| Message ID | 20190621094005.4134-4-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | libvhost-user: VHOST_USER_PROTOCOL_F_MQ support | expand |
On Fri, Jun 21, 2019 at 11:40 AM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > Existing vhost-user device backends, including vhost-user-scsi and > vhost-user-blk, support multiqueue but libvhost-user currently does not > advertise this. > > VHOST_USER_PROTOCOL_F_MQ enables the VHOST_USER_GET_QUEUE_NUM request > needed for a vhost-user master to query the number of queues. For > example, QEMU's vhost-user-net master depends on > VHOST_USER_PROTOCOL_F_MQ for multiqueue. > > If you're wondering how any device backend with more than one virtqueue > functions today, it's because device types with a fixed number of > virtqueues do not require querying the number of queues. Therefore the > vhost-user master for vhost-user-input with 2 virtqueues, for example, > doesn't actually depend on VHOST_USER_PROTOCOL_F_MQ. It just enables > virtqueues 0 and 1 without asking. > > Let there be multiqueue! > > Suggested-by: Sebastien Boeuf <sebastien.boeuf@intel.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > --- > contrib/libvhost-user/libvhost-user.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c > index 0c88431e8f..312c54f260 100644 > --- a/contrib/libvhost-user/libvhost-user.c > +++ b/contrib/libvhost-user/libvhost-user.c > @@ -1160,7 +1160,8 @@ vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg) > static bool > vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) > { > - uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD | > + uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_MQ | > + 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD | > 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ | > 1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER | > 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD; > @@ -1200,8 +1201,8 @@ vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) > static bool > vu_get_queue_num_exec(VuDev *dev, VhostUserMsg *vmsg) > { > - DPRINT("Function %s() not implemented yet.\n", __func__); > - return false; > + vmsg_set_reply_u64(vmsg, dev->max_queues); > + return true; > } > > static bool > -- > 2.21.0 >
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index 0c88431e8f..312c54f260 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -1160,7 +1160,8 @@ vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg) static bool vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) { - uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD | + uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_MQ | + 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD | 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ | 1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER | 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD; @@ -1200,8 +1201,8 @@ vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) static bool vu_get_queue_num_exec(VuDev *dev, VhostUserMsg *vmsg) { - DPRINT("Function %s() not implemented yet.\n", __func__); - return false; + vmsg_set_reply_u64(vmsg, dev->max_queues); + return true; } static bool
Existing vhost-user device backends, including vhost-user-scsi and vhost-user-blk, support multiqueue but libvhost-user currently does not advertise this. VHOST_USER_PROTOCOL_F_MQ enables the VHOST_USER_GET_QUEUE_NUM request needed for a vhost-user master to query the number of queues. For example, QEMU's vhost-user-net master depends on VHOST_USER_PROTOCOL_F_MQ for multiqueue. If you're wondering how any device backend with more than one virtqueue functions today, it's because device types with a fixed number of virtqueues do not require querying the number of queues. Therefore the vhost-user master for vhost-user-input with 2 virtqueues, for example, doesn't actually depend on VHOST_USER_PROTOCOL_F_MQ. It just enables virtqueues 0 and 1 without asking. Let there be multiqueue! Suggested-by: Sebastien Boeuf <sebastien.boeuf@intel.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- contrib/libvhost-user/libvhost-user.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)