd = monitor_fd_param(cur_mon, opts->fd, errp); + if (vdpa_device_fd == -1) { + return -1; + } + } s = DO_UPCAST(VhostVDPAState, nc, nc); - vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR); if (vdpa_device_fd == -1) { - error_setg(errp, "Fail to open vhost-vdpa device %s", opts->vhostdev); + return -errno; } s->vhost_vdpa.device_fd = vdpa_device_fd; diff --git a/qapi/net.json b/qapi/net.json index a2a94fad3e..5ad60c3045 100644 --- a/qapi/net.json +++ b/qapi/net.json @@ -442,12 +442,15 @@ # @queues: number of queues to be created for multiqueue vhost-vdpa # (default: 1) # +# @fd: file descriptor of an already opened vhost-vdpa (since 5.2) +# # Since: 5.1 ## { 'struct': 'NetdevVhostVDPAOptions', 'data': { '*vhostdev': 'str', - '*queues': 'int' } } + '*queues': 'int', + '*fd': 'str' } } ## # @NetClientDriver:
This patch allows to initialize vhost-vdpa network backend with pre opened vhost-vdpa file descriptor. This is useful for running unprivileged qemu through libvirt. Cc: Eric Blake <eblake@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- net/vhost-vdpa.c | 24 +++++++++++++++++++----- qapi/net.json | 5 ++++- 2 files changed, 23 insertions(+), 6 deletions(-)