| Message ID | 1648621997-22416-4-git-send-email-si-wei.liu@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vhost-vdpa multiqueue fixes | expand |
On Wed, Mar 30, 2022 at 2:33 PM Si-Wei Liu <si-wei.liu@oracle.com> wrote: > > From: Eugenio Pérez <eperezma@redhat.com> > > Qemu falls back on userland handlers even if vhost-user and vhost-vdpa > cases. These assumes a tap device can handle the packets. > > If a vdpa device fail to start, it can trigger a sigsegv because of > that. Do not resort on them unless actually possible. What kind of segsev you've seen. If my memory is correct we finally choose to have a dummy receive() for vhost-vDPA in commit 846a1e85da646c6006db429648389fc110f92d75 Author: Eugenio Pérez <eperezma@redhat.com> Date: Thu Nov 25 11:16:13 2021 +0100 vdpa: Add dummy receive callback Qemu falls back on userland handlers even if vhost-user and vhost-vdpa cases. These assumes a tap device can handle the packets. If a vdpa device fail to start, it can trigger a sigsegv because of that. Add dummy receiver that returns no progress so it can keep running. Fixes: 1e0a84ea49 ("vhost-vdpa: introduce vhost-vdpa net client") Signed-off-by: Eugenio Pérez <eperezma@redhat.com> Message-Id: <20211125101614.76927-2-eperezma@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> (Technically, we can have a vhost-vDPA networking backend (not vhost backend)) > > Signed-off-by: Eugenio Pérez <eperezma@redhat.com> > --- > hw/net/virtio-net.c | 4 ++++ > hw/virtio/virtio.c | 21 +++++++++++++-------- > include/hw/virtio/virtio.h | 2 ++ > 3 files changed, 19 insertions(+), 8 deletions(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index ffaf481..9cdf777 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -3523,6 +3523,10 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) > nc = qemu_get_queue(n->nic); > nc->rxfilter_notify_enabled = 1; > > + if (!nc->peer || nc->peer->info->type != NET_CLIENT_DRIVER_TAP) { > + /* Only tap can use userspace networking */ > + vdev->disable_ioeventfd_handler = true; > + } > if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) { > struct virtio_net_config netcfg = {}; > memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN); > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 9d637e0..806603b 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -3708,17 +3708,22 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) > err = r; > goto assign_error; > } > - event_notifier_set_handler(&vq->host_notifier, > - virtio_queue_host_notifier_read); > + > + if (!vdev->disable_ioeventfd_handler) { > + event_notifier_set_handler(&vq->host_notifier, > + virtio_queue_host_notifier_read); > + } > } > > - for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { > - /* Kick right away to begin processing requests already in vring */ > - VirtQueue *vq = &vdev->vq[n]; > - if (!vq->vring.num) { > - continue; > + if (!vdev->disable_ioeventfd_handler) { > + for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { > + /* Kick right away to begin processing requests already in vring */ > + VirtQueue *vq = &vdev->vq[n]; > + if (!vq->vring.num) { > + continue; > + } > + event_notifier_set(&vq->host_notifier); > } > - event_notifier_set(&vq->host_notifier); > } > memory_region_transaction_commit(); > return 0; > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index b31c450..b6ce5f0 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -105,6 +105,8 @@ struct VirtIODevice > VMChangeStateEntry *vmstate; > char *bus_name; > uint8_t device_endian; > + /* backend does not support userspace handler */ > + bool disable_ioeventfd_handler; > bool use_guest_notifier_mask; > AddressSpace *dma_as; > QLIST_HEAD(, VirtQueue) *vector_queues; > -- > 1.8.3.1 >
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index ffaf481..9cdf777 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -3523,6 +3523,10 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) nc = qemu_get_queue(n->nic); nc->rxfilter_notify_enabled = 1; + if (!nc->peer || nc->peer->info->type != NET_CLIENT_DRIVER_TAP) { + /* Only tap can use userspace networking */ + vdev->disable_ioeventfd_handler = true; + } if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) { struct virtio_net_config netcfg = {}; memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN); diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 9d637e0..806603b 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -3708,17 +3708,22 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) err = r; goto assign_error; } - event_notifier_set_handler(&vq->host_notifier, - virtio_queue_host_notifier_read); + + if (!vdev->disable_ioeventfd_handler) { + event_notifier_set_handler(&vq->host_notifier, + virtio_queue_host_notifier_read); + } } - for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { - /* Kick right away to begin processing requests already in vring */ - VirtQueue *vq = &vdev->vq[n]; - if (!vq->vring.num) { - continue; + if (!vdev->disable_ioeventfd_handler) { + for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { + /* Kick right away to begin processing requests already in vring */ + VirtQueue *vq = &vdev->vq[n]; + if (!vq->vring.num) { + continue; + } + event_notifier_set(&vq->host_notifier); } - event_notifier_set(&vq->host_notifier); } memory_region_transaction_commit(); return 0; diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index b31c450..b6ce5f0 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -105,6 +105,8 @@ struct VirtIODevice VMChangeStateEntry *vmstate; char *bus_name; uint8_t device_endian; + /* backend does not support userspace handler */ + bool disable_ioeventfd_handler; bool use_guest_notifier_mask; AddressSpace *dma_as; QLIST_HEAD(, VirtQueue) *vector_queues;