bwlp/qemu.git/hw/virtio, branch spice_video_codecs

hw/virtio: generalise CHR_EVENT_CLOSED handling

2022-12-01T07:30:13+00:00

..and use for both virtio-user-blk and virtio-user-gpio. This avoids the circular close by deferring shutdown due to disconnection until a later point. virtio-user-blk already had this mechanism in place so generalise it as a vhost-user helper function and use for both blk and gpio devices. While we are at it we also fix up vhost-user-gpio to re-establish the event handler after close down so we can reconnect later. Signed-off-by: Alex Bennée Reviewed-by: Michael S. Tsirkin Reviewed-by: Raphael Norwitz Message-Id: <20221130112439.2527228-5-alex.bennee@linaro.org> Signed-off-by: Michael S. Tsirkin

hw/virtio: add started_vu status field to vhost-user-gpio

2022-12-01T07:30:09+00:00

As per the fix to vhost-user-blk in f5b22d06fb (vhost: recheck dev state in the vhost_migration_log routine) we really should track the connection and starting separately. Signed-off-by: Alex Bennée Reviewed-by: Michael S. Tsirkin Message-Id: <20221130112439.2527228-4-alex.bennee@linaro.org> Signed-off-by: Michael S. Tsirkin

vhost: enable vrings in vhost_dev_start() for vhost-user devices

2022-12-01T07:30:04+00:00

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 Tested-by: German Maglione Signed-off-by: Stefano Garzarella Acked-by: Raphael Norwitz Message-Id: <20221123131630.52020-1-sgarzare@redhat.com> Signed-off-by: Alex Bennée Reviewed-by: Michael S. Tsirkin Message-Id: <20221130112439.2527228-3-alex.bennee@linaro.org> Signed-off-by: Michael S. Tsirkin

virtio: disable error for out of spec queue-enable

2022-11-22T10:19:00+00:00

Virtio 1.0 is pretty clear that features have to be negotiated before enabling VQs. Unfortunately Seabios ignored this ever since gaining 1.0 support (UEFI is ok). Comment the error out for now, and add a TODO. Fixes: 3c37f8b8d1 ("virtio: introduce virtio_queue_enable()") Cc: "Kangjie Xu" Signed-off-by: Michael S. Tsirkin Message-Id: <20221121200339.362452-1-mst@redhat.com>

vhost: mask VIRTIO_F_RING_RESET for vhost and vhost-user devices

2022-11-22T10:19:00+00:00

Commit 69e1c14aa2 ("virtio: core: vq reset feature negotation support") enabled VIRTIO_F_RING_RESET by default for all virtio devices. This feature is not currently emulated by QEMU, so for vhost and vhost-user devices we need to make sure it is supported by the offloaded device emulation (in-kernel or in another process). To do this we need to add VIRTIO_F_RING_RESET to the features bitmap passed to vhost_get_features(). This way it will be masked if the device does not support it. This issue was initially discovered with vhost-vsock and vhost-user-vsock, and then also tested with vhost-user-rng which confirmed the same issue. They fail when sending features through VHOST_SET_FEATURES ioctl or VHOST_USER_SET_FEATURES message, since VIRTIO_F_RING_RESET is negotiated by the guest (Linux >= v6.0), but not supported by the device. Fixes: 69e1c14aa2 ("virtio: core: vq reset feature negotation support") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1318 Signed-off-by: Stefano Garzarella Message-Id: <20221121101101.29400-1-sgarzare@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Acked-by: Raphael Norwitz Acked-by: Jason Wang

hw/virtio: introduce virtio_device_should_start

2022-11-07T19:08:18+00:00

The previous fix to virtio_device_started revealed a problem in its use by both the core and the device code. The core code should be able to handle the device "starting" while the VM isn't running to handle the restoration of migration state. To solve this duel use introduce a new helper for use by the vhost-user backends who all use it to feed a should_start variable. We can also pick up a change vhost_user_blk_set_status while we are at it which follows the same pattern. Fixes: 9f6bcfd99f (hw/virtio: move vm_running check to virtio_device_started) Signed-off-by: Alex Bennée Cc: "Michael S. Tsirkin" Message-Id: <20221107121407.1010913-1-alex.bennee@linaro.org>

vhost-user: Support vhost_dev_start

2022-11-07T19:08:17+00:00

The motivation of adding vhost-user vhost_dev_start support is to improve backend configuration speed and reduce live migration VM downtime. Today VQ configuration is issued one by one. For virtio net with multi-queue support, backend needs to update RSS (Receive side scaling) on every rx queue enable. Updating RSS is time-consuming (typical time like 7ms). Implement already defined vhost status and message in the vhost specification [1]. (a) VHOST_USER_PROTOCOL_F_STATUS (b) VHOST_USER_SET_STATUS (c) VHOST_USER_GET_STATUS Send message VHOST_USER_SET_STATUS with VIRTIO_CONFIG_S_DRIVER_OK for device start and reset(0) for device stop. On reception of the DRIVER_OK message, backend can apply the needed setting only once (instead of incremental) and also utilize parallelism on enabling queues. This improves QEMU's live migration downtime with vhost user backend implementation by great margin, specially for the large number of VQs of 64 from 800 msec to 250 msec. [1] https://qemu-project.gitlab.io/qemu/interop/vhost-user.html Signed-off-by: Yajun Wu Acked-by: Parav Pandit Message-Id: <20221017064452.1226514-3-yajunw@nvidia.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin

msix: Assert that specified vector is in range

2022-11-07T19:08:17+00:00

There were several different ways to deal with the situation where the vector specified for a msix function is out of bound: - early return a function and keep progresssing - propagate the error to the caller - mark msix unusable - assert it is in bound - just ignore An out-of-bound vector should not be specified if the device implementation is correct so let msix functions always assert that the specified vector is in range. An exceptional case is virtio-pci, which allows the guest to configure vectors. For virtio-pci, it is more appropriate to introduce its own checks because it is sometimes too late to check the vector range in msix functions. Signed-off-by: Akihiko Odaki Message-Id: <20220829083524.143640-1-akihiko.odaki@daynix.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Yuval Shaia Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>

vhost-user: Fix out of order vring host notification handling

2022-11-07T18:12:20+00:00

vhost backend sends host notification for every VQ. If backend creates VQs in parallel, the VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG may arrive to QEMU in different order than incremental queue index order. For example VQ 1's message arrive earlier than VQ 0's: After alloc VhostUserHostNotifier for VQ 1. GPtrArray becomes [ nil, VQ1 pointer ] After alloc VhostUserHostNotifier for VQ 0. GPtrArray becomes [ VQ0 pointer, nil, VQ1 pointer ] This is wrong. fetch_notifier will return NULL for VQ 1 in vhost_user_get_vring_base, causes host notifier miss removal(leak). The fix is to remove current element from GPtrArray, make the right position for element to insert. Fixes: 503e355465 ("virtio/vhost-user: dynamically assign VhostUserHostNotifiers") Signed-off-by: Yajun Wu Acked-by: Parav Pandit Message-Id: <20221018023651.1359420-1-yajunw@nvidia.com> Reviewed-by: Alex Bennée Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin

virtio-rng-pci: Allow setting nvectors, so we can use MSI-X

2022-11-07T18:12:20+00:00

Most other virtio-pci devices allow MSI-X, let's have it for rng too. Signed-off-by: David Daney Reviewed-by: Marcin Nowakowski Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20221014160947.66105-1-philmd@fungible.com> Reviewed-by: Stefan Hajnoczi Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin