From f0586baaa57c4042135b6d8f4d940da8a99e3737 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Wed, 30 Nov 2022 11:24:36 +0000 Subject: [PATCH] vhost: enable vrings in vhost_dev_start() for vhost-user devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: fangyi --- backends/cryptodev-vhost.c | 4 ++-- backends/vhost-user.c | 4 ++-- hw/block/vhost-user-blk.c | 4 ++-- hw/net/vhost_net.c | 6 ++--- hw/scsi/vhost-scsi-common.c | 4 ++-- hw/virtio/trace-events | 4 ++-- hw/virtio/vdpa-dev.c | 4 ++-- hw/virtio/vhost-user-fs.c | 4 ++-- hw/virtio/vhost-user-i2c.c | 4 ++-- hw/virtio/vhost-user-rng.c | 4 ++-- hw/virtio/vhost-vsock-common.c | 4 ++-- hw/virtio/vhost.c | 44 ++++++++++++++++++++++++++++++---- include/hw/virtio/vhost.h | 9 +++++-- 13 files changed, 69 insertions(+), 30 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 10b39992d2..6632e2fe6f 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, diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 9bf18434c2..eddc5588fa 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -167,7 +167,7 @@ static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp) goto err_guest_notifiers; } - ret = vhost_dev_start(&s->dev, vdev); + ret = vhost_dev_start(&s->dev, vdev, true); if (ret < 0) { error_setg_errno(errp, -ret, "Error starting vhost"); goto err_guest_notifiers; @@ -207,7 +207,7 @@ static void vhost_user_blk_stop(VirtIODevice *vdev) return; } - vhost_dev_stop(&s->dev, vdev); + vhost_dev_stop(&s->dev, vdev, true); ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); if (ret < 0) { diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index f709c060b6..c950d7e2e8 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -319,7 +319,7 @@ static int vhost_net_start_one(struct vhost_net *net, goto fail_notifiers; } - r = vhost_dev_start(&net->dev, dev); + r = vhost_dev_start(&net->dev, dev, false); if (r < 0) { goto fail_start; } @@ -368,7 +368,7 @@ fail: if (net->nc->info->poll) { net->nc->info->poll(net->nc, true); } - vhost_dev_stop(&net->dev, dev); + vhost_dev_stop(&net->dev, dev, false); fail_start: vhost_dev_disable_notifiers(&net->dev, dev); fail_notifiers: @@ -389,7 +389,7 @@ static void vhost_net_stop_one(struct vhost_net *net, if (net->nc->info->poll) { net->nc->info->poll(net->nc, true); } - vhost_dev_stop(&net->dev, dev); + vhost_dev_stop(&net->dev, dev, false); if (net->nc->info->stop) { net->nc->info->stop(net->nc); } diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c index 767f827e55..18ea5dcfa1 100644 --- a/hw/scsi/vhost-scsi-common.c +++ b/hw/scsi/vhost-scsi-common.c @@ -68,7 +68,7 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc) goto err_guest_notifiers; } - ret = vhost_dev_start(&vsc->dev, vdev); + ret = vhost_dev_start(&vsc->dev, vdev, true); if (ret < 0) { error_report("Error start vhost dev"); goto err_guest_notifiers; @@ -101,7 +101,7 @@ void vhost_scsi_common_stop(VHostSCSICommon *vsc) VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); int ret = 0; - vhost_dev_stop(&vsc->dev, vdev); + vhost_dev_stop(&vsc->dev, vdev, true); if (k->set_guest_notifiers) { ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false); diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events index b8a33b2a83..35d4c00e59 100644 --- a/hw/virtio/trace-events +++ b/hw/virtio/trace-events @@ -9,8 +9,8 @@ vhost_section(const char *name) "%s" vhost_reject_section(const char *name, int d) "%s:%d" vhost_iotlb_miss(void *dev, int step) "%p step %d" vhost_dev_cleanup(void *dev) "%p" -vhost_dev_start(void *dev, const char *name) "%p:%s" -vhost_dev_stop(void *dev, const char *name) "%p:%s" +vhost_dev_start(void *dev, const char *name, bool vrings) "%p:%s vrings:%d" +vhost_dev_stop(void *dev, const char *name, bool vrings) "%p:%s vrings:%d" # vhost-user.c diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c index 1840f0e450..465b08c0e3 100644 --- a/hw/virtio/vdpa-dev.c +++ b/hw/virtio/vdpa-dev.c @@ -242,7 +242,7 @@ static int vhost_vdpa_device_start(VirtIODevice *vdev, Error **errp) s->dev.acked_features = vdev->guest_features; - ret = vhost_dev_start(&s->dev, vdev); + ret = vhost_dev_start(&s->dev, vdev, false); if (ret < 0) { error_setg_errno(errp, -ret, "Error starting vhost"); goto err_guest_notifiers; @@ -283,7 +283,7 @@ static void vhost_vdpa_device_stop(VirtIODevice *vdev) return; } - vhost_dev_stop(&s->dev, vdev); + vhost_dev_stop(&s->dev, vdev, false); ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); if (ret < 0) { diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c index 392b7d3aa1..c2739557f2 100644 --- a/hw/virtio/vhost-user-fs.c +++ b/hw/virtio/vhost-user-fs.c @@ -74,7 +74,7 @@ static void vuf_start(VirtIODevice *vdev) } fs->vhost_dev.acked_features = vdev->guest_features; - ret = vhost_dev_start(&fs->vhost_dev, vdev); + ret = vhost_dev_start(&fs->vhost_dev, vdev, true); if (ret < 0) { error_report("Error starting vhost: %d", -ret); goto err_guest_notifiers; @@ -108,7 +108,7 @@ static void vuf_stop(VirtIODevice *vdev) return; } - vhost_dev_stop(&fs->vhost_dev, vdev); + vhost_dev_stop(&fs->vhost_dev, vdev, true); ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); if (ret < 0) { diff --git a/hw/virtio/vhost-user-i2c.c b/hw/virtio/vhost-user-i2c.c index d172632bb0..dcaf471115 100644 --- a/hw/virtio/vhost-user-i2c.c +++ b/hw/virtio/vhost-user-i2c.c @@ -45,7 +45,7 @@ static void vu_i2c_start(VirtIODevice *vdev) i2c->vhost_dev.acked_features = vdev->guest_features; - ret = vhost_dev_start(&i2c->vhost_dev, vdev); + ret = vhost_dev_start(&i2c->vhost_dev, vdev, true); if (ret < 0) { error_report("Error starting vhost-user-i2c: %d", -ret); goto err_guest_notifiers; @@ -79,7 +79,7 @@ static void vu_i2c_stop(VirtIODevice *vdev) return; } - vhost_dev_stop(&i2c->vhost_dev, vdev); + vhost_dev_stop(&i2c->vhost_dev, vdev, true); ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false); if (ret < 0) { diff --git a/hw/virtio/vhost-user-rng.c b/hw/virtio/vhost-user-rng.c index 543f3e3cef..f25b7cf624 100644 --- a/hw/virtio/vhost-user-rng.c +++ b/hw/virtio/vhost-user-rng.c @@ -42,7 +42,7 @@ static void vu_rng_start(VirtIODevice *vdev) } rng->vhost_dev.acked_features = vdev->guest_features; - ret = vhost_dev_start(&rng->vhost_dev, vdev); + ret = vhost_dev_start(&rng->vhost_dev, vdev, true); if (ret < 0) { error_report("Error starting vhost-user-rng: %d", -ret); goto err_guest_notifiers; @@ -76,7 +76,7 @@ static void vu_rng_stop(VirtIODevice *vdev) return; } - vhost_dev_stop(&rng->vhost_dev, vdev); + vhost_dev_stop(&rng->vhost_dev, vdev, true); ret = k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, false); if (ret < 0) { diff --git a/hw/virtio/vhost-vsock-common.c b/hw/virtio/vhost-vsock-common.c index cd45aaf28e..42e4db4712 100644 --- a/hw/virtio/vhost-vsock-common.c +++ b/hw/virtio/vhost-vsock-common.c @@ -68,7 +68,7 @@ int vhost_vsock_common_start(VirtIODevice *vdev) } vvc->vhost_dev.acked_features = vdev->guest_features; - ret = vhost_dev_start(&vvc->vhost_dev, vdev); + ret = vhost_dev_start(&vvc->vhost_dev, vdev, true); if (ret < 0) { error_report("Error starting vhost: %d", -ret); goto err_guest_notifiers; @@ -103,7 +103,7 @@ void vhost_vsock_common_stop(VirtIODevice *vdev) return; } - vhost_dev_stop(&vvc->vhost_dev, vdev); + vhost_dev_stop(&vvc->vhost_dev, vdev, true); ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false); if (ret < 0) { diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 86c727d2ab..22ec9e1ef7 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -1760,15 +1760,36 @@ int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, return 0; } +static int vhost_dev_set_vring_enable(struct vhost_dev *hdev, int enable) +{ + if (!hdev->vhost_ops->vhost_set_vring_enable) { + return 0; + } + + /* + * For vhost-user devices, if VHOST_USER_F_PROTOCOL_FEATURES has not + * been negotiated, the rings start directly in the enabled state, and + * .vhost_set_vring_enable callback will fail since + * VHOST_USER_SET_VRING_ENABLE is not supported. + */ + if (hdev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER && + !virtio_has_feature(hdev->backend_features, + VHOST_USER_F_PROTOCOL_FEATURES)) { + return 0; + } + + return hdev->vhost_ops->vhost_set_vring_enable(hdev, enable); +} + /* Host notifiers must be enabled at this point. */ -int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) +int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) { int i, r; /* should only be called after backend is connected */ assert(hdev->vhost_ops); - trace_vhost_dev_start(hdev, vdev->name); + trace_vhost_dev_start(hdev, vdev->name, vrings); vdev->vhost_started = true; hdev->started = true; @@ -1813,10 +1834,16 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) goto fail_log; } } + if (vrings) { + r = vhost_dev_set_vring_enable(hdev, true); + if (r) { + goto fail_log; + } + } if (hdev->vhost_ops->vhost_dev_start) { r = hdev->vhost_ops->vhost_dev_start(hdev, true); if (r) { - goto fail_log; + goto fail_start; } } if (vhost_dev_has_iommu(hdev) && @@ -1831,6 +1858,10 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) } } return 0; +fail_start: + if (vrings) { + vhost_dev_set_vring_enable(hdev, false); + } fail_log: vhost_log_put(hdev, false); fail_vq: @@ -1849,18 +1880,21 @@ fail_features: } /* Host notifiers must be enabled at this point. */ -void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) +void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) { int i; /* should only be called after backend is connected */ assert(hdev->vhost_ops); - trace_vhost_dev_stop(hdev, vdev->name); + trace_vhost_dev_stop(hdev, vdev->name, vrings); if (hdev->vhost_ops->vhost_dev_start) { hdev->vhost_ops->vhost_dev_start(hdev, false); } + if (vrings) { + vhost_dev_set_vring_enable(hdev, false); + } for (i = 0; i < hdev->nvqs; ++i) { vhost_virtqueue_stop(hdev, vdev, diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index d7ab2579ff..662e0f4370 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -5,6 +5,9 @@ #include "hw/virtio/virtio.h" #include "exec/memory.h" +#define VHOST_F_DEVICE_IOTLB 63 +#define VHOST_USER_F_PROTOCOL_FEATURES 30 + /* Generic structures common for any vhost based device. */ struct vhost_inflight { @@ -165,24 +168,26 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); * vhost_dev_start() - start the vhost device * @hdev: common vhost_dev structure * @vdev: the VirtIODevice structure + * @vrings: true to have vrings enabled in this call * * Starts the vhost device. From this point VirtIO feature negotiation * can start and the device can start processing VirtIO transactions. * * Return: 0 on success, < 0 on error. */ -int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev); +int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings); /** * vhost_dev_stop() - stop the vhost device * @hdev: common vhost_dev structure * @vdev: the VirtIODevice structure + * @vrings: true to have vrings disabled in this call * * Stop the vhost device. After the device is stopped the notifiers * can be disabled (@vhost_dev_disable_notifiers) and the device can * be torn down (@vhost_dev_cleanup). */ -void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev); +void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings); /** * DOC: vhost device configuration handling -- 2.27.0