diff options
| author | Stefano Garzarella <sgarzare@redhat.com> | 2022-11-30 11:24:36 +0000 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-12-01 02:30:04 -0500 |
| commit | 4daa5054c599c8aec70f1264a01341a15921c145 (patch) | |
| tree | 82e6b78fedf0a4cdb056e0727fb64e1d1cbcdcb4 /backends | |
| parent | 523e40022fc9522bb6bc13e4ce9eb4d1613ab5dc (diff) | |
vhost: enable vrings in vhost_dev_start() for vhost-user devices
Commit 02b61f38d3 ("hw/virtio: incorporate backend features in features")
properly negotiates VHOST_USER_F_PROTOCOL_FEATURES with the vhost-user
backend, but we forgot to enable vrings as specified in
docs/interop/vhost-user.rst:
If ``VHOST_USER_F_PROTOCOL_FEATURES`` has not been negotiated, the
ring starts directly in the enabled state.
If ``VHOST_USER_F_PROTOCOL_FEATURES`` has been negotiated, the ring is
initialized in a disabled state and is enabled by
``VHOST_USER_SET_VRING_ENABLE`` with parameter 1.
Some vhost-user front-ends already did this by calling
vhost_ops.vhost_set_vring_enable() directly:
- backends/cryptodev-vhost.c
- hw/net/virtio-net.c
- hw/virtio/vhost-user-gpio.c
But most didn't do that, so we would leave the vrings disabled and some
backends would not work. We observed this issue with the rust version of
virtiofsd [1], which uses the event loop [2] provided by the
vhost-user-backend crate where requests are not processed if vring is
not enabled.
Let's fix this issue by enabling the vrings in vhost_dev_start() for
vhost-user front-ends that don't already do this directly. Same thing
also in vhost_dev_stop() where we disable vrings.
[1] https://gitlab.com/virtio-fs/virtiofsd
[2] https://github.com/rust-vmm/vhost/blob/240fc2966/crates/vhost-user-backend/src/event_loop.rs#L217
Fixes: 02b61f38d3 ("hw/virtio: incorporate backend features in features")
Reported-by: German Maglione <gmaglione@redhat.com>
Tested-by: German Maglione <gmaglione@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20221123131630.52020-1-sgarzare@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20221130112439.2527228-3-alex.bennee@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'backends')
| -rw-r--r-- | backends/cryptodev-vhost.c | 4 | ||||
| -rw-r--r-- | backends/vhost-user.c | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c index bc13e466b4..572f87b3be 100644 --- a/backends/cryptodev-vhost.c +++ b/backends/cryptodev-vhost.c @@ -94,7 +94,7 @@ cryptodev_vhost_start_one(CryptoDevBackendVhost *crypto, goto fail_notifiers; } - r = vhost_dev_start(&crypto->dev, dev); + r = vhost_dev_start(&crypto->dev, dev, false); if (r < 0) { goto fail_start; } @@ -111,7 +111,7 @@ static void cryptodev_vhost_stop_one(CryptoDevBackendVhost *crypto, VirtIODevice *dev) { - vhost_dev_stop(&crypto->dev, dev); + vhost_dev_stop(&crypto->dev, dev, false); vhost_dev_disable_notifiers(&crypto->dev, dev); } diff --git a/backends/vhost-user.c b/backends/vhost-user.c index 5dedb2d987..7bfcaef976 100644 --- a/backends/vhost-user.c +++ b/backends/vhost-user.c @@ -85,7 +85,7 @@ vhost_user_backend_start(VhostUserBackend *b) } b->dev.acked_features = b->vdev->guest_features; - ret = vhost_dev_start(&b->dev, b->vdev); + ret = vhost_dev_start(&b->dev, b->vdev, true); if (ret < 0) { error_report("Error start vhost dev"); goto err_guest_notifiers; @@ -120,7 +120,7 @@ vhost_user_backend_stop(VhostUserBackend *b) return; } - vhost_dev_stop(&b->dev, b->vdev); + vhost_dev_stop(&b->dev, b->vdev, true); if (k->set_guest_notifiers) { ret = k->set_guest_notifiers(qbus->parent, |