Commit 5eb2347867 for qemu.org
commit 5eb2347867ee47b0a5a458adbb0973d99214906d
Author: Alexandr Moshkov <dtalexundeer@yandex-team.ru>
Date: Mon Aug 3 12:28:48 2026 +0500
vhost-user: add skip_drain param to do_vhost_virtqueue_stop
Currently do_vhost_virtqueue_stop always sends GET_VRING_BASE to the
back-end, which requires the back-end to drain all in-flight I/O before
stopping the vring.
Add a skip_drain parameter to do_vhost_virtqueue_stop and propagate it
up through vhost_virtqueue_stop, vhost_dev_stop and their callers.
The parameter will be used in a follow-up commit to send a new protocol
message that instructs the back-end to suspend in-flight I/O immediately
instead of draining it.
Signed-off-by: Alexandr Moshkov <dtalexundeer@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260803072853.2920007-2-dtalexundeer@yandex-team.ru>
diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
index c6069f4e5b..f1ca6bcd4e 100644
--- a/backends/cryptodev-vhost.c
+++ b/backends/cryptodev-vhost.c
@@ -109,7 +109,7 @@ static void
cryptodev_vhost_stop_one(CryptoDevBackendVhost *crypto,
VirtIODevice *dev)
{
- vhost_dev_stop(&crypto->dev, dev, false);
+ vhost_dev_stop(&crypto->dev, dev, false, false);
vhost_dev_disable_notifiers(&crypto->dev, dev);
}
diff --git a/backends/vhost-user.c b/backends/vhost-user.c
index 46dadb7480..de6b1ba267 100644
--- a/backends/vhost-user.c
+++ b/backends/vhost-user.c
@@ -108,7 +108,7 @@ vhost_user_backend_stop(VhostUserBackend *b)
return 0;
}
- ret = vhost_dev_stop(&b->dev, b->vdev, true);
+ ret = vhost_dev_stop(&b->dev, b->vdev, true, false);
if (k->set_guest_notifiers &&
(err = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false)) < 0) {
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 2e5b3ae1b1..c3e3c37f8c 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -238,7 +238,7 @@ static int vhost_user_blk_stop(VirtIODevice *vdev)
qemu_force_shutdown_requested();
ret = force_stop ? vhost_dev_force_stop(&s->dev, vdev, true) :
- vhost_dev_stop(&s->dev, vdev, true);
+ vhost_dev_stop(&s->dev, vdev, true, false);
err = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
if (err < 0) {
diff --git a/hw/display/vhost-user-media.c b/hw/display/vhost-user-media.c
index eaf99dc6a2..851af8ddc2 100644
--- a/hw/display/vhost-user-media.c
+++ b/hw/display/vhost-user-media.c
@@ -110,7 +110,7 @@ static void vu_media_stop(VirtIODevice *vdev)
return;
}
- vhost_dev_stop(&media->vhost_dev, vdev, true);
+ vhost_dev_stop(&media->vhost_dev, vdev, true, false);
ret = k->set_guest_notifiers(qbus->parent, media->vhost_dev.nvqs, false);
if (ret < 0) {
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 323d117735..6e05c995f1 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -384,7 +384,7 @@ fail:
if (net->nc->info->poll) {
net->nc->info->poll(net->nc, true);
}
- vhost_dev_stop(&net->dev, dev, false);
+ vhost_dev_stop(&net->dev, dev, false, false);
fail_start:
return r;
}
@@ -403,7 +403,7 @@ 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, false);
+ vhost_dev_stop(&net->dev, dev, false, false);
if (net->nc->info->stop) {
net->nc->info->stop(net->nc);
}
@@ -636,7 +636,8 @@ void vhost_net_virtqueue_reset(VirtIODevice *vdev, NetClientState *nc,
vhost_virtqueue_stop(&net->dev,
vdev,
net->dev.vqs + idx,
- net->dev.vq_index + idx);
+ net->dev.vq_index + idx,
+ false);
}
int vhost_net_virtqueue_restart(VirtIODevice *vdev, NetClientState *nc,
@@ -686,7 +687,7 @@ err_start:
assert(ret >= 0);
}
- vhost_dev_stop(&net->dev, vdev, false);
+ vhost_dev_stop(&net->dev, vdev, false, false);
return r;
}
diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c
index e19800a0bc..e546a6dc75 100644
--- a/hw/scsi/vhost-scsi-common.c
+++ b/hw/scsi/vhost-scsi-common.c
@@ -108,7 +108,7 @@ int vhost_scsi_common_stop(VHostSCSICommon *vsc)
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret = 0;
- ret = vhost_dev_stop(&vsc->dev, vdev, true);
+ ret = vhost_dev_stop(&vsc->dev, vdev, true, false);
if (k->set_guest_notifiers) {
int r = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index 6dc684ab09..7e5cc040e9 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -301,7 +301,7 @@ static void vhost_vdpa_device_stop(VirtIODevice *vdev)
return;
}
- vhost_dev_stop(&s->dev, vdev, false);
+ vhost_dev_stop(&s->dev, vdev, false, false);
ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
if (ret < 0) {
diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c
index 478ec68f09..1a377016e7 100644
--- a/hw/virtio/vhost-user-base.c
+++ b/hw/virtio/vhost-user-base.c
@@ -78,7 +78,7 @@ static int vub_stop(VirtIODevice *vdev)
return 0;
}
- ret = vhost_dev_stop(&vub->vhost_dev, vdev, true);
+ ret = vhost_dev_stop(&vub->vhost_dev, vdev, true, false);
err = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
if (err < 0) {
diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
index 209993918a..0d8842817a 100644
--- a/hw/virtio/vhost-user-fs.c
+++ b/hw/virtio/vhost-user-fs.c
@@ -111,7 +111,7 @@ static int vuf_stop(VirtIODevice *vdev)
return 0;
}
- ret = vhost_dev_stop(&fs->vhost_dev, vdev, true);
+ ret = vhost_dev_stop(&fs->vhost_dev, vdev, true, false);
err = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
if (err < 0) {
diff --git a/hw/virtio/vhost-user-scmi.c b/hw/virtio/vhost-user-scmi.c
index 02dc088ea9..c4692bd6aa 100644
--- a/hw/virtio/vhost-user-scmi.c
+++ b/hw/virtio/vhost-user-scmi.c
@@ -101,7 +101,7 @@ static int vu_scmi_stop(VirtIODevice *vdev)
return 0;
}
- ret = vhost_dev_stop(vhost_dev, vdev, true);
+ ret = vhost_dev_stop(vhost_dev, vdev, true, false);
err = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false);
if (err < 0) {
diff --git a/hw/virtio/vhost-vsock-common.c b/hw/virtio/vhost-vsock-common.c
index b79f4c9ce6..4ef037627b 100644
--- a/hw/virtio/vhost-vsock-common.c
+++ b/hw/virtio/vhost-vsock-common.c
@@ -106,7 +106,7 @@ int vhost_vsock_common_stop(VirtIODevice *vdev)
return 0;
}
- ret = vhost_dev_stop(&vvc->vhost_dev, vdev, true);
+ ret = vhost_dev_stop(&vvc->vhost_dev, vdev, true, false);
err = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
if (err < 0) {
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 52ea142bd4..48fe1805bb 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -23,6 +23,7 @@
#include "qemu/log.h"
#include "standard-headers/linux/vhost_types.h"
#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/vhost-user.h"
#include "hw/mem/memory-device.h"
#include "migration/blocker.h"
#include "migration/qemu-file-types.h"
@@ -1499,8 +1500,13 @@ fail:
static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
struct VirtIODevice *vdev,
struct vhost_virtqueue *vq,
- unsigned idx, bool force)
+ unsigned idx, bool force,
+ bool skip_drain)
{
+ if (skip_drain) {
+ assert(vhost_user_has_protocol_feature(dev,
+ VHOST_USER_PROTOCOL_F_GET_VRING_BASE_INFLIGHT));
+ }
int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx);
struct vhost_vring_state state = {
.index = vhost_vq_index,
@@ -1550,9 +1556,10 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
int vhost_virtqueue_stop(struct vhost_dev *dev,
struct VirtIODevice *vdev,
struct vhost_virtqueue *vq,
- unsigned idx)
+ unsigned idx,
+ bool skip_drain)
{
- return do_vhost_virtqueue_stop(dev, vdev, vq, idx, false);
+ return do_vhost_virtqueue_stop(dev, vdev, vq, idx, false, skip_drain);
}
static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev,
@@ -2307,7 +2314,8 @@ fail_vq:
vhost_virtqueue_stop(hdev,
vdev,
hdev->vqs + i,
- hdev->vq_index + i);
+ hdev->vq_index + i,
+ false);
}
fail_mem:
@@ -2322,7 +2330,7 @@ fail_features:
/* Host notifiers must be enabled at this point. */
static int do_vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev,
- bool vrings, bool force)
+ bool vrings, bool force, bool skip_drain)
{
int i;
int rc = 0;
@@ -2349,7 +2357,8 @@ static int do_vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev,
vdev,
hdev->vqs + i,
hdev->vq_index + i,
- force);
+ force,
+ skip_drain);
}
if (hdev->vhost_ops->vhost_reset_status) {
hdev->vhost_ops->vhost_reset_status(hdev);
@@ -2371,15 +2380,16 @@ static int do_vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev,
return rc;
}
-int vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings)
+int vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings,
+ bool skip_drain)
{
- return do_vhost_dev_stop(hdev, vdev, vrings, false);
+ return do_vhost_dev_stop(hdev, vdev, vrings, false, skip_drain);
}
int vhost_dev_force_stop(struct vhost_dev *hdev, VirtIODevice *vdev,
bool vrings)
{
- return do_vhost_dev_stop(hdev, vdev, vrings, true);
+ return do_vhost_dev_stop(hdev, vdev, vrings, true, false);
}
int vhost_net_set_backend(struct vhost_dev *hdev,
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 3db56433b6..0a322efec1 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -228,6 +228,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
* @hdev: common vhost_dev structure
* @vdev: the VirtIODevice structure
* @vrings: true to have vrings disabled in this call
+ * @skip_drain: true to notice back-end to skip draining all in-flight requests
*
* Stop the vhost device. After the device is stopped the notifiers
* can be disabled (@vhost_dev_disable_notifiers) and the device can
@@ -235,7 +236,8 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
*
* Return: 0 on success, != 0 on error when stopping dev.
*/
-int vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
+int vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings,
+ bool skip_drain);
/**
* vhost_dev_force_stop() - force stop the vhost device
@@ -396,7 +398,8 @@ int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
int vhost_virtqueue_start(struct vhost_dev *dev, struct VirtIODevice *vdev,
struct vhost_virtqueue *vq, unsigned idx);
int vhost_virtqueue_stop(struct vhost_dev *dev, struct VirtIODevice *vdev,
- struct vhost_virtqueue *vq, unsigned idx);
+ struct vhost_virtqueue *vq, unsigned idx,
+ bool skip_drain);
void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
void vhost_dev_free_inflight(struct vhost_inflight *inflight);