* [PATCH v4 00/23] vhost refactoring and fixes
@ 2026-01-19 18:52 Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 01/23] vhost-user: rework enabling vrings Vladimir Sementsov-Ogievskiy
` (22 more replies)
0 siblings, 23 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst; +Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin
Hi all. That's a preparation for vhost-user-blk backend-transfer
feature.
v4: rebase on master, and follow Michael's comments:
04: cover one more (new) dev->protocol-features access, keep r-bs
06: add r-b by Daniil
07: new
08: support virtio-ccw, drop r-b
11: rebase on changed code in master, drop r-bs
15: rebase on changed code in master, drop r-bs
16: rebase on changed code in master, drop r-bs
21: add macro VHOST_USER_CASE, drop r-bs
23: s/virtque/virtqueue/, keep r-bs
I also have dropped
[PATCH v3 18/23] vhost: introduce check_memslots() helper
as it was doubtful, and I'm not sure now, do I really need
it, and should it be done this way. Will look, when reworking
actual vhost-user-blk backend-transfer series on top of this.
And can't keep t-b of v3, I think.
Vladimir Sementsov-Ogievskiy (23):
vhost-user: rework enabling vrings
vhost: drop backend_features field
vhost-user: introduce vhost_user_has_protocol_feature() helper
vhost: move protocol_features to vhost_user
vhost-user-gpu: drop code duplication
vhost: make vhost_dev.features private
virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path
virtio: move common part of _set_guest_notifier to generic code
virtio: drop *_set_guest_notifier_fd_handler() helpers
vhost-user: keep QIOChannelSocket for backend channel
vhost: vhost_virtqueue_start(): fix failure path
vhost: make vhost_memory_unmap() null-safe
vhost: simplify calls to vhost_memory_unmap()
vhost: move vrings mapping to the top of vhost_virtqueue_start()
vhost: vhost_virtqueue_start(): drop extra local variables
vhost: final refactoring of vhost vrings map/unmap
vhost: simplify vhost_dev_init() error-path
vhost: move busyloop timeout initialization to vhost_virtqueue_init()
vhost: vhost_dev_init(): simplify features initialization
hw/virtio/virtio-bus: refactor virtio_bus_set_host_notifier()
vhost-user: make trace events more readable
vhost-user-blk: add some useful trace-points
vhost: add some useful trace-points
backends/cryptodev-vhost.c | 9 +-
hw/block/trace-events | 10 ++
hw/block/vhost-user-blk.c | 20 ++-
hw/display/vhost-user-gpu.c | 11 +-
hw/net/vhost_net.c | 35 ++---
hw/s390x/virtio-ccw.c | 34 ++---
hw/scsi/vhost-scsi.c | 1 -
hw/scsi/vhost-user-scsi.c | 1 -
hw/virtio/trace-events | 16 +-
hw/virtio/vdpa-dev.c | 3 +-
hw/virtio/vhost-user-base.c | 8 +-
hw/virtio/vhost-user.c | 258 ++++++++++++++++++++++-----------
hw/virtio/vhost.c | 238 +++++++++++++++---------------
hw/virtio/virtio-bus.c | 18 +--
hw/virtio/virtio-hmp-cmds.c | 2 -
hw/virtio/virtio-mmio.c | 41 +-----
hw/virtio/virtio-pci.c | 34 +----
hw/virtio/virtio-qmp.c | 12 +-
hw/virtio/virtio.c | 48 +++---
include/hw/virtio/vhost-user.h | 3 +
include/hw/virtio/vhost.h | 63 +++++---
include/hw/virtio/virtio-pci.h | 3 -
include/hw/virtio/virtio.h | 16 +-
net/vhost-vdpa.c | 7 +-
qapi/virtio.json | 3 -
25 files changed, 487 insertions(+), 407 deletions(-)
--
2.52.0
^ permalink raw reply [flat|nested] 37+ messages in thread
* [PATCH v4 01/23] vhost-user: rework enabling vrings
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 02/23] vhost: drop backend_features field Vladimir Sementsov-Ogievskiy
` (21 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz, Gonglei (Arei), zhenwei pi, Jason Wang
We call the handler almost the same way in three places:
- cryptodev-vhost.c
- vhost_net.c
- vhost.c
The only difference, is that in vhost.c we don't try to call the handler
for old vhost-user (when VHOST_USER_F_PROTOCOL_FEATURES is not supported).
cryptodev-vhost and vhost_net code will just fail in this case. Probably
they were developed only for newer vhost-user. Anyway, it doesn't seem
correct to rely on this error path, if these devices want to check,
that they don't communicate to old vhost-user protocol, they should
do that earlier.
Let's create the common helper, to call .vhost_set_vring_enable and
use in all three places. For vhost-user let's just always skip
enable/disable if it's unsupported.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
backends/cryptodev-vhost.c | 8 +-------
hw/net/vhost_net.c | 7 +------
hw/virtio/vhost-user.c | 7 ++++++-
hw/virtio/vhost.c | 21 ---------------------
include/hw/virtio/vhost.h | 9 +++++++++
5 files changed, 17 insertions(+), 35 deletions(-)
diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
index 943680a23a..abdfce33af 100644
--- a/backends/cryptodev-vhost.c
+++ b/backends/cryptodev-vhost.c
@@ -152,7 +152,6 @@ vhost_set_vring_enable(CryptoDevBackendClient *cc,
{
CryptoDevBackendVhost *crypto =
cryptodev_get_vhost(cc, b, queue);
- const VhostOps *vhost_ops;
cc->vring_enable = enable;
@@ -160,12 +159,7 @@ vhost_set_vring_enable(CryptoDevBackendClient *cc,
return 0;
}
- vhost_ops = crypto->dev.vhost_ops;
- if (vhost_ops->vhost_set_vring_enable) {
- return vhost_ops->vhost_set_vring_enable(&crypto->dev, enable);
- }
-
- return 0;
+ return vhost_dev_set_vring_enable(&crypto->dev, enable);
}
int cryptodev_vhost_start(VirtIODevice *dev, int total_queues)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index a8ee18a912..25e9f1fd24 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -587,7 +587,6 @@ VHostNetState *get_vhost_net(NetClientState *nc)
int vhost_net_set_vring_enable(NetClientState *nc, int enable)
{
VHostNetState *net = get_vhost_net(nc);
- const VhostOps *vhost_ops = net->dev.vhost_ops;
/*
* vhost-vdpa network devices need to enable dataplane virtqueues after
@@ -601,11 +600,7 @@ int vhost_net_set_vring_enable(NetClientState *nc, int enable)
nc->vring_enable = enable;
- if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
- return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
- }
-
- return 0;
+ return vhost_dev_set_vring_enable(&net->dev, enable);
}
int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 63fa9a1b4b..7615ae2a9b 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1235,7 +1235,12 @@ static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
int i;
if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
- return -EINVAL;
+ /*
+ * For vhost-user devices, if VHOST_USER_F_PROTOCOL_FEATURES has not
+ * been negotiated, the rings start directly in the enabled state,
+ * and can't be disabled.
+ */
+ return 0;
}
for (i = 0; i < dev->nvqs; ++i) {
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 31e9704cdc..29f2c75f1e 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -2022,27 +2022,6 @@ 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.
*
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 08bbb4dfe9..1ee639dd7e 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -215,6 +215,15 @@ static inline bool vhost_dev_is_started(struct vhost_dev *hdev)
return hdev->started;
}
+static inline int vhost_dev_set_vring_enable(struct vhost_dev *hdev, int enable)
+{
+ if (!hdev->vhost_ops->vhost_set_vring_enable) {
+ return 0;
+ }
+
+ return hdev->vhost_ops->vhost_set_vring_enable(hdev, enable);
+}
+
/**
* vhost_dev_start() - start the vhost device
* @hdev: common vhost_dev structure
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 02/23] vhost: drop backend_features field
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 01/23] vhost-user: rework enabling vrings Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 03/23] vhost-user: introduce vhost_user_has_protocol_feature() helper Vladimir Sementsov-Ogievskiy
` (20 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
devel, Markus Armbruster, Raphael Norwitz, Kevin Wolf,
Hanna Reitz, Jason Wang, Paolo Bonzini, Fam Zheng, Eric Blake,
open list:Block layer core
This field is mostly unused and sometimes confusing. We even have
a TODO-like comment to drop it, the comment is removed in this commit.
The field is used to held VHOST_USER_F_PROTOCOL_FEATURES for vhost-user
and/or VHOST_NET_F_VIRTIO_NET_HDR for vhost-net (which may be
vhost-user-net). But we can simply recalculate these two flags in place
from hdev->features, and from net-client for VHOST_NET_F_VIRTIO_NET_HDR.
Note: removing field from x-query-virtio-status result is incompatible
change. We can do it because the command is unstable.
Cc: devel@lists.libvirt.org
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Acked-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/block/vhost-user-blk.c | 1 -
hw/net/vhost_net.c | 26 ++++++++++++++------------
hw/scsi/vhost-scsi.c | 1 -
hw/scsi/vhost-user-scsi.c | 1 -
hw/virtio/vdpa-dev.c | 1 -
hw/virtio/vhost-user.c | 17 ++++++++---------
hw/virtio/virtio-hmp-cmds.c | 2 --
hw/virtio/virtio-qmp.c | 4 ----
include/hw/virtio/vhost.h | 7 -------
qapi/virtio.json | 3 ---
10 files changed, 22 insertions(+), 41 deletions(-)
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 4d81d2dc34..c8f7156ca6 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -348,7 +348,6 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
s->dev.nvqs = s->num_queues;
s->dev.vqs = s->vhost_vqs;
s->dev.vq_index = 0;
- s->dev.backend_features = 0;
vhost_dev_set_config_notifier(&s->dev, &blk_ops);
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 25e9f1fd24..fda90e231e 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -52,8 +52,14 @@ int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
void vhost_net_ack_features_ex(struct vhost_net *net, const uint64_t *features)
{
- virtio_features_copy(net->dev.acked_features_ex,
- net->dev.backend_features_ex);
+ virtio_features_clear(net->dev.acked_features_ex);
+ if (net->backend == -1) {
+ net->dev.acked_features =
+ net->dev.features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
+ } else if (!qemu_has_vnet_hdr(net->nc)) {
+ net->dev.acked_features = 1ULL << VHOST_NET_F_VIRTIO_NET_HDR;
+ }
+
vhost_ack_features_ex(&net->dev, net->feature_bits, features);
}
@@ -258,12 +264,9 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
if (r < 0) {
goto fail;
}
- net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
- ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
net->backend = r;
net->dev.protocol_features = 0;
} else {
- virtio_features_clear(net->dev.backend_features_ex);
net->dev.protocol_features = 0;
net->backend = -1;
@@ -284,13 +287,12 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
}
- if (virtio_features_andnot(missing_features,
- net->dev.backend_features_ex,
- net->dev.features_ex)) {
- fprintf(stderr, "vhost lacks feature mask 0x" VIRTIO_FEATURES_FMT
- " for backend\n", VIRTIO_FEATURES_PR(missing_features));
- goto fail;
- }
+ if (!qemu_has_vnet_hdr(options->net_backend) &&
+ (~net->dev.features & (1ULL << VHOST_NET_F_VIRTIO_NET_HDR))) {
+ fprintf(stderr, "vhost lacks feature mask 0x%llx for backend\n",
+ ~net->dev.features & (1ULL << VHOST_NET_F_VIRTIO_NET_HDR));
+ goto fail;
+ }
}
/* Set sane init value. Override when guest acks. */
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 699863cc10..859888fdba 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -275,7 +275,6 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp)
vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
vsc->dev.vqs = vqs;
vsc->dev.vq_index = 0;
- vsc->dev.backend_features = 0;
ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
VHOST_BACKEND_TYPE_KERNEL, 0, errp);
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index 3612897d4b..5070178dc2 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -159,7 +159,6 @@ static int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
vsc->dev.vqs = s->vhost_vqs;
vsc->dev.vq_index = 0;
- vsc->dev.backend_features = 0;
ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
errp);
diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index 4532d63653..06179e402e 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -104,7 +104,6 @@ static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp)
v->dev.vqs = vqs;
v->dev.vq_index = 0;
v->dev.vq_index_end = v->dev.nvqs;
- v->dev.backend_features = 0;
v->started = false;
ret = vhost_vdpa_get_iova_range(v->vhostfd, &iova_range);
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 7615ae2a9b..0ab1b14da5 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1470,14 +1470,15 @@ static int vhost_user_set_features(struct vhost_dev *dev,
int ret;
/*
- * We need to include any extra backend only feature bits that
- * might be needed by our device. Currently this includes the
- * VHOST_USER_F_PROTOCOL_FEATURES bit for enabling protocol
- * features.
+ * Don't lose VHOST_USER_F_PROTOCOL_FEATURES, which is vhost-user
+ * specific.
*/
- ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES,
- features | dev->backend_features,
- log_enabled);
+ if (virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
+ features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
+ }
+
+ ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features,
+ log_enabled);
if (virtio_has_feature(dev->protocol_features,
VHOST_USER_PROTOCOL_F_STATUS)) {
@@ -2197,8 +2198,6 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
(dev->config_ops && dev->config_ops->vhost_dev_config_notifier);
uint64_t protocol_features;
- dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
-
err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
&protocol_features);
if (err < 0) {
diff --git a/hw/virtio/virtio-hmp-cmds.c b/hw/virtio/virtio-hmp-cmds.c
index 1daae482d3..4bf9a3109d 100644
--- a/hw/virtio/virtio-hmp-cmds.c
+++ b/hw/virtio/virtio-hmp-cmds.c
@@ -176,8 +176,6 @@ void hmp_virtio_status(Monitor *mon, const QDict *qdict)
hmp_virtio_dump_features(mon, s->vhost_dev->features);
monitor_printf(mon, " Acked features:\n");
hmp_virtio_dump_features(mon, s->vhost_dev->acked_features);
- monitor_printf(mon, " Backend features:\n");
- hmp_virtio_dump_features(mon, s->vhost_dev->backend_features);
monitor_printf(mon, " Protocol features:\n");
hmp_virtio_dump_protocols(mon, s->vhost_dev->protocol_features);
}
diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
index 968299fda0..916972e331 100644
--- a/hw/virtio/virtio-qmp.c
+++ b/hw/virtio/virtio-qmp.c
@@ -780,8 +780,6 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
vdev->guest_features_ex);
status->host_features = qmp_decode_features(vdev->device_id,
vdev->host_features_ex);
- status->backend_features = qmp_decode_features(vdev->device_id,
- vdev->backend_features_ex);
switch (vdev->device_endian) {
case VIRTIO_DEVICE_ENDIAN_LITTLE:
@@ -822,8 +820,6 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
qmp_decode_features(vdev->device_id, hdev->features_ex);
status->vhost_dev->acked_features =
qmp_decode_features(vdev->device_id, hdev->acked_features_ex);
- status->vhost_dev->backend_features =
- qmp_decode_features(vdev->device_id, hdev->backend_features_ex);
status->vhost_dev->protocol_features =
qmp_decode_protocols(hdev->protocol_features);
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 1ee639dd7e..3e69e47833 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -100,16 +100,9 @@ struct vhost_dev {
*
* @features: available features provided by the backend
* @acked_features: final negotiated features with front-end driver
- *
- * @backend_features: this is used in a couple of places to either
- * store VHOST_USER_F_PROTOCOL_FEATURES to apply to
- * VHOST_USER_SET_FEATURES or VHOST_NET_F_VIRTIO_NET_HDR. Its
- * future use should be discouraged and the variable retired as
- * its easy to confuse with the VirtIO backend_features.
*/
VIRTIO_DECLARE_FEATURES(features);
VIRTIO_DECLARE_FEATURES(acked_features);
- VIRTIO_DECLARE_FEATURES(backend_features);
/**
* @protocol_features: is the vhost-user only feature set by
diff --git a/qapi/virtio.json b/qapi/virtio.json
index cd67c4f52e..53ddc6b6a4 100644
--- a/qapi/virtio.json
+++ b/qapi/virtio.json
@@ -85,8 +85,6 @@
#
# @acked-features: vhost_dev acked_features
#
-# @backend-features: vhost_dev backend_features
-#
# @protocol-features: vhost_dev protocol_features
#
# @max-queues: vhost_dev max_queues
@@ -106,7 +104,6 @@
'vq-index': 'int',
'features': 'VirtioDeviceFeatures',
'acked-features': 'VirtioDeviceFeatures',
- 'backend-features': 'VirtioDeviceFeatures',
'protocol-features': 'VhostDeviceProtocols',
'max-queues': 'uint64',
'backend-cap': 'uint64',
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 03/23] vhost-user: introduce vhost_user_has_protocol_feature() helper
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 01/23] vhost-user: rework enabling vrings Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 02/23] vhost: drop backend_features field Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 04/23] vhost: move protocol_features to vhost_user Vladimir Sementsov-Ogievskiy
` (19 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
Make all protocol feature checks in the same way.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/virtio/vhost-user.c | 120 +++++++++++++++++++++--------------------
1 file changed, 62 insertions(+), 58 deletions(-)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 0ab1b14da5..0832b8f26c 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -272,6 +272,12 @@ struct scrub_regions {
int fd_idx;
};
+static bool vhost_user_has_protocol_feature(struct vhost_dev *dev,
+ uint64_t feature)
+{
+ return virtio_has_feature(dev->protocol_features, feature);
+}
+
static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
{
struct vhost_user *u = dev->opaque;
@@ -435,8 +441,8 @@ static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
{
int fds[VHOST_USER_MAX_RAM_SLOTS];
size_t fd_num = 0;
- bool shmfd = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_LOG_SHMFD);
+ bool shmfd =
+ vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_LOG_SHMFD);
int ret;
VhostUserMsg msg = {
.hdr.request = VHOST_USER_SET_LOG_BASE,
@@ -1006,11 +1012,11 @@ static int vhost_user_set_mem_table(struct vhost_dev *dev,
int fds[VHOST_MEMORY_BASELINE_NREGIONS];
size_t fd_num = 0;
bool do_postcopy = u->postcopy_listen && u->postcopy_fd.handler;
- bool reply_supported = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK);
+ bool reply_supported =
+ vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
bool config_mem_slots =
- virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS);
+ vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS);
int ret;
if (do_postcopy) {
@@ -1058,8 +1064,9 @@ static int vhost_user_set_mem_table(struct vhost_dev *dev,
static int vhost_user_set_vring_endian(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
- bool cross_endian = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CROSS_ENDIAN);
+ bool cross_endian =
+ vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_CROSS_ENDIAN);
VhostUserMsg msg = {
.hdr.request = VHOST_USER_SET_VRING_ENDIAN,
.hdr.flags = VHOST_USER_VERSION,
@@ -1129,8 +1136,9 @@ static int vhost_user_write_sync(struct vhost_dev *dev, VhostUserMsg *msg,
int ret;
if (wait_for_reply) {
- bool reply_supported = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK);
+ bool reply_supported =
+ vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
if (reply_supported) {
msg->hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
}
@@ -1480,8 +1488,7 @@ static int vhost_user_set_features(struct vhost_dev *dev,
ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features,
log_enabled);
- if (virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_STATUS)) {
+ if (vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_STATUS)) {
if (!ret) {
return vhost_user_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
}
@@ -1535,8 +1542,8 @@ static int vhost_user_reset_device(struct vhost_dev *dev)
* Historically, reset was not implemented so only reset devices
* that are expecting it.
*/
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
return -ENOSYS;
}
@@ -1593,8 +1600,8 @@ static int vhost_user_backend_handle_vring_host_notifier(struct vhost_dev *dev,
void *addr;
char *name;
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) ||
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) ||
vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) {
return -EINVAL;
}
@@ -1892,13 +1899,13 @@ static int vhost_setup_backend_channel(struct vhost_dev *dev)
};
struct vhost_user *u = dev->opaque;
int sv[2], ret = 0;
- bool reply_supported = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK);
+ bool reply_supported =
+ vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
Error *local_err = NULL;
QIOChannel *ioc;
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_BACKEND_REQ)) {
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ)) {
return 0;
}
@@ -2146,8 +2153,8 @@ static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
switch (pnd->reason) {
case POSTCOPY_NOTIFY_PROBE:
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
/* TODO: Get the device name into this error somehow */
error_setg(errp,
"vhost-user backend not capable of postcopy");
@@ -2238,7 +2245,7 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
}
/* query the max queues we support if backend supports Multiple Queue */
- if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
+ if (vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_MQ)) {
err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
&dev->max_queues);
if (err < 0) {
@@ -2256,18 +2263,18 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
}
if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) &&
- !(virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_BACKEND_REQ) &&
- virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
+ !(vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ) &&
+ vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
error_setg(errp, "IOMMU support requires reply-ack and "
"backend-req protocol features.");
return -EINVAL;
}
/* get max memory regions if backend supports configurable RAM slots */
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS)) {
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS)) {
u->user->memory_slots = VHOST_MEMORY_BASELINE_NREGIONS;
} else {
err = vhost_user_get_max_memslots(dev, &ram_slots);
@@ -2289,8 +2296,8 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
}
if (dev->migration_blocker == NULL &&
- !virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
+ !vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
error_setg(&dev->migration_blocker,
"Migration disabled: vhost-user backend lacks "
"VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
@@ -2359,8 +2366,8 @@ static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
{
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
- return virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_LOG_SHMFD);
+ return vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_LOG_SHMFD);
}
static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
@@ -2375,8 +2382,7 @@ static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
}
/* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
- if (virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_RARP)) {
+ if (vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_RARP)) {
msg.hdr.request = VHOST_USER_SEND_RARP;
msg.hdr.flags = VHOST_USER_VERSION;
memcpy((char *)&msg.payload.u64, mac_addr, 6);
@@ -2390,11 +2396,11 @@ static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu)
{
VhostUserMsg msg;
- bool reply_supported = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK);
+ bool reply_supported =
+ vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
int ret;
- if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))) {
+ if (!vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_NET_MTU)) {
return 0;
}
@@ -2454,8 +2460,7 @@ static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
.hdr.size = VHOST_USER_CONFIG_HDR_SIZE + config_len,
};
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CONFIG)) {
+ if (!vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_CONFIG)) {
error_setg(errp, "VHOST_USER_PROTOCOL_F_CONFIG not supported");
return -EINVAL;
}
@@ -2498,8 +2503,8 @@ static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *data,
{
int ret;
uint8_t *p;
- bool reply_supported = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK);
+ bool reply_supported =
+ vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
VhostUserMsg msg = {
.hdr.request = VHOST_USER_SET_CONFIG,
@@ -2507,8 +2512,7 @@ static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *data,
.hdr.size = VHOST_USER_CONFIG_HDR_SIZE + size,
};
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CONFIG)) {
+ if (!vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_CONFIG)) {
return -ENOTSUP;
}
@@ -2543,8 +2547,9 @@ static int vhost_user_crypto_create_session(struct vhost_dev *dev,
uint64_t *session_id)
{
int ret;
- bool crypto_session = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
+ bool crypto_session =
+ vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
CryptoDevBackendSessionInfo *backend_info = session_info;
VhostUserMsg msg = {
.hdr.request = VHOST_USER_CREATE_CRYPTO_SESSION,
@@ -2645,8 +2650,9 @@ static int
vhost_user_crypto_close_session(struct vhost_dev *dev, uint64_t session_id)
{
int ret;
- bool crypto_session = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
+ bool crypto_session =
+ vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
VhostUserMsg msg = {
.hdr.request = VHOST_USER_CLOSE_CRYPTO_SESSION,
.hdr.flags = VHOST_USER_VERSION,
@@ -2691,8 +2697,8 @@ static int vhost_user_get_inflight_fd(struct vhost_dev *dev,
.hdr.size = sizeof(msg.payload.inflight),
};
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
return 0;
}
@@ -2759,8 +2765,8 @@ static int vhost_user_set_inflight_fd(struct vhost_dev *dev,
.hdr.size = sizeof(msg.payload.inflight),
};
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ if (!vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
return 0;
}
@@ -2859,8 +2865,7 @@ void vhost_user_async_close(DeviceState *d,
static int vhost_user_dev_start(struct vhost_dev *dev, bool started)
{
- if (!virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_STATUS)) {
+ if (!vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_STATUS)) {
return 0;
}
@@ -2885,16 +2890,15 @@ static void vhost_user_reset_status(struct vhost_dev *dev)
return;
}
- if (virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_STATUS)) {
+ if (vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_STATUS)) {
vhost_user_set_status(dev, 0);
}
}
static bool vhost_user_supports_device_state(struct vhost_dev *dev)
{
- return virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_DEVICE_STATE);
+ return vhost_user_has_protocol_feature(
+ dev, VHOST_USER_PROTOCOL_F_DEVICE_STATE);
}
static int vhost_user_set_device_state_fd(struct vhost_dev *dev,
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 04/23] vhost: move protocol_features to vhost_user
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (2 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 03/23] vhost-user: introduce vhost_user_has_protocol_feature() helper Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 05/23] vhost-user-gpu: drop code duplication Vladimir Sementsov-Ogievskiy
` (18 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz, Gonglei (Arei), zhenwei pi, Jason Wang
As comment says: it's only for vhost-user. So, let's move it
to corresponding vhost backend realization.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
backends/cryptodev-vhost.c | 1 -
hw/net/vhost_net.c | 2 --
hw/virtio/vhost-user.c | 30 +++++++++++++++++++++++++-----
hw/virtio/virtio-qmp.c | 6 ++++--
include/hw/virtio/vhost-user.h | 3 +++
include/hw/virtio/vhost.h | 8 --------
6 files changed, 32 insertions(+), 18 deletions(-)
diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
index abdfce33af..c6069f4e5b 100644
--- a/backends/cryptodev-vhost.c
+++ b/backends/cryptodev-vhost.c
@@ -60,7 +60,6 @@ cryptodev_vhost_init(
crypto->cc = options->cc;
- crypto->dev.protocol_features = 0;
crypto->backend = -1;
/* vhost-user needs vq_index to initiate a specific queue pair */
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index fda90e231e..ca19983126 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -265,9 +265,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
goto fail;
}
net->backend = r;
- net->dev.protocol_features = 0;
} else {
- net->dev.protocol_features = 0;
net->backend = -1;
/* vhost-user needs vq_index to initiate a specific queue pair */
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 0832b8f26c..133a39f7a6 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -11,6 +11,7 @@
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/virtio/virtio-dmabuf.h"
+#include "hw/virtio/virtio-qmp.h"
#include "hw/virtio/vhost.h"
#include "hw/virtio/virtio-crypto.h"
#include "hw/virtio/vhost-user.h"
@@ -264,6 +265,14 @@ struct vhost_user {
/* Our current regions */
int num_shadow_regions;
struct vhost_memory_region shadow_regions[VHOST_USER_MAX_RAM_SLOTS];
+
+ /**
+ * @protocol_features: the vhost-user protocol feature set by
+ * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
+ * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
+ * by the backend (see @features).
+ */
+ uint64_t protocol_features;
};
struct scrub_regions {
@@ -275,7 +284,8 @@ struct scrub_regions {
static bool vhost_user_has_protocol_feature(struct vhost_dev *dev,
uint64_t feature)
{
- return virtio_has_feature(dev->protocol_features, feature);
+ struct vhost_user *u = dev->opaque;
+ return virtio_has_feature(u->protocol_features, feature);
}
static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
@@ -1343,8 +1353,8 @@ static int vhost_set_vring_file(struct vhost_dev *dev,
int ret;
int fds[VHOST_USER_MAX_RAM_SLOTS];
size_t fd_num = 0;
- bool reply_supported = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_REPLY_ACK);
+ bool reply_supported =
+ vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
VhostUserMsg msg = {
.hdr.request = request,
.hdr.flags = VHOST_USER_VERSION,
@@ -2237,8 +2247,8 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
}
/* final set of protocol features */
- dev->protocol_features = protocol_features;
- err = vhost_user_set_protocol_features(dev, dev->protocol_features);
+ u->protocol_features = protocol_features;
+ err = vhost_user_set_protocol_features(dev, u->protocol_features);
if (err < 0) {
error_setg_errno(errp, EPROTO, "vhost_backend_init failed");
return -EPROTO;
@@ -3029,6 +3039,16 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
return 0;
}
+void vhost_user_qmp_status(struct vhost_dev *dev, VirtioStatus *status)
+{
+ struct vhost_user *u = dev->opaque;
+
+ assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
+
+ status->vhost_dev->protocol_features =
+ qmp_decode_protocols(u->protocol_features);
+}
+
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_backend_init,
diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
index 916972e331..5e42b7b540 100644
--- a/hw/virtio/virtio-qmp.c
+++ b/hw/virtio/virtio-qmp.c
@@ -821,12 +821,14 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
status->vhost_dev->acked_features =
qmp_decode_features(vdev->device_id, hdev->acked_features_ex);
- status->vhost_dev->protocol_features =
- qmp_decode_protocols(hdev->protocol_features);
status->vhost_dev->max_queues = hdev->max_queues;
status->vhost_dev->backend_cap = hdev->backend_cap;
status->vhost_dev->log_enabled = hdev->log_enabled;
status->vhost_dev->log_size = hdev->log_size;
+
+ if (hdev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) {
+ vhost_user_qmp_status(hdev, status);
+ }
}
return status;
diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
index 55d5725ef8..ea9d308f4c 100644
--- a/include/hw/virtio/vhost-user.h
+++ b/include/hw/virtio/vhost-user.h
@@ -10,6 +10,7 @@
#include "chardev/char-fe.h"
#include "hw/virtio/virtio.h"
+#include "qapi/qapi-types-virtio.h"
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
@@ -111,4 +112,6 @@ void vhost_user_async_close(DeviceState *d,
CharFrontend *chardev, struct vhost_dev *vhost,
vu_async_close_fn cb);
+void vhost_user_qmp_status(struct vhost_dev *dev, VirtioStatus *status);
+
#endif
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 3e69e47833..e308bc4556 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -104,14 +104,6 @@ struct vhost_dev {
VIRTIO_DECLARE_FEATURES(features);
VIRTIO_DECLARE_FEATURES(acked_features);
- /**
- * @protocol_features: is the vhost-user only feature set by
- * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
- * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
- * by the backend (see @features).
- */
- uint64_t protocol_features;
-
uint64_t max_queues;
uint64_t backend_cap;
/* @started: is the vhost device started? */
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 05/23] vhost-user-gpu: drop code duplication
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (3 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 04/23] vhost: move protocol_features to vhost_user Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 06/23] vhost: make vhost_dev.features private Vladimir Sementsov-Ogievskiy
` (17 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Philippe Mathieu-Daudé, Raphael Norwitz,
Marc-André Lureau
Obviously, this duplicated fragment doesn't make any sense.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/display/vhost-user-gpu.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
index 3f6fb7a803..8911b2a72f 100644
--- a/hw/display/vhost-user-gpu.c
+++ b/hw/display/vhost-user-gpu.c
@@ -644,10 +644,6 @@ vhost_user_gpu_device_realize(DeviceState *qdev, Error **errp)
VIRTIO_GPU_F_RESOURCE_UUID)) {
g->parent_obj.conf.flags |= 1 << VIRTIO_GPU_FLAG_RESOURCE_UUID_ENABLED;
}
- if (virtio_has_feature(g->vhost->dev.features,
- VIRTIO_GPU_F_RESOURCE_UUID)) {
- g->parent_obj.conf.flags |= 1 << VIRTIO_GPU_FLAG_RESOURCE_UUID_ENABLED;
- }
if (!virtio_gpu_base_device_realize(qdev, NULL, NULL, errp)) {
return;
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 06/23] vhost: make vhost_dev.features private
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (4 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 05/23] vhost-user-gpu: drop code duplication Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path Vladimir Sementsov-Ogievskiy
` (16 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Marc-André Lureau, Jason Wang, Alex Bennée
It's hard to control where and how do we use this field. Let's
cover all usages by getters/setters, and keep direct access to the
field only in vhost.c. It will help to control migration of this
field in further commits.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/display/vhost-user-gpu.c | 7 +++----
hw/net/vhost_net.c | 18 ++++++++---------
hw/virtio/vdpa-dev.c | 2 +-
hw/virtio/vhost-user-base.c | 8 ++++++--
hw/virtio/vhost-user.c | 4 ++--
hw/virtio/vhost.c | 6 +++---
hw/virtio/virtio-qmp.c | 2 +-
include/hw/virtio/vhost.h | 39 +++++++++++++++++++++++++++++++++++--
net/vhost-vdpa.c | 7 +++----
9 files changed, 65 insertions(+), 28 deletions(-)
diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
index 8911b2a72f..3566e49a1a 100644
--- a/hw/display/vhost-user-gpu.c
+++ b/hw/display/vhost-user-gpu.c
@@ -631,17 +631,16 @@ vhost_user_gpu_device_realize(DeviceState *qdev, Error **errp)
/* existing backend may send DMABUF, so let's add that requirement */
g->parent_obj.conf.flags |= 1 << VIRTIO_GPU_FLAG_DMABUF_ENABLED;
- if (virtio_has_feature(g->vhost->dev.features, VIRTIO_GPU_F_VIRGL)) {
+ if (vhost_dev_has_feature(&g->vhost->dev, VIRTIO_GPU_F_VIRGL)) {
g->parent_obj.conf.flags |= 1 << VIRTIO_GPU_FLAG_VIRGL_ENABLED;
}
- if (virtio_has_feature(g->vhost->dev.features, VIRTIO_GPU_F_EDID)) {
+ if (vhost_dev_has_feature(&g->vhost->dev, VIRTIO_GPU_F_EDID)) {
g->parent_obj.conf.flags |= 1 << VIRTIO_GPU_FLAG_EDID_ENABLED;
} else {
error_report("EDID requested but the backend doesn't support it.");
g->parent_obj.conf.flags &= ~(1 << VIRTIO_GPU_FLAG_EDID_ENABLED);
}
- if (virtio_has_feature(g->vhost->dev.features,
- VIRTIO_GPU_F_RESOURCE_UUID)) {
+ if (vhost_dev_has_feature(&g->vhost->dev, VIRTIO_GPU_F_RESOURCE_UUID)) {
g->parent_obj.conf.flags |= 1 << VIRTIO_GPU_FLAG_RESOURCE_UUID_ENABLED;
}
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index ca19983126..323d117735 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -54,8 +54,8 @@ void vhost_net_ack_features_ex(struct vhost_net *net, const uint64_t *features)
{
virtio_features_clear(net->dev.acked_features_ex);
if (net->backend == -1) {
- net->dev.acked_features =
- net->dev.features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
+ net->dev.acked_features = (vhost_dev_features(&net->dev) &
+ (1ULL << VHOST_USER_F_PROTOCOL_FEATURES));
} else if (!qemu_has_vnet_hdr(net->nc)) {
net->dev.acked_features = 1ULL << VHOST_NET_F_VIRTIO_NET_HDR;
}
@@ -282,15 +282,15 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
if (backend_kernel) {
if (!qemu_has_vnet_hdr_len(options->net_backend,
sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
- net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
+ vhost_dev_clear_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
}
if (!qemu_has_vnet_hdr(options->net_backend) &&
- (~net->dev.features & (1ULL << VHOST_NET_F_VIRTIO_NET_HDR))) {
- fprintf(stderr, "vhost lacks feature mask 0x%llx for backend\n",
- ~net->dev.features & (1ULL << VHOST_NET_F_VIRTIO_NET_HDR));
- goto fail;
- }
+ !vhost_dev_has_feature(&net->dev, VHOST_NET_F_VIRTIO_NET_HDR)) {
+ fprintf(stderr, "vhost lacks VHOST_NET_F_VIRTIO_NET_HDR "
+ "feature for backend\n");
+ goto fail;
+ }
}
/* Set sane init value. Override when guest acks. */
@@ -298,7 +298,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
virtio_features_from_u64(features,
options->get_acked_features(net->nc));
if (virtio_features_andnot(missing_features, features,
- net->dev.features_ex)) {
+ vhost_dev_features_ex(&net->dev))) {
fprintf(stderr, "vhost lacks feature mask 0x" VIRTIO_FEATURES_FMT
" for backend\n", VIRTIO_FEATURES_PR(missing_features));
goto fail;
diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index 06179e402e..94188d37bb 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -224,7 +224,7 @@ static uint64_t vhost_vdpa_device_get_features(VirtIODevice *vdev,
Error **errp)
{
VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
- uint64_t backend_features = s->dev.features;
+ uint64_t backend_features = vhost_dev_features(&s->dev);
if (!virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM)) {
virtio_clear_feature(&backend_features, VIRTIO_F_IOMMU_PLATFORM);
diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c
index 01ab9ca56b..5bbf4a7367 100644
--- a/hw/virtio/vhost-user-base.c
+++ b/hw/virtio/vhost-user-base.c
@@ -118,9 +118,13 @@ static uint64_t vub_get_features(VirtIODevice *vdev,
uint64_t requested_features, Error **errp)
{
VHostUserBase *vub = VHOST_USER_BASE(vdev);
+ uint64_t backend_features = vhost_dev_features(&vub->vhost_dev);
+
/* This should be set when the vhost connection initialises */
- g_assert(vub->vhost_dev.features);
- return vub->vhost_dev.features & ~(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
+ g_assert(backend_features);
+ virtio_clear_feature(&backend_features, VHOST_USER_F_PROTOCOL_FEATURES);
+
+ return backend_features;
}
/*
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 133a39f7a6..6b79f50043 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1252,7 +1252,7 @@ static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
{
int i;
- if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
+ if (!vhost_dev_has_feature(dev, VHOST_USER_F_PROTOCOL_FEATURES)) {
/*
* For vhost-user devices, if VHOST_USER_F_PROTOCOL_FEATURES has not
* been negotiated, the rings start directly in the enabled state,
@@ -1491,7 +1491,7 @@ static int vhost_user_set_features(struct vhost_dev *dev,
* Don't lose VHOST_USER_F_PROTOCOL_FEATURES, which is vhost-user
* specific.
*/
- if (virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
+ if (vhost_dev_has_feature(dev, VHOST_USER_F_PROTOCOL_FEATURES)) {
features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
}
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 29f2c75f1e..40440c6d68 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1612,7 +1612,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
}
}
- virtio_features_copy(hdev->features_ex, features);
+ virtio_features_copy(hdev->_features_ex, features);
hdev->memory_listener = (MemoryListener) {
.name = "vhost",
@@ -1635,7 +1635,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
};
if (hdev->migration_blocker == NULL) {
- if (!virtio_has_feature_ex(hdev->features_ex, VHOST_F_LOG_ALL)) {
+ if (!vhost_dev_has_feature_ex(hdev, VHOST_F_LOG_ALL)) {
error_setg(&hdev->migration_blocker,
"Migration disabled: vhost lacks VHOST_F_LOG_ALL feature.");
} else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) {
@@ -1909,7 +1909,7 @@ void vhost_get_features_ex(struct vhost_dev *hdev,
const int *bit = feature_bits;
while (*bit != VHOST_INVALID_FEATURE_BIT) {
- if (!virtio_has_feature_ex(hdev->features_ex, *bit)) {
+ if (!vhost_dev_has_feature_ex(hdev, *bit)) {
virtio_clear_feature_ex(features, *bit);
}
bit++;
diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
index 5e42b7b540..f0c15ba27c 100644
--- a/hw/virtio/virtio-qmp.c
+++ b/hw/virtio/virtio-qmp.c
@@ -817,7 +817,7 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
status->vhost_dev->nvqs = hdev->nvqs;
status->vhost_dev->vq_index = hdev->vq_index;
status->vhost_dev->features =
- qmp_decode_features(vdev->device_id, hdev->features_ex);
+ qmp_decode_features(vdev->device_id, vhost_dev_features_ex(hdev));
status->vhost_dev->acked_features =
qmp_decode_features(vdev->device_id, hdev->acked_features_ex);
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index e308bc4556..1ba1af1d86 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -98,10 +98,11 @@ struct vhost_dev {
* offered by a backend which may be a subset of the total
* features eventually offered to the guest.
*
- * @features: available features provided by the backend
+ * @_features: available features provided by the backend, private,
+ * direct access only in vhost.h/vhost.c
* @acked_features: final negotiated features with front-end driver
*/
- VIRTIO_DECLARE_FEATURES(features);
+ VIRTIO_DECLARE_FEATURES(_features);
VIRTIO_DECLARE_FEATURES(acked_features);
uint64_t max_queues;
@@ -403,6 +404,40 @@ int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
struct vhost_inflight *inflight);
bool vhost_dev_has_iommu(struct vhost_dev *dev);
+static inline bool vhost_dev_has_feature(struct vhost_dev *dev,
+ uint64_t feature)
+{
+ return virtio_has_feature(dev->_features, feature);
+}
+
+static inline bool vhost_dev_has_feature_ex(struct vhost_dev *dev,
+ uint64_t feature)
+{
+ return virtio_has_feature_ex(dev->_features_ex, feature);
+}
+
+static inline uint64_t vhost_dev_features(struct vhost_dev *dev)
+{
+ return dev->_features;
+}
+
+static inline const uint64_t *vhost_dev_features_ex(struct vhost_dev *dev)
+{
+ return dev->_features_ex;
+}
+
+static inline void vhost_dev_clear_feature(struct vhost_dev *dev,
+ uint64_t feature)
+{
+ virtio_clear_feature(&dev->_features, feature);
+}
+
+static inline void vhost_dev_clear_feature_ex(struct vhost_dev *dev,
+ uint64_t feature)
+{
+ virtio_clear_feature_ex(dev->_features_ex, feature);
+}
+
#ifdef CONFIG_VHOST
int vhost_reset_device(struct vhost_dev *hdev);
#else
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 74d26a9497..0af0d3bdd3 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -256,15 +256,14 @@ static bool vhost_vdpa_get_vnet_hash_supported_types(NetClientState *nc,
{
assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
- uint64_t features = s->vhost_vdpa.dev->features;
int fd = s->vhost_vdpa.shared->device_fd;
struct {
struct vhost_vdpa_config hdr;
uint32_t supported_hash_types;
} config;
- if (!virtio_has_feature(features, VIRTIO_NET_F_HASH_REPORT) &&
- !virtio_has_feature(features, VIRTIO_NET_F_RSS)) {
+ if (!vhost_dev_has_feature(s->vhost_vdpa.dev, VIRTIO_NET_F_HASH_REPORT) &&
+ !vhost_dev_has_feature(s->vhost_vdpa.dev, VIRTIO_NET_F_RSS)) {
return false;
}
@@ -585,7 +584,7 @@ static int vhost_vdpa_net_cvq_start(NetClientState *nc)
* If we early return in these cases SVQ will not be enabled. The migration
* will be blocked as long as vhost-vdpa backends will not offer _F_LOG.
*/
- if (!vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) {
+ if (!vhost_vdpa_net_valid_svq_features(vhost_dev_features(v->dev), NULL)) {
return 0;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (5 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 06/23] vhost: make vhost_dev.features private Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-20 7:30 ` Thomas Huth
` (2 more replies)
2026-01-19 18:52 ` [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code Vladimir Sementsov-Ogievskiy
` (15 subsequent siblings)
22 siblings, 3 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Cornelia Huck, Halil Pasic, Eric Farman, Thomas Huth,
Richard Henderson, Ilya Leoshkevich, David Hildenbrand,
Christian Borntraeger, Matthew Rosato, open list:virtio-ccw
We leak notifier initialization on that failure path. Let's
cleanup it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
hw/s390x/virtio-ccw.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 6855e20d09..ba55bf4fe9 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1038,6 +1038,7 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
if (r) {
virtio_queue_set_guest_notifier_fd_handler(vq, false,
with_irqfd);
+ event_notifier_cleanup(notifier);
return r;
}
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (6 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-20 21:20 ` Eric Farman
2026-01-23 23:06 ` Halil Pasic
2026-01-19 18:52 ` [PATCH v4 09/23] virtio: drop *_set_guest_notifier_fd_handler() helpers Vladimir Sementsov-Ogievskiy
` (14 subsequent siblings)
22 siblings, 2 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Cornelia Huck, Halil Pasic, Eric Farman, Richard Henderson,
Ilya Leoshkevich, David Hildenbrand, Thomas Huth,
Christian Borntraeger, Matthew Rosato, open list:virtio-ccw
virtio-pci, virtio-mmio and virtio-ccw handle config notifier equally
but with different code (mmio adds a separate function, when pci use
common function). Let's chose the more compact way (pci) and reuse it
for mmio.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
hw/s390x/virtio-ccw.c | 35 ++++++++++++-------------
hw/virtio/virtio-mmio.c | 41 +++++------------------------
hw/virtio/virtio-pci.c | 34 +++---------------------
hw/virtio/virtio.c | 48 +++++++++++++++++++++++++++++++---
include/hw/virtio/virtio-pci.h | 3 ---
include/hw/virtio/virtio.h | 16 +++++++++---
6 files changed, 84 insertions(+), 93 deletions(-)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index ba55bf4fe9..f99d1e7cd8 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1025,20 +1025,27 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
VirtQueue *vq = virtio_get_queue(vdev, n);
EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+ int r;
- if (assign) {
- int r = event_notifier_init(notifier, 0);
-
- if (r < 0) {
- return r;
+ if (!assign) {
+ if (k->guest_notifier_mask && vdev->use_guest_notifier_mask) {
+ k->guest_notifier_mask(vdev, n, true);
}
- virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
+ if (with_irqfd) {
+ virtio_ccw_remove_irqfd(dev, n);
+ }
+ }
+
+ r = virtio_queue_set_guest_notifier(vdev, n, assign, with_irqfd);
+ if (r < 0) {
+ return r;
+ }
+
+ if (assign) {
if (with_irqfd) {
r = virtio_ccw_add_irqfd(dev, n);
if (r) {
- virtio_queue_set_guest_notifier_fd_handler(vq, false,
- with_irqfd);
- event_notifier_cleanup(notifier);
+ virtio_queue_set_guest_notifier(vdev, n, false, with_irqfd);
return r;
}
}
@@ -1054,16 +1061,8 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
k->guest_notifier_pending(vdev, n)) {
event_notifier_set(notifier);
}
- } else {
- if (k->guest_notifier_mask && vdev->use_guest_notifier_mask) {
- k->guest_notifier_mask(vdev, n, true);
- }
- if (with_irqfd) {
- virtio_ccw_remove_irqfd(dev, n);
- }
- virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
- event_notifier_cleanup(notifier);
}
+
return 0;
}
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 0b0412b22f..b41c3614be 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -670,18 +670,11 @@ static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
- VirtQueue *vq = virtio_get_queue(vdev, n);
- EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
+ int r;
- if (assign) {
- int r = event_notifier_init(notifier, 0);
- if (r < 0) {
- return r;
- }
- virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
- } else {
- virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
- event_notifier_cleanup(notifier);
+ r = virtio_queue_set_guest_notifier(vdev, n, assign, with_irqfd);
+ if (r < 0) {
+ return r;
}
if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
@@ -690,30 +683,7 @@ static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
return 0;
}
-static int virtio_mmio_set_config_guest_notifier(DeviceState *d, bool assign,
- bool with_irqfd)
-{
- VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
- VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
- VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
- EventNotifier *notifier = virtio_config_get_guest_notifier(vdev);
- int r = 0;
- if (assign) {
- r = event_notifier_init(notifier, 0);
- if (r < 0) {
- return r;
- }
- virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
- } else {
- virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
- event_notifier_cleanup(notifier);
- }
- if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
- vdc->guest_notifier_mask(vdev, VIRTIO_CONFIG_IRQ_IDX, !assign);
- }
- return r;
-}
static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
bool assign)
{
@@ -735,7 +705,8 @@ static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
goto assign_error;
}
}
- r = virtio_mmio_set_config_guest_notifier(d, assign, with_irqfd);
+ r = virtio_mmio_set_guest_notifier(d, VIRTIO_CONFIG_IRQ_IDX, assign,
+ with_irqfd);
if (r < 0) {
goto assign_error;
}
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index b273eb2691..e7d5e19b32 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1208,43 +1208,17 @@ static void virtio_pci_vector_poll(PCIDevice *dev,
}
}
-void virtio_pci_set_guest_notifier_fd_handler(VirtIODevice *vdev, VirtQueue *vq,
- int n, bool assign,
- bool with_irqfd)
-{
- if (n == VIRTIO_CONFIG_IRQ_IDX) {
- virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
- } else {
- virtio_queue_set_guest_notifier_fd_handler(vq, assign, with_irqfd);
- }
-}
-
static int virtio_pci_set_guest_notifier(DeviceState *d, int n, bool assign,
bool with_irqfd)
{
VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
- VirtQueue *vq = NULL;
- EventNotifier *notifier = NULL;
+ int r;
- if (n == VIRTIO_CONFIG_IRQ_IDX) {
- notifier = virtio_config_get_guest_notifier(vdev);
- } else {
- vq = virtio_get_queue(vdev, n);
- notifier = virtio_queue_get_guest_notifier(vq);
- }
-
- if (assign) {
- int r = event_notifier_init(notifier, 0);
- if (r < 0) {
- return r;
- }
- virtio_pci_set_guest_notifier_fd_handler(vdev, vq, n, true, with_irqfd);
- } else {
- virtio_pci_set_guest_notifier_fd_handler(vdev, vq, n, false,
- with_irqfd);
- event_notifier_cleanup(notifier);
+ r = virtio_queue_set_guest_notifier(vdev, n, assign, with_irqfd);
+ if (r < 0) {
+ return r;
}
if (!msix_enabled(&proxy->pci_dev) &&
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 3dc9423eae..ea43ea620c 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3828,8 +3828,10 @@ static void virtio_config_guest_notifier_read(EventNotifier *n)
virtio_notify_config(vdev);
}
}
-void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
- bool with_irqfd)
+
+static void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq,
+ bool assign,
+ bool with_irqfd)
{
if (assign && !with_irqfd) {
event_notifier_set_handler(&vq->guest_notifier,
@@ -3844,7 +3846,7 @@ void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
}
}
-void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
+static void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
bool assign, bool with_irqfd)
{
EventNotifier *n;
@@ -3861,6 +3863,46 @@ void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
}
}
+static void virtio_pci_set_guest_notifier_fd_handler(VirtIODevice *vdev,
+ VirtQueue *vq,
+ int n, bool assign,
+ bool with_irqfd)
+{
+ if (n == VIRTIO_CONFIG_IRQ_IDX) {
+ virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
+ } else {
+ virtio_queue_set_guest_notifier_fd_handler(vq, assign, with_irqfd);
+ }
+}
+
+int virtio_queue_set_guest_notifier(VirtIODevice *vdev, int n, bool assign,
+ bool with_irqfd)
+{
+ VirtQueue *vq = NULL;
+ EventNotifier *notifier = NULL;
+
+ if (n == VIRTIO_CONFIG_IRQ_IDX) {
+ notifier = virtio_config_get_guest_notifier(vdev);
+ } else {
+ vq = virtio_get_queue(vdev, n);
+ notifier = virtio_queue_get_guest_notifier(vq);
+ }
+
+ if (assign) {
+ int r = event_notifier_init(notifier, 0);
+ if (r < 0) {
+ return r;
+ }
+ virtio_pci_set_guest_notifier_fd_handler(vdev, vq, n, true, with_irqfd);
+ } else {
+ virtio_pci_set_guest_notifier_fd_handler(vdev, vq, n, false,
+ with_irqfd);
+ event_notifier_cleanup(notifier);
+ }
+
+ return 0;
+}
+
EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq)
{
return &vq->guest_notifier;
diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
index 639752977e..2a5b65f374 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -263,9 +263,6 @@ void virtio_pci_types_register(const VirtioPCIDeviceTypeInfo *t);
* @fixed_queues.
*/
unsigned virtio_pci_optimal_num_queues(unsigned fixed_queues);
-void virtio_pci_set_guest_notifier_fd_handler(VirtIODevice *vdev, VirtQueue *vq,
- int n, bool assign,
- bool with_irqfd);
int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy, uint8_t bar, uint64_t offset,
uint64_t length, uint8_t id);
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 27cd98d2fe..25ef7c9dff 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -420,8 +420,6 @@ void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
uint16_t virtio_get_queue_index(VirtQueue *vq);
EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
-void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
- bool with_irqfd);
int virtio_device_start_ioeventfd(VirtIODevice *vdev);
int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
void virtio_device_release_ioeventfd(VirtIODevice *vdev);
@@ -435,8 +433,18 @@ void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev);
-void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
- bool assign, bool with_irqfd);
+
+/**
+ * virtio_queue_set_guest_notifier - set/unset queue or config guest
+ * notifier
+ *
+ * @vdev: the VirtIO device
+ * @n: queue number, or VIRTIO_CONFIG_IRQ_IDX to set config notifer
+ * @assign: true to set notifier, false to unset
+ * @with_irqfd: irqfd enabled
+ */
+int virtio_queue_set_guest_notifier(VirtIODevice *vdev, int n, bool assign,
+ bool with_irqfd);
static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
{
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 09/23] virtio: drop *_set_guest_notifier_fd_handler() helpers
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (7 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 10/23] vhost-user: keep QIOChannelSocket for backend channel Vladimir Sementsov-Ogievskiy
` (13 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst; +Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin
Now they don't make code more readable. Let's better put the whole
logic into virtio_queue_set_guest_notifier().
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/virtio/virtio.c | 76 +++++++++++-----------------------------------
1 file changed, 17 insertions(+), 59 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index ea43ea620c..692c1979fd 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3829,74 +3829,32 @@ static void virtio_config_guest_notifier_read(EventNotifier *n)
}
}
-static void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq,
- bool assign,
- bool with_irqfd)
-{
- if (assign && !with_irqfd) {
- event_notifier_set_handler(&vq->guest_notifier,
- virtio_queue_guest_notifier_read);
- } else {
- event_notifier_set_handler(&vq->guest_notifier, NULL);
- }
- if (!assign) {
- /* Test and clear notifier before closing it,
- * in case poll callback didn't have time to run. */
- virtio_queue_guest_notifier_read(&vq->guest_notifier);
- }
-}
-
-static void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
- bool assign, bool with_irqfd)
-{
- EventNotifier *n;
- n = &vdev->config_notifier;
- if (assign && !with_irqfd) {
- event_notifier_set_handler(n, virtio_config_guest_notifier_read);
- } else {
- event_notifier_set_handler(n, NULL);
- }
- if (!assign) {
- /* Test and clear notifier before closing it,*/
- /* in case poll callback didn't have time to run. */
- virtio_config_guest_notifier_read(n);
- }
-}
-
-static void virtio_pci_set_guest_notifier_fd_handler(VirtIODevice *vdev,
- VirtQueue *vq,
- int n, bool assign,
- bool with_irqfd)
-{
- if (n == VIRTIO_CONFIG_IRQ_IDX) {
- virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
- } else {
- virtio_queue_set_guest_notifier_fd_handler(vq, assign, with_irqfd);
- }
-}
-
int virtio_queue_set_guest_notifier(VirtIODevice *vdev, int n, bool assign,
bool with_irqfd)
{
- VirtQueue *vq = NULL;
- EventNotifier *notifier = NULL;
-
- if (n == VIRTIO_CONFIG_IRQ_IDX) {
- notifier = virtio_config_get_guest_notifier(vdev);
- } else {
- vq = virtio_get_queue(vdev, n);
- notifier = virtio_queue_get_guest_notifier(vq);
- }
+ bool is_config = n == VIRTIO_CONFIG_IRQ_IDX;
+ VirtQueue *vq = is_config ? NULL : virtio_get_queue(vdev, n);
+ EventNotifier *notifier = is_config ?
+ virtio_config_get_guest_notifier(vdev) :
+ virtio_queue_get_guest_notifier(vq);
+ EventNotifierHandler *read_fn = is_config ?
+ virtio_config_guest_notifier_read :
+ virtio_queue_guest_notifier_read;
if (assign) {
int r = event_notifier_init(notifier, 0);
if (r < 0) {
return r;
}
- virtio_pci_set_guest_notifier_fd_handler(vdev, vq, n, true, with_irqfd);
- } else {
- virtio_pci_set_guest_notifier_fd_handler(vdev, vq, n, false,
- with_irqfd);
+ }
+
+ event_notifier_set_handler(notifier,
+ (assign && !with_irqfd) ? read_fn : NULL);
+
+ if (!assign) {
+ /* Test and clear notifier before closing it,*/
+ /* in case poll callback didn't have time to run. */
+ read_fn(notifier);
event_notifier_cleanup(notifier);
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 10/23] vhost-user: keep QIOChannelSocket for backend channel
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (8 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 09/23] virtio: drop *_set_guest_notifier_fd_handler() helpers Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 11/23] vhost: vhost_virtqueue_start(): fix failure path Vladimir Sementsov-Ogievskiy
` (12 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
Keep QIOChannelSocket pointer instead of more generic
QIOChannel. No real difference for now, but it would
be simpler to migrate socket fd in further commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Acked-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/virtio/vhost-user.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 6b79f50043..aedd5a80ff 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -244,7 +244,7 @@ struct vhost_user {
struct vhost_dev *dev;
/* Shared between vhost devs of the same virtio device */
VhostUserState *user;
- QIOChannel *backend_ioc;
+ QIOChannelSocket *backend_sioc;
GSource *backend_src;
NotifierWithReturn postcopy_notifier;
struct PostCopyFD postcopy_fd;
@@ -1799,8 +1799,8 @@ static void close_backend_channel(struct vhost_user *u)
g_source_destroy(u->backend_src);
g_source_unref(u->backend_src);
u->backend_src = NULL;
- object_unref(OBJECT(u->backend_ioc));
- u->backend_ioc = NULL;
+ object_unref(OBJECT(u->backend_sioc));
+ u->backend_sioc = NULL;
}
static gboolean backend_read(QIOChannel *ioc, GIOCondition condition,
@@ -1912,7 +1912,6 @@ static int vhost_setup_backend_channel(struct vhost_dev *dev)
bool reply_supported =
vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
Error *local_err = NULL;
- QIOChannel *ioc;
if (!vhost_user_has_protocol_feature(
dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ)) {
@@ -1925,15 +1924,15 @@ static int vhost_setup_backend_channel(struct vhost_dev *dev)
return -saved_errno;
}
- ioc = QIO_CHANNEL(qio_channel_socket_new_fd(sv[0], &local_err));
- if (!ioc) {
+ u->backend_sioc = qio_channel_socket_new_fd(sv[0], &local_err);
+ if (!u->backend_sioc) {
error_report_err(local_err);
return -ECONNREFUSED;
}
- u->backend_ioc = ioc;
- u->backend_src = qio_channel_add_watch_source(u->backend_ioc,
- G_IO_IN | G_IO_HUP,
- backend_read, dev, NULL, NULL);
+ u->backend_src = qio_channel_add_watch_source(QIO_CHANNEL(u->backend_sioc),
+ G_IO_IN | G_IO_HUP,
+ backend_read, dev,
+ NULL, NULL);
if (reply_supported) {
msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
@@ -2344,7 +2343,7 @@ static int vhost_user_backend_cleanup(struct vhost_dev *dev)
close(u->postcopy_fd.fd);
u->postcopy_fd.handler = NULL;
}
- if (u->backend_ioc) {
+ if (u->backend_sioc) {
close_backend_channel(u);
}
g_free(u->region_rb);
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 11/23] vhost: vhost_virtqueue_start(): fix failure path
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (9 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 10/23] vhost-user: keep QIOChannelSocket for backend channel Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 23:49 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 12/23] vhost: make vhost_memory_unmap() null-safe Vladimir Sementsov-Ogievskiy
` (11 subsequent siblings)
22 siblings, 1 reply; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst; +Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin
We miss call to unmap in cases when vhost_memory_map() returns
lenght less than requested (still we consider such cases as an
error). Let's fix it in vhost_memory_map().
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
hw/virtio/vhost.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 40440c6d68..1ef9b3ed6c 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -454,11 +454,20 @@ static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size)
}
static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
- hwaddr *plen, bool is_write)
+ hwaddr len, bool is_write)
{
if (!vhost_dev_has_iommu(dev)) {
- return address_space_map(dev->vdev->dma_as, addr, plen, is_write,
- MEMTXATTRS_UNSPECIFIED);
+ hwaddr mapped_len = len;
+ void *res = address_space_map(dev->vdev->dma_as, addr, &mapped_len,
+ is_write, MEMTXATTRS_UNSPECIFIED);
+ if (!res) {
+ return NULL;
+ }
+ if (len != mapped_len) {
+ address_space_unmap(dev->vdev->dma_as, res, mapped_len, 0, 0);
+ return NULL;
+ }
+ return res;
} else {
return (void *)(uintptr_t)addr;
}
@@ -1312,22 +1321,22 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
}
l = vq->desc_size;
- vq->desc = vhost_memory_map(dev, vq->desc_phys, &l, false);
- if (!vq->desc || l != vq->desc_size) {
+ vq->desc = vhost_memory_map(dev, vq->desc_phys, l, false);
+ if (!vq->desc) {
r = -ENOMEM;
goto fail_alloc_desc;
}
l = vq->avail_size;
- vq->avail = vhost_memory_map(dev, vq->avail_phys, &l, false);
- if (!vq->avail || l != vq->avail_size) {
+ vq->avail = vhost_memory_map(dev, vq->avail_phys, l, false);
+ if (!vq->avail) {
r = -ENOMEM;
goto fail_alloc_avail;
}
l = vq->used_size;
- vq->used = vhost_memory_map(dev, vq->used_phys, &l, true);
- if (!vq->used || l != vq->used_size) {
+ vq->used = vhost_memory_map(dev, vq->used_phys, l, true);
+ if (!vq->used) {
r = -ENOMEM;
goto fail_alloc_used;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 12/23] vhost: make vhost_memory_unmap() null-safe
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (10 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 11/23] vhost: vhost_virtqueue_start(): fix failure path Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 13/23] vhost: simplify calls to vhost_memory_unmap() Vladimir Sementsov-Ogievskiy
` (10 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
This helps to simplify failure paths of vhost_virtqueue_start()
a lot. We also need to zero-out pointers on unmap, to not try
to unmap invalid pointers.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/virtio/vhost.c | 41 +++++++++++++++++++++--------------------
1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 1ef9b3ed6c..036c28dead 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -473,14 +473,20 @@ static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
}
}
-static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer,
+static void vhost_memory_unmap(struct vhost_dev *dev, void **buffer,
hwaddr len, int is_write,
hwaddr access_len)
{
+ if (!*buffer) {
+ return;
+ }
+
if (!vhost_dev_has_iommu(dev)) {
- address_space_unmap(dev->vdev->dma_as, buffer, len, is_write,
+ address_space_unmap(dev->vdev->dma_as, *buffer, len, is_write,
access_len);
}
+
+ *buffer = NULL;
}
static int vhost_verify_ring_part_mapping(void *ring_hva,
@@ -1324,33 +1330,33 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
vq->desc = vhost_memory_map(dev, vq->desc_phys, l, false);
if (!vq->desc) {
r = -ENOMEM;
- goto fail_alloc_desc;
+ goto fail;
}
l = vq->avail_size;
vq->avail = vhost_memory_map(dev, vq->avail_phys, l, false);
if (!vq->avail) {
r = -ENOMEM;
- goto fail_alloc_avail;
+ goto fail;
}
l = vq->used_size;
vq->used = vhost_memory_map(dev, vq->used_phys, l, true);
if (!vq->used) {
r = -ENOMEM;
- goto fail_alloc_used;
+ goto fail;
}
r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
if (r < 0) {
- goto fail_alloc;
+ goto fail;
}
file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
r = dev->vhost_ops->vhost_set_vring_kick(dev, &file);
if (r) {
VHOST_OPS_DEBUG(r, "vhost_set_vring_kick failed");
- goto fail_kick;
+ goto fail;
}
/* Clear and discard previous events if any. */
@@ -1370,24 +1376,19 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
file.fd = -1;
r = dev->vhost_ops->vhost_set_vring_call(dev, &file);
if (r) {
- goto fail_vector;
+ goto fail;
}
}
return 0;
-fail_vector:
-fail_kick:
-fail_alloc:
- vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx),
+fail:
+ vhost_memory_unmap(dev, &vq->used, virtio_queue_get_used_size(vdev, idx),
0, 0);
-fail_alloc_used:
- vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx),
+ vhost_memory_unmap(dev, &vq->avail, virtio_queue_get_avail_size(vdev, idx),
0, 0);
-fail_alloc_avail:
- vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx),
+ vhost_memory_unmap(dev, &vq->desc, virtio_queue_get_desc_size(vdev, idx),
0, 0);
-fail_alloc_desc:
return r;
}
@@ -1434,11 +1435,11 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
vhost_vq_index);
}
- vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx),
+ vhost_memory_unmap(dev, &vq->used, virtio_queue_get_used_size(vdev, idx),
1, virtio_queue_get_used_size(vdev, idx));
- vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx),
+ vhost_memory_unmap(dev, &vq->avail, virtio_queue_get_avail_size(vdev, idx),
0, virtio_queue_get_avail_size(vdev, idx));
- vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx),
+ vhost_memory_unmap(dev, &vq->desc, virtio_queue_get_desc_size(vdev, idx),
0, virtio_queue_get_desc_size(vdev, idx));
return r;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 13/23] vhost: simplify calls to vhost_memory_unmap()
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (11 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 12/23] vhost: make vhost_memory_unmap() null-safe Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 14/23] vhost: move vrings mapping to the top of vhost_virtqueue_start() Vladimir Sementsov-Ogievskiy
` (9 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
No reason to calculate memory size again, as we have corresponding
variable for each vring.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/virtio/vhost.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 036c28dead..84937c8a67 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1383,12 +1383,9 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
return 0;
fail:
- vhost_memory_unmap(dev, &vq->used, virtio_queue_get_used_size(vdev, idx),
- 0, 0);
- vhost_memory_unmap(dev, &vq->avail, virtio_queue_get_avail_size(vdev, idx),
- 0, 0);
- vhost_memory_unmap(dev, &vq->desc, virtio_queue_get_desc_size(vdev, idx),
- 0, 0);
+ vhost_memory_unmap(dev, &vq->used, vq->used_size, 0, 0);
+ vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0, 0);
+ vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0, 0);
return r;
}
@@ -1435,12 +1432,9 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
vhost_vq_index);
}
- vhost_memory_unmap(dev, &vq->used, virtio_queue_get_used_size(vdev, idx),
- 1, virtio_queue_get_used_size(vdev, idx));
- vhost_memory_unmap(dev, &vq->avail, virtio_queue_get_avail_size(vdev, idx),
- 0, virtio_queue_get_avail_size(vdev, idx));
- vhost_memory_unmap(dev, &vq->desc, virtio_queue_get_desc_size(vdev, idx),
- 0, virtio_queue_get_desc_size(vdev, idx));
+ vhost_memory_unmap(dev, &vq->used, vq->used_size, 1, vq->used_size);
+ vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0, vq->avail_size);
+ vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0, vq->desc_size);
return r;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 14/23] vhost: move vrings mapping to the top of vhost_virtqueue_start()
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (12 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 13/23] vhost: simplify calls to vhost_memory_unmap() Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 15/23] vhost: vhost_virtqueue_start(): drop extra local variables Vladimir Sementsov-Ogievskiy
` (8 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
This simplifies further refactoring and final introduction
of vhost backend live migration.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/virtio/vhost.c | 46 +++++++++++++++++++++++-----------------------
1 file changed, 23 insertions(+), 23 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 84937c8a67..06b0b34cd3 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1303,29 +1303,6 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
return 0;
}
- vq->num = state.num = virtio_queue_get_num(vdev, idx);
- r = dev->vhost_ops->vhost_set_vring_num(dev, &state);
- if (r) {
- VHOST_OPS_DEBUG(r, "vhost_set_vring_num failed");
- return r;
- }
-
- state.num = virtio_queue_get_last_avail_idx(vdev, idx);
- r = dev->vhost_ops->vhost_set_vring_base(dev, &state);
- if (r) {
- VHOST_OPS_DEBUG(r, "vhost_set_vring_base failed");
- return r;
- }
-
- if (vhost_needs_vring_endian(vdev)) {
- r = vhost_virtqueue_set_vring_endian_legacy(dev,
- virtio_is_big_endian(vdev),
- vhost_vq_index);
- if (r) {
- return r;
- }
- }
-
l = vq->desc_size;
vq->desc = vhost_memory_map(dev, vq->desc_phys, l, false);
if (!vq->desc) {
@@ -1347,6 +1324,29 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
goto fail;
}
+ vq->num = state.num = virtio_queue_get_num(vdev, idx);
+ r = dev->vhost_ops->vhost_set_vring_num(dev, &state);
+ if (r) {
+ VHOST_OPS_DEBUG(r, "vhost_set_vring_num failed");
+ goto fail;
+ }
+
+ state.num = virtio_queue_get_last_avail_idx(vdev, idx);
+ r = dev->vhost_ops->vhost_set_vring_base(dev, &state);
+ if (r) {
+ VHOST_OPS_DEBUG(r, "vhost_set_vring_base failed");
+ goto fail;
+ }
+
+ if (vhost_needs_vring_endian(vdev)) {
+ r = vhost_virtqueue_set_vring_endian_legacy(dev,
+ virtio_is_big_endian(vdev),
+ vhost_vq_index);
+ if (r) {
+ goto fail;
+ }
+ }
+
r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
if (r < 0) {
goto fail;
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 15/23] vhost: vhost_virtqueue_start(): drop extra local variables
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (13 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 14/23] vhost: move vrings mapping to the top of vhost_virtqueue_start() Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 23:49 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 16/23] vhost: final refactoring of vhost vrings map/unmap Vladimir Sementsov-Ogievskiy
` (7 subsequent siblings)
22 siblings, 1 reply; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst; +Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin
One letter named variables doesn't really help to read the code,
and they simply duplicate structure fields.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
hw/virtio/vhost.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 06b0b34cd3..653cb706cc 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1277,7 +1277,6 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusState *vbus = VIRTIO_BUS(qbus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
- hwaddr l;
int r;
int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx);
struct vhost_vring_file file = {
@@ -1302,23 +1301,17 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
/* Queue might not be ready for start */
return 0;
}
-
- l = vq->desc_size;
- vq->desc = vhost_memory_map(dev, vq->desc_phys, l, false);
+ vq->desc = vhost_memory_map(dev, vq->desc_phys, vq->desc_size, false);
if (!vq->desc) {
r = -ENOMEM;
goto fail;
}
-
- l = vq->avail_size;
- vq->avail = vhost_memory_map(dev, vq->avail_phys, l, false);
+ vq->avail = vhost_memory_map(dev, vq->avail_phys, vq->avail_size, false);
if (!vq->avail) {
r = -ENOMEM;
goto fail;
}
-
- l = vq->used_size;
- vq->used = vhost_memory_map(dev, vq->used_phys, l, true);
+ vq->used = vhost_memory_map(dev, vq->used_phys, vq->used_size, true);
if (!vq->used) {
r = -ENOMEM;
goto fail;
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 16/23] vhost: final refactoring of vhost vrings map/unmap
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (14 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 15/23] vhost: vhost_virtqueue_start(): drop extra local variables Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 23:50 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 17/23] vhost: simplify vhost_dev_init() error-path Vladimir Sementsov-Ogievskiy
` (6 subsequent siblings)
22 siblings, 1 reply; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst; +Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin
Introduce helper functions vhost_vrings_map() and
vhost_vrings_unmap() and use them.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
hw/virtio/vhost.c | 89 +++++++++++++++++++++++++++++------------------
1 file changed, 55 insertions(+), 34 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 653cb706cc..7efdc4643d 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -489,6 +489,56 @@ static void vhost_memory_unmap(struct vhost_dev *dev, void **buffer,
*buffer = NULL;
}
+static void vhost_vrings_unmap(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq, bool touched)
+{
+ vhost_memory_unmap(dev, &vq->used, vq->used_size, touched,
+ touched ? vq->used_size : 0);
+ vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0,
+ touched ? vq->avail_size : 0);
+ vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0,
+ touched ? vq->desc_size : 0);
+}
+
+static int vhost_vrings_map(struct vhost_dev *dev,
+ struct VirtIODevice *vdev,
+ struct vhost_virtqueue *vq,
+ unsigned idx)
+{
+ vq->desc_size = virtio_queue_get_desc_size(vdev, idx);
+ vq->desc_phys = virtio_queue_get_desc_addr(vdev, idx);
+ vq->desc = NULL;
+ vq->avail_size = virtio_queue_get_avail_size(vdev, idx);
+ vq->avail_phys = virtio_queue_get_avail_addr(vdev, idx);
+ vq->avail = NULL;
+ vq->used_size = virtio_queue_get_used_size(vdev, idx);
+ vq->used_phys = virtio_queue_get_used_addr(vdev, idx);
+ vq->used = NULL;
+
+ if (vq->desc_phys == 0) {
+ /* Queue might not be ready for start */
+ return 0;
+ }
+ vq->desc = vhost_memory_map(dev, vq->desc_phys, vq->desc_size, false);
+ if (!vq->desc) {
+ goto fail;
+ }
+ vq->avail = vhost_memory_map(dev, vq->avail_phys, vq->avail_size, false);
+ if (!vq->avail) {
+ goto fail;
+ }
+ vq->used = vhost_memory_map(dev, vq->used_phys, vq->used_size, true);
+ if (!vq->used) {
+ goto fail;
+ }
+
+ return 1;
+
+fail:
+ vhost_vrings_unmap(dev, vq, false);
+ return -ENOMEM;
+}
+
static int vhost_verify_ring_part_mapping(void *ring_hva,
uint64_t ring_gpa,
uint64_t ring_size,
@@ -1287,34 +1337,9 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
};
struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
- vq->desc_size = virtio_queue_get_desc_size(vdev, idx);
- vq->desc_phys = virtio_queue_get_desc_addr(vdev, idx);
- vq->desc = NULL;
- vq->avail_size = virtio_queue_get_avail_size(vdev, idx);
- vq->avail_phys = virtio_queue_get_avail_addr(vdev, idx);
- vq->avail = NULL;
- vq->used_size = virtio_queue_get_used_size(vdev, idx);
- vq->used_phys = virtio_queue_get_used_addr(vdev, idx);
- vq->used = NULL;
-
- if (vq->desc_phys == 0) {
- /* Queue might not be ready for start */
- return 0;
- }
- vq->desc = vhost_memory_map(dev, vq->desc_phys, vq->desc_size, false);
- if (!vq->desc) {
- r = -ENOMEM;
- goto fail;
- }
- vq->avail = vhost_memory_map(dev, vq->avail_phys, vq->avail_size, false);
- if (!vq->avail) {
- r = -ENOMEM;
- goto fail;
- }
- vq->used = vhost_memory_map(dev, vq->used_phys, vq->used_size, true);
- if (!vq->used) {
- r = -ENOMEM;
- goto fail;
+ r = vhost_vrings_map(dev, vdev, vq, idx);
+ if (r <= 0) {
+ return r;
}
vq->num = state.num = virtio_queue_get_num(vdev, idx);
@@ -1376,9 +1401,7 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
return 0;
fail:
- vhost_memory_unmap(dev, &vq->used, vq->used_size, 0, 0);
- vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0, 0);
- vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0, 0);
+ vhost_vrings_unmap(dev, vq, false);
return r;
}
@@ -1425,9 +1448,7 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
vhost_vq_index);
}
- vhost_memory_unmap(dev, &vq->used, vq->used_size, 1, vq->used_size);
- vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0, vq->avail_size);
- vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0, vq->desc_size);
+ vhost_vrings_unmap(dev, vq, true);
return r;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 17/23] vhost: simplify vhost_dev_init() error-path
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (15 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 16/23] vhost: final refactoring of vhost vrings map/unmap Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 18/23] vhost: move busyloop timeout initialization to vhost_virtqueue_init() Vladimir Sementsov-Ogievskiy
` (5 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
No reason to rollback setting up busyloop timeout on failure.
We don't do such rollback for other things we setup in backend.
Also, look at vhost_net_init() in hw/net/vhost_net.c: we may fail
after successfully called vhost_dev_init(), and in this case we'll
just call vhost_dev_cleanup(), which doesn't rollback busyloop
timeout.
So, let's keep it simple.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Acked-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/virtio/vhost.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7efdc4643d..412bbd9063 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1625,7 +1625,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
busyloop_timeout);
if (r < 0) {
error_setg_errno(errp, -r, "Failed to set busyloop timeout");
- goto fail_busyloop;
+ goto fail;
}
}
}
@@ -1665,7 +1665,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
if (hdev->migration_blocker != NULL) {
r = migrate_add_blocker_normal(&hdev->migration_blocker, errp);
if (r < 0) {
- goto fail_busyloop;
+ goto fail;
}
}
@@ -1697,17 +1697,11 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
" than current number of used (%d) and reserved (%d)"
" memory slots for memory devices.", limit, used, reserved);
r = -EINVAL;
- goto fail_busyloop;
+ goto fail;
}
return 0;
-fail_busyloop:
- if (busyloop_timeout) {
- while (--i >= 0) {
- vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
- }
- }
fail:
hdev->nvqs = n_initialized_vqs;
vhost_dev_cleanup(hdev);
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 18/23] vhost: move busyloop timeout initialization to vhost_virtqueue_init()
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (16 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 17/23] vhost: simplify vhost_dev_init() error-path Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 19/23] vhost: vhost_dev_init(): simplify features initialization Vladimir Sementsov-Ogievskiy
` (4 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
Let's all per-virtqueue initializations be in one place.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/virtio/vhost.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 412bbd9063..b9f26a4ee8 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1497,7 +1497,8 @@ static void vhost_virtqueue_error_notifier(EventNotifier *n)
}
static int vhost_virtqueue_init(struct vhost_dev *dev,
- struct vhost_virtqueue *vq, int n)
+ struct vhost_virtqueue *vq, int n,
+ bool busyloop_timeout)
{
int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n);
struct vhost_vring_file file = {
@@ -1534,6 +1535,14 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
vhost_virtqueue_error_notifier);
}
+ if (busyloop_timeout) {
+ r = vhost_virtqueue_set_busyloop_timeout(dev, n, busyloop_timeout);
+ if (r < 0) {
+ VHOST_OPS_DEBUG(r, "Failed to set busyloop timeout");
+ goto fail_err;
+ }
+ }
+
return 0;
fail_err:
@@ -1612,24 +1621,14 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
}
for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) {
- r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i);
+ r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i,
+ busyloop_timeout);
if (r < 0) {
error_setg_errno(errp, -r, "Failed to initialize virtqueue %d", i);
goto fail;
}
}
- if (busyloop_timeout) {
- for (i = 0; i < hdev->nvqs; ++i) {
- r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i,
- busyloop_timeout);
- if (r < 0) {
- error_setg_errno(errp, -r, "Failed to set busyloop timeout");
- goto fail;
- }
- }
- }
-
virtio_features_copy(hdev->_features_ex, features);
hdev->memory_listener = (MemoryListener) {
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 19/23] vhost: vhost_dev_init(): simplify features initialization
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (17 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 18/23] vhost: move busyloop timeout initialization to vhost_virtqueue_init() Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 20/23] hw/virtio/virtio-bus: refactor virtio_bus_set_host_notifier() Vladimir Sementsov-Ogievskiy
` (3 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
Drop extra variable and extra function parameter passing, initialize
dev._features directly.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/virtio/vhost.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index b9f26a4ee8..ad49b9cc2f 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1561,18 +1561,17 @@ static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq)
}
}
-static int vhost_dev_get_features(struct vhost_dev *hdev,
- uint64_t *features)
+static int vhost_dev_init_features(struct vhost_dev *hdev)
{
uint64_t features64;
int r;
if (hdev->vhost_ops->vhost_get_features_ex) {
- return hdev->vhost_ops->vhost_get_features_ex(hdev, features);
+ return hdev->vhost_ops->vhost_get_features_ex(hdev, hdev->_features_ex);
}
r = hdev->vhost_ops->vhost_get_features(hdev, &features64);
- virtio_features_from_u64(features, features64);
+ virtio_features_from_u64(hdev->_features_ex, features64);
return r;
}
@@ -1580,7 +1579,6 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
VhostBackendType backend_type, uint32_t busyloop_timeout,
Error **errp)
{
- uint64_t features[VIRTIO_FEATURES_NU64S];
unsigned int used, reserved, limit;
int i, r, n_initialized_vqs = 0;
@@ -1601,9 +1599,9 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
goto fail;
}
- r = vhost_dev_get_features(hdev, features);
+ r = vhost_dev_init_features(hdev);
if (r < 0) {
- error_setg_errno(errp, -r, "vhost_get_features failed");
+ error_setg_errno(errp, -r, "vhost_init_features failed");
goto fail;
}
@@ -1629,8 +1627,6 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
}
}
- virtio_features_copy(hdev->_features_ex, features);
-
hdev->memory_listener = (MemoryListener) {
.name = "vhost",
.begin = vhost_begin,
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 20/23] hw/virtio/virtio-bus: refactor virtio_bus_set_host_notifier()
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (18 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 19/23] vhost: vhost_dev_init(): simplify features initialization Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 21/23] vhost-user: make trace events more readable Vladimir Sementsov-Ogievskiy
` (2 subsequent siblings)
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Philippe Mathieu-Daudé, Raphael Norwitz
The logic kept as is. Refactor to simplify further changes.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
---
hw/virtio/virtio-bus.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index cef944e015..9b545acda3 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -298,20 +298,18 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
__func__, strerror(-r), r);
return r;
}
- r = k->ioeventfd_assign(proxy, notifier, n, true);
- if (r < 0) {
- error_report("%s: unable to assign ioeventfd: %d", __func__, r);
- virtio_bus_cleanup_host_notifier(bus, n);
- }
- } else {
- k->ioeventfd_assign(proxy, notifier, n, false);
}
- if (r == 0) {
- virtio_queue_set_host_notifier_enabled(vq, assign);
+ r = k->ioeventfd_assign(proxy, notifier, n, assign);
+ if (r < 0 && assign) {
+ error_report("%s: unable to assign ioeventfd: %d", __func__, r);
+ virtio_bus_cleanup_host_notifier(bus, n);
+ return r;
}
- return r;
+ virtio_queue_set_host_notifier_enabled(vq, assign);
+
+ return 0;
}
void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n)
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 21/23] vhost-user: make trace events more readable
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (19 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 20/23] hw/virtio/virtio-bus: refactor virtio_bus_set_host_notifier() Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 23:50 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 22/23] vhost-user-blk: add some useful trace-points Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 23/23] vhost: " Vladimir Sementsov-Ogievskiy
22 siblings, 1 reply; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst; +Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
hw/virtio/trace-events | 4 +--
hw/virtio/vhost-user.c | 63 ++++++++++++++++++++++++++++++++++++++++--
2 files changed, 63 insertions(+), 4 deletions(-)
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 658cc365e7..aa1ffa5e94 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -25,8 +25,8 @@ vhost_user_set_mem_table_withfd(int index, const char *name, uint64_t memory_siz
vhost_user_postcopy_waker(const char *rb, uint64_t rb_offset) "%s + 0x%"PRIx64
vhost_user_postcopy_waker_found(uint64_t client_addr) "0x%"PRIx64
vhost_user_postcopy_waker_nomatch(const char *rb, uint64_t rb_offset) "%s + 0x%"PRIx64
-vhost_user_read(uint32_t req, uint32_t flags) "req:%d flags:0x%"PRIx32""
-vhost_user_write(uint32_t req, uint32_t flags) "req:%d flags:0x%"PRIx32""
+vhost_user_read(uint32_t req, const char *req_name, uint32_t flags) "req:%d (%s) flags:0x%"PRIx32""
+vhost_user_write(uint32_t req, const char *req_name, uint32_t flags) "req:%d (%s) flags:0x%"PRIx32""
vhost_user_create_notifier(int idx, void *n) "idx:%d n:%p"
# vhost-vdpa.c
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index aedd5a80ff..824943f1eb 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -119,6 +119,63 @@ typedef enum VhostUserBackendRequest {
VHOST_USER_BACKEND_MAX
} VhostUserBackendRequest;
+#define VHOST_USER_CASE(name) \
+ case VHOST_USER_##name: \
+ return #name;
+
+static const char *vhost_req_name(VhostUserRequest req)
+{
+ switch (req) {
+ VHOST_USER_CASE(NONE)
+ VHOST_USER_CASE(GET_FEATURES)
+ VHOST_USER_CASE(SET_FEATURES)
+ VHOST_USER_CASE(SET_OWNER)
+ VHOST_USER_CASE(RESET_OWNER)
+ VHOST_USER_CASE(SET_MEM_TABLE)
+ VHOST_USER_CASE(SET_LOG_BASE)
+ VHOST_USER_CASE(SET_LOG_FD)
+ VHOST_USER_CASE(SET_VRING_NUM)
+ VHOST_USER_CASE(SET_VRING_ADDR)
+ VHOST_USER_CASE(SET_VRING_BASE)
+ VHOST_USER_CASE(GET_VRING_BASE)
+ VHOST_USER_CASE(SET_VRING_KICK)
+ VHOST_USER_CASE(SET_VRING_CALL)
+ VHOST_USER_CASE(SET_VRING_ERR)
+ VHOST_USER_CASE(GET_PROTOCOL_FEATURES)
+ VHOST_USER_CASE(SET_PROTOCOL_FEATURES)
+ VHOST_USER_CASE(GET_QUEUE_NUM)
+ VHOST_USER_CASE(SET_VRING_ENABLE)
+ VHOST_USER_CASE(SEND_RARP)
+ VHOST_USER_CASE(NET_SET_MTU)
+ VHOST_USER_CASE(SET_BACKEND_REQ_FD)
+ VHOST_USER_CASE(IOTLB_MSG)
+ VHOST_USER_CASE(SET_VRING_ENDIAN)
+ VHOST_USER_CASE(GET_CONFIG)
+ VHOST_USER_CASE(SET_CONFIG)
+ VHOST_USER_CASE(CREATE_CRYPTO_SESSION)
+ VHOST_USER_CASE(CLOSE_CRYPTO_SESSION)
+ VHOST_USER_CASE(POSTCOPY_ADVISE)
+ VHOST_USER_CASE(POSTCOPY_LISTEN)
+ VHOST_USER_CASE(POSTCOPY_END)
+ VHOST_USER_CASE(GET_INFLIGHT_FD)
+ VHOST_USER_CASE(SET_INFLIGHT_FD)
+ VHOST_USER_CASE(GPU_SET_SOCKET)
+ VHOST_USER_CASE(RESET_DEVICE)
+ VHOST_USER_CASE(GET_MAX_MEM_SLOTS)
+ VHOST_USER_CASE(ADD_MEM_REG)
+ VHOST_USER_CASE(REM_MEM_REG)
+ VHOST_USER_CASE(SET_STATUS)
+ VHOST_USER_CASE(GET_STATUS)
+ VHOST_USER_CASE(GET_SHARED_OBJECT)
+ VHOST_USER_CASE(SET_DEVICE_STATE_FD)
+ VHOST_USER_CASE(CHECK_DEVICE_STATE)
+ default:
+ return "<unknown>";
+ }
+}
+
+#undef VHOST_USER_CASE
+
typedef struct VhostUserMemoryRegion {
uint64_t guest_phys_addr;
uint64_t memory_size;
@@ -311,7 +368,8 @@ static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
return -EPROTO;
}
- trace_vhost_user_read(msg->hdr.request, msg->hdr.flags);
+ trace_vhost_user_read(msg->hdr.request,
+ vhost_req_name(msg->hdr.request), msg->hdr.flags);
return 0;
}
@@ -431,7 +489,8 @@ static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
return ret < 0 ? -saved_errno : -EIO;
}
- trace_vhost_user_write(msg->hdr.request, msg->hdr.flags);
+ trace_vhost_user_write(msg->hdr.request, vhost_req_name(msg->hdr.request),
+ msg->hdr.flags);
return 0;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 22/23] vhost-user-blk: add some useful trace-points
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (20 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 21/23] vhost-user: make trace events more readable Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 23/23] vhost: " Vladimir Sementsov-Ogievskiy
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz, Kevin Wolf, Hanna Reitz,
open list:Block layer core
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/block/trace-events | 10 ++++++++++
hw/block/vhost-user-blk.c | 19 +++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/hw/block/trace-events b/hw/block/trace-events
index cc9a9f2460..dbaa5ca6cb 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -58,6 +58,16 @@ virtio_blk_handle_zone_mgmt(void *vdev, void *req, uint8_t op, int64_t sector, i
virtio_blk_handle_zone_reset_all(void *vdev, void *req, int64_t sector, int64_t len) "vdev %p req %p sector 0x%" PRIx64 " cap 0x%" PRIx64 ""
virtio_blk_handle_zone_append(void *vdev, void *req, int64_t sector) "vdev %p req %p, append sector 0x%" PRIx64 ""
+# vhost-user-blk.c
+vhost_user_blk_start_in(void *vdev) "vdev %p"
+vhost_user_blk_start_out(void *vdev) "vdev %p"
+vhost_user_blk_stop_in(void *vdev) "vdev %p"
+vhost_user_blk_stop_out(void *vdev) "vdev %p"
+vhost_user_blk_connect_in(void *vdev) "vdev %p"
+vhost_user_blk_connect_out(void *vdev) "vdev %p"
+vhost_user_blk_device_realize_in(void *vdev) "vdev %p"
+vhost_user_blk_device_realize_out(void *vdev) "vdev %p"
+
# hd-geometry.c
hd_geometry_lchs_guess(void *blk, int cyls, int heads, int secs) "blk %p LCHS %d %d %d"
hd_geometry_guess(void *blk, uint32_t cyls, uint32_t heads, uint32_t secs, int trans) "blk %p CHS %u %u %u trans %d"
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index c8f7156ca6..cca17b30d9 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -31,6 +31,7 @@
#include "hw/virtio/virtio-access.h"
#include "system/system.h"
#include "system/runstate.h"
+#include "trace.h"
static const int user_feature_bits[] = {
VIRTIO_BLK_F_SIZE_MAX,
@@ -137,6 +138,8 @@ static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp)
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int i, ret;
+ trace_vhost_user_blk_start_in(vdev);
+
if (!k->set_guest_notifiers) {
error_setg(errp, "binding does not support guest notifiers");
return -ENOSYS;
@@ -192,6 +195,8 @@ static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp)
}
s->started_vu = true;
+ trace_vhost_user_blk_start_out(vdev);
+
return ret;
err_guest_notifiers:
@@ -212,6 +217,8 @@ static int vhost_user_blk_stop(VirtIODevice *vdev)
int ret;
bool force_stop = false;
+ trace_vhost_user_blk_stop_in(vdev);
+
if (!s->started_vu) {
return 0;
}
@@ -233,6 +240,9 @@ static int vhost_user_blk_stop(VirtIODevice *vdev)
}
vhost_dev_disable_notifiers(&s->dev, vdev);
+
+ trace_vhost_user_blk_stop_out(vdev);
+
return ret;
}
@@ -340,6 +350,8 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
VHostUserBlk *s = VHOST_USER_BLK(vdev);
int ret = 0;
+ trace_vhost_user_blk_connect_in(vdev);
+
if (s->connected) {
return 0;
}
@@ -365,6 +377,8 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
ret = vhost_user_blk_start(vdev, errp);
}
+ trace_vhost_user_blk_connect_out(vdev);
+
return ret;
}
@@ -455,6 +469,8 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
int retries;
int i, ret;
+ trace_vhost_user_blk_device_realize_in(vdev);
+
if (!s->chardev.chr) {
error_setg(errp, "chardev is mandatory");
return;
@@ -514,6 +530,9 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL,
vhost_user_blk_event, NULL, (void *)dev,
NULL, true);
+
+ trace_vhost_user_blk_device_realize_out(vdev);
+
return;
virtio_err:
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* [PATCH v4 23/23] vhost: add some useful trace-points
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
` (21 preceding siblings ...)
2026-01-19 18:52 ` [PATCH v4 22/23] vhost-user-blk: add some useful trace-points Vladimir Sementsov-Ogievskiy
@ 2026-01-19 18:52 ` Vladimir Sementsov-Ogievskiy
22 siblings, 0 replies; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-19 18:52 UTC (permalink / raw)
To: mst
Cc: sgarzare, raphael, qemu-devel, vsementsov, yc-core, d-tatianin,
Raphael Norwitz
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
---
hw/virtio/trace-events | 12 ++++++++++--
hw/virtio/vhost.c | 20 ++++++++++++++++++--
2 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index aa1ffa5e94..2a57edc21e 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -9,8 +9,16 @@ 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, bool vrings) "%p:%s vrings:%d"
-vhost_dev_stop(void *dev, const char *name, bool vrings) "%p:%s vrings:%d"
+vhost_dev_start_in(void *dev, const char *name, bool vrings) "%p:%s vrings:%d"
+vhost_dev_start_out(void *dev, const char *name) "%p:%s"
+vhost_dev_stop_in(void *dev, const char *name, bool vrings) "%p:%s vrings:%d"
+vhost_dev_stop_out(void *dev, const char *name) "%p:%s"
+vhost_virtqueue_start_in(void *dev, const char *name, int idx) "%p:%s %d"
+vhost_virtqueue_start_out(void *dev, const char *name, int idx) "%p:%s %d"
+vhost_virtqueue_stop_in(void *dev, const char *name, int idx) "%p:%s %d"
+vhost_virtqueue_stop_out(void *dev, const char *name, int idx) "%p:%s %d"
+vhost_dev_init_in(void *dev) "%p"
+vhost_dev_init_out(void *dev) "%p"
# vhost-user.c
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index ad49b9cc2f..d241c6110f 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1337,6 +1337,8 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
};
struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
+ trace_vhost_virtqueue_start_in(dev, vdev->name, idx);
+
r = vhost_vrings_map(dev, vdev, vq, idx);
if (r <= 0) {
return r;
@@ -1398,6 +1400,8 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
}
}
+ trace_vhost_virtqueue_start_out(dev, vdev->name, idx);
+
return 0;
fail:
@@ -1416,6 +1420,8 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
};
int r = 0;
+ trace_vhost_virtqueue_stop_in(dev, vdev->name, idx);
+
if (virtio_queue_get_desc_addr(vdev, idx) == 0) {
/* Don't stop the virtqueue which might have not been started */
return 0;
@@ -1449,6 +1455,8 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
}
vhost_vrings_unmap(dev, vq, true);
+
+ trace_vhost_virtqueue_stop_out(dev, vdev->name, idx);
return r;
}
@@ -1582,6 +1590,8 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
unsigned int used, reserved, limit;
int i, r, n_initialized_vqs = 0;
+ trace_vhost_dev_init_in(hdev);
+
hdev->vdev = NULL;
hdev->migration_blocker = NULL;
@@ -1695,6 +1705,8 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
goto fail;
}
+ trace_vhost_dev_init_out(hdev);
+
return 0;
fail:
@@ -2043,7 +2055,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings)
/* should only be called after backend is connected */
assert(hdev->vhost_ops);
- trace_vhost_dev_start(hdev, vdev->name, vrings);
+ trace_vhost_dev_start_in(hdev, vdev->name, vrings);
vdev->vhost_started = true;
hdev->started = true;
@@ -2128,6 +2140,8 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings)
}
}
vhost_start_config_intr(hdev);
+
+ trace_vhost_dev_start_out(hdev, vdev->name);
return 0;
fail_iotlb:
if (vhost_dev_has_iommu(hdev) &&
@@ -2177,7 +2191,7 @@ static int do_vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev,
event_notifier_cleanup(
&hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier);
- trace_vhost_dev_stop(hdev, vdev->name, vrings);
+ trace_vhost_dev_stop_in(hdev, vdev->name, vrings);
if (hdev->vhost_ops->vhost_dev_start) {
hdev->vhost_ops->vhost_dev_start(hdev, false);
@@ -2207,6 +2221,8 @@ static int do_vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev,
hdev->started = false;
vdev->vhost_started = false;
hdev->vdev = NULL;
+
+ trace_vhost_dev_stop_out(hdev, vdev->name);
return rc;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 37+ messages in thread
* Re: [PATCH v4 11/23] vhost: vhost_virtqueue_start(): fix failure path
2026-01-19 18:52 ` [PATCH v4 11/23] vhost: vhost_virtqueue_start(): fix failure path Vladimir Sementsov-Ogievskiy
@ 2026-01-19 23:49 ` Raphael Norwitz
0 siblings, 0 replies; 37+ messages in thread
From: Raphael Norwitz @ 2026-01-19 23:49 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
On Mon, Jan 19, 2026 at 1:55 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> We miss call to unmap in cases when vhost_memory_map() returns
> lenght less than requested (still we consider such cases as an
> error). Let's fix it in vhost_memory_map().
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/virtio/vhost.c | 27 ++++++++++++++++++---------
> 1 file changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 40440c6d68..1ef9b3ed6c 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -454,11 +454,20 @@ static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size)
> }
>
> static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
> - hwaddr *plen, bool is_write)
> + hwaddr len, bool is_write)
> {
> if (!vhost_dev_has_iommu(dev)) {
> - return address_space_map(dev->vdev->dma_as, addr, plen, is_write,
> - MEMTXATTRS_UNSPECIFIED);
> + hwaddr mapped_len = len;
> + void *res = address_space_map(dev->vdev->dma_as, addr, &mapped_len,
> + is_write, MEMTXATTRS_UNSPECIFIED);
> + if (!res) {
> + return NULL;
> + }
> + if (len != mapped_len) {
> + address_space_unmap(dev->vdev->dma_as, res, mapped_len, 0, 0);
> + return NULL;
> + }
> + return res;
> } else {
> return (void *)(uintptr_t)addr;
> }
> @@ -1312,22 +1321,22 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
> }
>
> l = vq->desc_size;
> - vq->desc = vhost_memory_map(dev, vq->desc_phys, &l, false);
> - if (!vq->desc || l != vq->desc_size) {
> + vq->desc = vhost_memory_map(dev, vq->desc_phys, l, false);
> + if (!vq->desc) {
> r = -ENOMEM;
> goto fail_alloc_desc;
> }
>
> l = vq->avail_size;
> - vq->avail = vhost_memory_map(dev, vq->avail_phys, &l, false);
> - if (!vq->avail || l != vq->avail_size) {
> + vq->avail = vhost_memory_map(dev, vq->avail_phys, l, false);
> + if (!vq->avail) {
> r = -ENOMEM;
> goto fail_alloc_avail;
> }
>
> l = vq->used_size;
> - vq->used = vhost_memory_map(dev, vq->used_phys, &l, true);
> - if (!vq->used || l != vq->used_size) {
> + vq->used = vhost_memory_map(dev, vq->used_phys, l, true);
> + if (!vq->used) {
> r = -ENOMEM;
> goto fail_alloc_used;
> }
> --
> 2.52.0
>
>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 15/23] vhost: vhost_virtqueue_start(): drop extra local variables
2026-01-19 18:52 ` [PATCH v4 15/23] vhost: vhost_virtqueue_start(): drop extra local variables Vladimir Sementsov-Ogievskiy
@ 2026-01-19 23:49 ` Raphael Norwitz
0 siblings, 0 replies; 37+ messages in thread
From: Raphael Norwitz @ 2026-01-19 23:49 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
On Mon, Jan 19, 2026 at 1:55 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> One letter named variables doesn't really help to read the code,
> and they simply duplicate structure fields.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/virtio/vhost.c | 13 +++----------
> 1 file changed, 3 insertions(+), 10 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 06b0b34cd3..653cb706cc 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1277,7 +1277,6 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> VirtioBusState *vbus = VIRTIO_BUS(qbus);
> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> - hwaddr l;
> int r;
> int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx);
> struct vhost_vring_file file = {
> @@ -1302,23 +1301,17 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
> /* Queue might not be ready for start */
> return 0;
> }
> -
> - l = vq->desc_size;
> - vq->desc = vhost_memory_map(dev, vq->desc_phys, l, false);
> + vq->desc = vhost_memory_map(dev, vq->desc_phys, vq->desc_size, false);
> if (!vq->desc) {
> r = -ENOMEM;
> goto fail;
> }
> -
> - l = vq->avail_size;
> - vq->avail = vhost_memory_map(dev, vq->avail_phys, l, false);
> + vq->avail = vhost_memory_map(dev, vq->avail_phys, vq->avail_size, false);
> if (!vq->avail) {
> r = -ENOMEM;
> goto fail;
> }
> -
> - l = vq->used_size;
> - vq->used = vhost_memory_map(dev, vq->used_phys, l, true);
> + vq->used = vhost_memory_map(dev, vq->used_phys, vq->used_size, true);
> if (!vq->used) {
> r = -ENOMEM;
> goto fail;
> --
> 2.52.0
>
>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 16/23] vhost: final refactoring of vhost vrings map/unmap
2026-01-19 18:52 ` [PATCH v4 16/23] vhost: final refactoring of vhost vrings map/unmap Vladimir Sementsov-Ogievskiy
@ 2026-01-19 23:50 ` Raphael Norwitz
0 siblings, 0 replies; 37+ messages in thread
From: Raphael Norwitz @ 2026-01-19 23:50 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
On Mon, Jan 19, 2026 at 1:55 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> Introduce helper functions vhost_vrings_map() and
> vhost_vrings_unmap() and use them.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/virtio/vhost.c | 89 +++++++++++++++++++++++++++++------------------
> 1 file changed, 55 insertions(+), 34 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 653cb706cc..7efdc4643d 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -489,6 +489,56 @@ static void vhost_memory_unmap(struct vhost_dev *dev, void **buffer,
> *buffer = NULL;
> }
>
> +static void vhost_vrings_unmap(struct vhost_dev *dev,
> + struct vhost_virtqueue *vq, bool touched)
> +{
> + vhost_memory_unmap(dev, &vq->used, vq->used_size, touched,
> + touched ? vq->used_size : 0);
> + vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0,
> + touched ? vq->avail_size : 0);
> + vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0,
> + touched ? vq->desc_size : 0);
> +}
> +
> +static int vhost_vrings_map(struct vhost_dev *dev,
> + struct VirtIODevice *vdev,
> + struct vhost_virtqueue *vq,
> + unsigned idx)
> +{
> + vq->desc_size = virtio_queue_get_desc_size(vdev, idx);
> + vq->desc_phys = virtio_queue_get_desc_addr(vdev, idx);
> + vq->desc = NULL;
> + vq->avail_size = virtio_queue_get_avail_size(vdev, idx);
> + vq->avail_phys = virtio_queue_get_avail_addr(vdev, idx);
> + vq->avail = NULL;
> + vq->used_size = virtio_queue_get_used_size(vdev, idx);
> + vq->used_phys = virtio_queue_get_used_addr(vdev, idx);
> + vq->used = NULL;
> +
> + if (vq->desc_phys == 0) {
> + /* Queue might not be ready for start */
> + return 0;
> + }
> + vq->desc = vhost_memory_map(dev, vq->desc_phys, vq->desc_size, false);
> + if (!vq->desc) {
> + goto fail;
> + }
> + vq->avail = vhost_memory_map(dev, vq->avail_phys, vq->avail_size, false);
> + if (!vq->avail) {
> + goto fail;
> + }
> + vq->used = vhost_memory_map(dev, vq->used_phys, vq->used_size, true);
> + if (!vq->used) {
> + goto fail;
> + }
> +
> + return 1;
> +
> +fail:
> + vhost_vrings_unmap(dev, vq, false);
> + return -ENOMEM;
> +}
> +
> static int vhost_verify_ring_part_mapping(void *ring_hva,
> uint64_t ring_gpa,
> uint64_t ring_size,
> @@ -1287,34 +1337,9 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
> };
> struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
>
> - vq->desc_size = virtio_queue_get_desc_size(vdev, idx);
> - vq->desc_phys = virtio_queue_get_desc_addr(vdev, idx);
> - vq->desc = NULL;
> - vq->avail_size = virtio_queue_get_avail_size(vdev, idx);
> - vq->avail_phys = virtio_queue_get_avail_addr(vdev, idx);
> - vq->avail = NULL;
> - vq->used_size = virtio_queue_get_used_size(vdev, idx);
> - vq->used_phys = virtio_queue_get_used_addr(vdev, idx);
> - vq->used = NULL;
> -
> - if (vq->desc_phys == 0) {
> - /* Queue might not be ready for start */
> - return 0;
> - }
> - vq->desc = vhost_memory_map(dev, vq->desc_phys, vq->desc_size, false);
> - if (!vq->desc) {
> - r = -ENOMEM;
> - goto fail;
> - }
> - vq->avail = vhost_memory_map(dev, vq->avail_phys, vq->avail_size, false);
> - if (!vq->avail) {
> - r = -ENOMEM;
> - goto fail;
> - }
> - vq->used = vhost_memory_map(dev, vq->used_phys, vq->used_size, true);
> - if (!vq->used) {
> - r = -ENOMEM;
> - goto fail;
> + r = vhost_vrings_map(dev, vdev, vq, idx);
> + if (r <= 0) {
> + return r;
> }
>
> vq->num = state.num = virtio_queue_get_num(vdev, idx);
> @@ -1376,9 +1401,7 @@ int vhost_virtqueue_start(struct vhost_dev *dev,
> return 0;
>
> fail:
> - vhost_memory_unmap(dev, &vq->used, vq->used_size, 0, 0);
> - vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0, 0);
> - vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0, 0);
> + vhost_vrings_unmap(dev, vq, false);
> return r;
> }
>
> @@ -1425,9 +1448,7 @@ static int do_vhost_virtqueue_stop(struct vhost_dev *dev,
> vhost_vq_index);
> }
>
> - vhost_memory_unmap(dev, &vq->used, vq->used_size, 1, vq->used_size);
> - vhost_memory_unmap(dev, &vq->avail, vq->avail_size, 0, vq->avail_size);
> - vhost_memory_unmap(dev, &vq->desc, vq->desc_size, 0, vq->desc_size);
> + vhost_vrings_unmap(dev, vq, true);
> return r;
> }
>
> --
> 2.52.0
>
>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 21/23] vhost-user: make trace events more readable
2026-01-19 18:52 ` [PATCH v4 21/23] vhost-user: make trace events more readable Vladimir Sementsov-Ogievskiy
@ 2026-01-19 23:50 ` Raphael Norwitz
0 siblings, 0 replies; 37+ messages in thread
From: Raphael Norwitz @ 2026-01-19 23:50 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin
Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
On Mon, Jan 19, 2026 at 1:55 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/virtio/trace-events | 4 +--
> hw/virtio/vhost-user.c | 63 ++++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 63 insertions(+), 4 deletions(-)
>
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 658cc365e7..aa1ffa5e94 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -25,8 +25,8 @@ vhost_user_set_mem_table_withfd(int index, const char *name, uint64_t memory_siz
> vhost_user_postcopy_waker(const char *rb, uint64_t rb_offset) "%s + 0x%"PRIx64
> vhost_user_postcopy_waker_found(uint64_t client_addr) "0x%"PRIx64
> vhost_user_postcopy_waker_nomatch(const char *rb, uint64_t rb_offset) "%s + 0x%"PRIx64
> -vhost_user_read(uint32_t req, uint32_t flags) "req:%d flags:0x%"PRIx32""
> -vhost_user_write(uint32_t req, uint32_t flags) "req:%d flags:0x%"PRIx32""
> +vhost_user_read(uint32_t req, const char *req_name, uint32_t flags) "req:%d (%s) flags:0x%"PRIx32""
> +vhost_user_write(uint32_t req, const char *req_name, uint32_t flags) "req:%d (%s) flags:0x%"PRIx32""
> vhost_user_create_notifier(int idx, void *n) "idx:%d n:%p"
>
> # vhost-vdpa.c
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index aedd5a80ff..824943f1eb 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -119,6 +119,63 @@ typedef enum VhostUserBackendRequest {
> VHOST_USER_BACKEND_MAX
> } VhostUserBackendRequest;
>
> +#define VHOST_USER_CASE(name) \
> + case VHOST_USER_##name: \
> + return #name;
> +
> +static const char *vhost_req_name(VhostUserRequest req)
> +{
> + switch (req) {
> + VHOST_USER_CASE(NONE)
> + VHOST_USER_CASE(GET_FEATURES)
> + VHOST_USER_CASE(SET_FEATURES)
> + VHOST_USER_CASE(SET_OWNER)
> + VHOST_USER_CASE(RESET_OWNER)
> + VHOST_USER_CASE(SET_MEM_TABLE)
> + VHOST_USER_CASE(SET_LOG_BASE)
> + VHOST_USER_CASE(SET_LOG_FD)
> + VHOST_USER_CASE(SET_VRING_NUM)
> + VHOST_USER_CASE(SET_VRING_ADDR)
> + VHOST_USER_CASE(SET_VRING_BASE)
> + VHOST_USER_CASE(GET_VRING_BASE)
> + VHOST_USER_CASE(SET_VRING_KICK)
> + VHOST_USER_CASE(SET_VRING_CALL)
> + VHOST_USER_CASE(SET_VRING_ERR)
> + VHOST_USER_CASE(GET_PROTOCOL_FEATURES)
> + VHOST_USER_CASE(SET_PROTOCOL_FEATURES)
> + VHOST_USER_CASE(GET_QUEUE_NUM)
> + VHOST_USER_CASE(SET_VRING_ENABLE)
> + VHOST_USER_CASE(SEND_RARP)
> + VHOST_USER_CASE(NET_SET_MTU)
> + VHOST_USER_CASE(SET_BACKEND_REQ_FD)
> + VHOST_USER_CASE(IOTLB_MSG)
> + VHOST_USER_CASE(SET_VRING_ENDIAN)
> + VHOST_USER_CASE(GET_CONFIG)
> + VHOST_USER_CASE(SET_CONFIG)
> + VHOST_USER_CASE(CREATE_CRYPTO_SESSION)
> + VHOST_USER_CASE(CLOSE_CRYPTO_SESSION)
> + VHOST_USER_CASE(POSTCOPY_ADVISE)
> + VHOST_USER_CASE(POSTCOPY_LISTEN)
> + VHOST_USER_CASE(POSTCOPY_END)
> + VHOST_USER_CASE(GET_INFLIGHT_FD)
> + VHOST_USER_CASE(SET_INFLIGHT_FD)
> + VHOST_USER_CASE(GPU_SET_SOCKET)
> + VHOST_USER_CASE(RESET_DEVICE)
> + VHOST_USER_CASE(GET_MAX_MEM_SLOTS)
> + VHOST_USER_CASE(ADD_MEM_REG)
> + VHOST_USER_CASE(REM_MEM_REG)
> + VHOST_USER_CASE(SET_STATUS)
> + VHOST_USER_CASE(GET_STATUS)
> + VHOST_USER_CASE(GET_SHARED_OBJECT)
> + VHOST_USER_CASE(SET_DEVICE_STATE_FD)
> + VHOST_USER_CASE(CHECK_DEVICE_STATE)
> + default:
> + return "<unknown>";
> + }
> +}
> +
> +#undef VHOST_USER_CASE
> +
> typedef struct VhostUserMemoryRegion {
> uint64_t guest_phys_addr;
> uint64_t memory_size;
> @@ -311,7 +368,8 @@ static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
> return -EPROTO;
> }
>
> - trace_vhost_user_read(msg->hdr.request, msg->hdr.flags);
> + trace_vhost_user_read(msg->hdr.request,
> + vhost_req_name(msg->hdr.request), msg->hdr.flags);
>
> return 0;
> }
> @@ -431,7 +489,8 @@ static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
> return ret < 0 ? -saved_errno : -EIO;
> }
>
> - trace_vhost_user_write(msg->hdr.request, msg->hdr.flags);
> + trace_vhost_user_write(msg->hdr.request, vhost_req_name(msg->hdr.request),
> + msg->hdr.flags);
>
> return 0;
> }
> --
> 2.52.0
>
>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path
2026-01-19 18:52 ` [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path Vladimir Sementsov-Ogievskiy
@ 2026-01-20 7:30 ` Thomas Huth
2026-01-20 21:18 ` Eric Farman
2026-01-21 10:39 ` Halil Pasic
2 siblings, 0 replies; 37+ messages in thread
From: Thomas Huth @ 2026-01-20 7:30 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy, mst
Cc: sgarzare, raphael, qemu-devel, yc-core, d-tatianin, Cornelia Huck,
Halil Pasic, Eric Farman, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Christian Borntraeger, Matthew Rosato,
open list:virtio-ccw
On 19/01/2026 19.52, Vladimir Sementsov-Ogievskiy wrote:
> We leak notifier initialization on that failure path. Let's
> cleanup it.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/s390x/virtio-ccw.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 6855e20d09..ba55bf4fe9 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -1038,6 +1038,7 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
> if (r) {
> virtio_queue_set_guest_notifier_fd_handler(vq, false,
> with_irqfd);
> + event_notifier_cleanup(notifier);
> return r;
> }
> }
Reviewed-by: Thomas Huth <thuth@redhat.com>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path
2026-01-19 18:52 ` [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path Vladimir Sementsov-Ogievskiy
2026-01-20 7:30 ` Thomas Huth
@ 2026-01-20 21:18 ` Eric Farman
2026-01-21 10:39 ` Halil Pasic
2 siblings, 0 replies; 37+ messages in thread
From: Eric Farman @ 2026-01-20 21:18 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy, mst
Cc: sgarzare, raphael, qemu-devel, yc-core, d-tatianin, Cornelia Huck,
Halil Pasic, Thomas Huth, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Christian Borntraeger, Matthew Rosato,
open list:virtio-ccw
On Mon, 2026-01-19 at 21:52 +0300, Vladimir Sementsov-Ogievskiy wrote:
> We leak notifier initialization on that failure path. Let's
> cleanup it.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/s390x/virtio-ccw.c | 1 +
> 1 file changed, 1 insertion(+)
Reviewed-by: Eric Farman <farman@linux.ibm.com>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-19 18:52 ` [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code Vladimir Sementsov-Ogievskiy
@ 2026-01-20 21:20 ` Eric Farman
2026-01-23 23:06 ` Halil Pasic
1 sibling, 0 replies; 37+ messages in thread
From: Eric Farman @ 2026-01-20 21:20 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy, mst
Cc: sgarzare, raphael, qemu-devel, yc-core, d-tatianin, Cornelia Huck,
Halil Pasic, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Thomas Huth, Christian Borntraeger,
Matthew Rosato, open list:virtio-ccw
On Mon, 2026-01-19 at 21:52 +0300, Vladimir Sementsov-Ogievskiy wrote:
> virtio-pci, virtio-mmio and virtio-ccw handle config notifier equally
> but with different code (mmio adds a separate function, when pci use
> common function). Let's chose the more compact way (pci) and reuse it
> for mmio.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> hw/s390x/virtio-ccw.c | 35 ++++++++++++-------------
> hw/virtio/virtio-mmio.c | 41 +++++------------------------
> hw/virtio/virtio-pci.c | 34 +++---------------------
> hw/virtio/virtio.c | 48 +++++++++++++++++++++++++++++++---
> include/hw/virtio/virtio-pci.h | 3 ---
> include/hw/virtio/virtio.h | 16 +++++++++---
> 6 files changed, 84 insertions(+), 93 deletions(-)
Acked-by: Eric Farman <farman@linux.ibm.com> # s390
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path
2026-01-19 18:52 ` [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path Vladimir Sementsov-Ogievskiy
2026-01-20 7:30 ` Thomas Huth
2026-01-20 21:18 ` Eric Farman
@ 2026-01-21 10:39 ` Halil Pasic
2 siblings, 0 replies; 37+ messages in thread
From: Halil Pasic @ 2026-01-21 10:39 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin,
Cornelia Huck, Eric Farman, Thomas Huth, Richard Henderson,
Ilya Leoshkevich, David Hildenbrand, Christian Borntraeger,
Matthew Rosato, open list:virtio-ccw, Halil Pasic
On Mon, 19 Jan 2026 21:52:11 +0300
Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
> We leak notifier initialization on that failure path. Let's
> cleanup it.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-19 18:52 ` [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code Vladimir Sementsov-Ogievskiy
2026-01-20 21:20 ` Eric Farman
@ 2026-01-23 23:06 ` Halil Pasic
2026-01-26 16:40 ` Vladimir Sementsov-Ogievskiy
1 sibling, 1 reply; 37+ messages in thread
From: Halil Pasic @ 2026-01-23 23:06 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin,
Cornelia Huck, Eric Farman, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Thomas Huth, Christian Borntraeger,
Matthew Rosato, open list:virtio-ccw, Halil Pasic
On Mon, 19 Jan 2026 21:52:12 +0300
Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
> virtio-pci, virtio-mmio and virtio-ccw handle config notifier equally
> but with different code (mmio adds a separate function, when pci use
> common function). Let's chose the more compact way (pci) and reuse it
> for mmio.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Ultimately is up to Michael to decide, but I'm not sure patch makes
things cleaner. I would even say, its current form, it does not.
I do like the idea of getting rid of duplicated logic though.
> ---
> hw/s390x/virtio-ccw.c | 35 ++++++++++++-------------
> hw/virtio/virtio-mmio.c | 41 +++++------------------------
> hw/virtio/virtio-pci.c | 34 +++---------------------
> hw/virtio/virtio.c | 48 +++++++++++++++++++++++++++++++---
> include/hw/virtio/virtio-pci.h | 3 ---
> include/hw/virtio/virtio.h | 16 +++++++++---
> 6 files changed, 84 insertions(+), 93 deletions(-)
[..]
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 3dc9423eae..ea43ea620c 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
[..]
> +static void virtio_pci_set_guest_notifier_fd_handler(VirtIODevice *vdev,
Function name says 'pci' but it actually is not PCI specific.
> + VirtQueue *vq,
> + int n, bool assign,
> + bool with_irqfd)
> +{
> + if (n == VIRTIO_CONFIG_IRQ_IDX) {
> + virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
> + } else {
> + virtio_queue_set_guest_notifier_fd_handler(vq, assign, with_irqfd);
> + }
> +}
> +
[..]
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index 27cd98d2fe..25ef7c9dff 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -420,8 +420,6 @@ void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
> VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
> uint16_t virtio_get_queue_index(VirtQueue *vq);
> EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
> -void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
> - bool with_irqfd);
> int virtio_device_start_ioeventfd(VirtIODevice *vdev);
> int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
> void virtio_device_release_ioeventfd(VirtIODevice *vdev);
> @@ -435,8 +433,18 @@ void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
> VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
> VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
> EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev);
> -void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
> - bool assign, bool with_irqfd);
> +
> +/**
> + * virtio_queue_set_guest_notifier - set/unset queue or config guest
> + * notifier
> + *
> + * @vdev: the VirtIO device
> + * @n: queue number, or VIRTIO_CONFIG_IRQ_IDX to set config notifer
Semantically are mixing queue numbers and interrupt indexes here.
> + * @assign: true to set notifier, false to unset
> + * @with_irqfd: irqfd enabled
> + */
> +int virtio_queue_set_guest_notifier(VirtIODevice *vdev, int n, bool assign,
> + bool with_irqfd);
The name says 'queue' but it is not always queue any more.
Regards,
Halil
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-23 23:06 ` Halil Pasic
@ 2026-01-26 16:40 ` Vladimir Sementsov-Ogievskiy
2026-01-26 22:00 ` Halil Pasic
0 siblings, 1 reply; 37+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2026-01-26 16:40 UTC (permalink / raw)
To: Halil Pasic
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin,
Cornelia Huck, Eric Farman, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Thomas Huth, Christian Borntraeger,
Matthew Rosato, open list:virtio-ccw
On 24.01.26 02:06, Halil Pasic wrote:
> On Mon, 19 Jan 2026 21:52:12 +0300
> Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
>
>> virtio-pci, virtio-mmio and virtio-ccw handle config notifier equally
>> but with different code (mmio adds a separate function, when pci use
>> common function). Let's chose the more compact way (pci) and reuse it
>> for mmio.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
>
> Ultimately is up to Michael to decide, but I'm not sure patch makes
> things cleaner. I would even say, its current form, it does not.
>
> I do like the idea of getting rid of duplicated logic though.
>
>
>> ---
>> hw/s390x/virtio-ccw.c | 35 ++++++++++++-------------
>> hw/virtio/virtio-mmio.c | 41 +++++------------------------
>> hw/virtio/virtio-pci.c | 34 +++---------------------
>> hw/virtio/virtio.c | 48 +++++++++++++++++++++++++++++++---
>> include/hw/virtio/virtio-pci.h | 3 ---
>> include/hw/virtio/virtio.h | 16 +++++++++---
>> 6 files changed, 84 insertions(+), 93 deletions(-)
> [..]
>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>> index 3dc9423eae..ea43ea620c 100644
>> --- a/hw/virtio/virtio.c
>> +++ b/hw/virtio/virtio.c
> [..]
>> +static void virtio_pci_set_guest_notifier_fd_handler(VirtIODevice *vdev,
>
> Function name says 'pci' but it actually is not PCI specific.
Agree. Is "virtio_set_guest_notifier_fd_handler()" OK?
>
>> + VirtQueue *vq,
>> + int n, bool assign,
>> + bool with_irqfd)
>> +{
>> + if (n == VIRTIO_CONFIG_IRQ_IDX) {
>> + virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
>> + } else {
>> + virtio_queue_set_guest_notifier_fd_handler(vq, assign, with_irqfd);
>> + }
>> +}
>> +
> [..]
>> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
>> index 27cd98d2fe..25ef7c9dff 100644
>> --- a/include/hw/virtio/virtio.h
>> +++ b/include/hw/virtio/virtio.h
>> @@ -420,8 +420,6 @@ void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
>> VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
>> uint16_t virtio_get_queue_index(VirtQueue *vq);
>> EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
>> -void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
>> - bool with_irqfd);
>> int virtio_device_start_ioeventfd(VirtIODevice *vdev);
>> int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
>> void virtio_device_release_ioeventfd(VirtIODevice *vdev);
>> @@ -435,8 +433,18 @@ void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
>> VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
>> VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
>> EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev);
>> -void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
>> - bool assign, bool with_irqfd);
>> +
>> +/**
>> + * virtio_queue_set_guest_notifier - set/unset queue or config guest
>> + * notifier
>> + *
>> + * @vdev: the VirtIO device
>> + * @n: queue number, or VIRTIO_CONFIG_IRQ_IDX to set config notifer
>
> Semantically are mixing queue numbers and interrupt indexes here.
That's preexisting logic in virtio_pci_set_guest_notifier_fd_handler().
But, you are right, that's doesn't answer the question, is it good to share
the logic with mmio and ccw.
Is config notifier only pci specific, or similar feature may appear in future
for mmio and/or ccw?
I can try to keep config-notifier logic only in pci code.
Michael, what's better?
>
>> + * @assign: true to set notifier, false to unset
>> + * @with_irqfd: irqfd enabled
>> + */
>> +int virtio_queue_set_guest_notifier(VirtIODevice *vdev, int n, bool assign,
>> + bool with_irqfd);
>
> The name says 'queue' but it is not always queue any more.
Agree, should be "virtio_set_guest_notifier()" if we go that way.
>
> Regards,
> Halil
Thanks for reviewing!
--
Best regards,
Vladimir
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-26 16:40 ` Vladimir Sementsov-Ogievskiy
@ 2026-01-26 22:00 ` Halil Pasic
2026-01-30 15:33 ` Eric Farman
0 siblings, 1 reply; 37+ messages in thread
From: Halil Pasic @ 2026-01-26 22:00 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin,
Cornelia Huck, Eric Farman, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Thomas Huth, Christian Borntraeger,
Matthew Rosato, open list:virtio-ccw, Halil Pasic
On Mon, 26 Jan 2026 19:40:09 +0300
Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
> >> +/**
> >> + * virtio_queue_set_guest_notifier - set/unset queue or config guest
> >> + * notifier
> >> + *
> >> + * @vdev: the VirtIO device
> >> + * @n: queue number, or VIRTIO_CONFIG_IRQ_IDX to set config notifer
> >
> > Semantically are mixing queue numbers and interrupt indexes here.
>
> That's preexisting logic in virtio_pci_set_guest_notifier_fd_handler().
>
> But, you are right, that's doesn't answer the question, is it good to share
> the logic with mmio and ccw.
>
> Is config notifier only pci specific, or similar feature may appear in future
> for mmio and/or ccw?
AFAIR there is no notifier for ccw. A possible explanation for
that is, that AFAIK that config space notifications (device -> driver)
are always classic I/O interrupts while queue indicators can be so called
adapter I/O interrupts and irqfd is only available for adapter I/O
interrupts.
If you like you can have a look at
"4.3.2.6 Setting Up Indicators" in
https://docs.oasis-open.org/virtio/virtio/v1.3/csd01/virtio-v1.3-csd01.html#x1-1940003
I see no reason why virtio_config_guest_notifier_read() based, i.e
!irqfd virtio config notifier should not exist or would not work. And I
guess it is needed for certain vhost things. But nevertheless, I can't
find the place where a virtio-ccw config notifier is set up.
Eric, what is your opinion on this? My current thinking is that
virtio-ccw not having a config notifier is basically a bug.
Regards,
Halil
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-26 22:00 ` Halil Pasic
@ 2026-01-30 15:33 ` Eric Farman
2026-01-30 16:31 ` Cornelia Huck
0 siblings, 1 reply; 37+ messages in thread
From: Eric Farman @ 2026-01-30 15:33 UTC (permalink / raw)
To: Halil Pasic, Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin,
Cornelia Huck, Richard Henderson, Ilya Leoshkevich,
David Hildenbrand, Thomas Huth, Christian Borntraeger,
Matthew Rosato, open list:virtio-ccw
On Mon, 2026-01-26 at 23:00 +0100, Halil Pasic wrote:
> On Mon, 26 Jan 2026 19:40:09 +0300
> Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
>
> > > > +/**
> > > > + * virtio_queue_set_guest_notifier - set/unset queue or config guest
> > > > + * notifier
> > > > + *
> > > > + * @vdev: the VirtIO device
> > > > + * @n: queue number, or VIRTIO_CONFIG_IRQ_IDX to set config notifer
> > >
> > > Semantically are mixing queue numbers and interrupt indexes here.
> >
> > That's preexisting logic in virtio_pci_set_guest_notifier_fd_handler().
> >
> > But, you are right, that's doesn't answer the question, is it good to share
> > the logic with mmio and ccw.
> >
> > Is config notifier only pci specific, or similar feature may appear in future
> > for mmio and/or ccw?
>
> AFAIR there is no notifier for ccw. A possible explanation for
> that is, that AFAIK that config space notifications (device -> driver)
> are always classic I/O interrupts while queue indicators can be so called
> adapter I/O interrupts and irqfd is only available for adapter I/O
> interrupts.
>
> If you like you can have a look at
> "4.3.2.6 Setting Up Indicators" in
> https://docs.oasis-open.org/virtio/virtio/v1.3/csd01/virtio-v1.3-csd01.html#x1-1940003
>
> I see no reason why virtio_config_guest_notifier_read() based, i.e
> !irqfd virtio config notifier should not exist or would not work. And I
> guess it is needed for certain vhost things. But nevertheless, I can't
> find the place where a virtio-ccw config notifier is set up.
>
> Eric, what is your opinion on this? My current thinking is that
> virtio-ccw not having a config notifier is basically a bug.
(Sorry that I missed this; thanks for the ping, Halil)
Yeah, we don't have have such a config notifier and I don't recall the history behind it.
But I don't know that it's a bug; spec points out config notifications for ccw come as unsolicited
interrupts versus config notifier, so not having one is fine by me as far as this refactoring goes.
I'll add it to a list of things to play around with, though.
Thanks, Eric
^ permalink raw reply [flat|nested] 37+ messages in thread
* Re: [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code
2026-01-30 15:33 ` Eric Farman
@ 2026-01-30 16:31 ` Cornelia Huck
0 siblings, 0 replies; 37+ messages in thread
From: Cornelia Huck @ 2026-01-30 16:31 UTC (permalink / raw)
To: Eric Farman, Halil Pasic, Vladimir Sementsov-Ogievskiy
Cc: mst, sgarzare, raphael, qemu-devel, yc-core, d-tatianin,
Richard Henderson, Ilya Leoshkevich, David Hildenbrand,
Thomas Huth, Christian Borntraeger, Matthew Rosato,
open list:virtio-ccw
On Fri, Jan 30 2026, Eric Farman <farman@linux.ibm.com> wrote:
> On Mon, 2026-01-26 at 23:00 +0100, Halil Pasic wrote:
>> On Mon, 26 Jan 2026 19:40:09 +0300
>> Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
>>
>> > > > +/**
>> > > > + * virtio_queue_set_guest_notifier - set/unset queue or config guest
>> > > > + * notifier
>> > > > + *
>> > > > + * @vdev: the VirtIO device
>> > > > + * @n: queue number, or VIRTIO_CONFIG_IRQ_IDX to set config notifer
>> > >
>> > > Semantically are mixing queue numbers and interrupt indexes here.
>> >
>> > That's preexisting logic in virtio_pci_set_guest_notifier_fd_handler().
>> >
>> > But, you are right, that's doesn't answer the question, is it good to share
>> > the logic with mmio and ccw.
>> >
>> > Is config notifier only pci specific, or similar feature may appear in future
>> > for mmio and/or ccw?
>>
>> AFAIR there is no notifier for ccw. A possible explanation for
>> that is, that AFAIK that config space notifications (device -> driver)
>> are always classic I/O interrupts while queue indicators can be so called
>> adapter I/O interrupts and irqfd is only available for adapter I/O
>> interrupts.
>>
>> If you like you can have a look at
>> "4.3.2.6 Setting Up Indicators" in
>> https://docs.oasis-open.org/virtio/virtio/v1.3/csd01/virtio-v1.3-csd01.html#x1-1940003
>>
>> I see no reason why virtio_config_guest_notifier_read() based, i.e
>> !irqfd virtio config notifier should not exist or would not work. And I
>> guess it is needed for certain vhost things. But nevertheless, I can't
>> find the place where a virtio-ccw config notifier is set up.
>>
>> Eric, what is your opinion on this? My current thinking is that
>> virtio-ccw not having a config notifier is basically a bug.
>
> (Sorry that I missed this; thanks for the ping, Halil)
>
> Yeah, we don't have have such a config notifier and I don't recall the history behind it.
Adapter interrupts were not a thing for virtio-ccw in the beginning (we
only added the airq infrastructure later IIRC, so all interrupts were
"classic" subchannel-based interrupts.)
> But I don't know that it's a bug; spec points out config notifications for ccw come as unsolicited
> interrupts versus config notifier, so not having one is fine by me as far as this refactoring goes.
> I'll add it to a list of things to play around with, though.
I think I agree.
(Although my brain is already more than halfway into the weekend...)
^ permalink raw reply [flat|nested] 37+ messages in thread
end of thread, other threads:[~2026-01-30 16:32 UTC | newest]
Thread overview: 37+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-01-19 18:52 [PATCH v4 00/23] vhost refactoring and fixes Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 01/23] vhost-user: rework enabling vrings Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 02/23] vhost: drop backend_features field Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 03/23] vhost-user: introduce vhost_user_has_protocol_feature() helper Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 04/23] vhost: move protocol_features to vhost_user Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 05/23] vhost-user-gpu: drop code duplication Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 06/23] vhost: make vhost_dev.features private Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 07/23] virtio-ccw: virtio_ccw_set_guest_notifier(): fix failure path Vladimir Sementsov-Ogievskiy
2026-01-20 7:30 ` Thomas Huth
2026-01-20 21:18 ` Eric Farman
2026-01-21 10:39 ` Halil Pasic
2026-01-19 18:52 ` [PATCH v4 08/23] virtio: move common part of _set_guest_notifier to generic code Vladimir Sementsov-Ogievskiy
2026-01-20 21:20 ` Eric Farman
2026-01-23 23:06 ` Halil Pasic
2026-01-26 16:40 ` Vladimir Sementsov-Ogievskiy
2026-01-26 22:00 ` Halil Pasic
2026-01-30 15:33 ` Eric Farman
2026-01-30 16:31 ` Cornelia Huck
2026-01-19 18:52 ` [PATCH v4 09/23] virtio: drop *_set_guest_notifier_fd_handler() helpers Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 10/23] vhost-user: keep QIOChannelSocket for backend channel Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 11/23] vhost: vhost_virtqueue_start(): fix failure path Vladimir Sementsov-Ogievskiy
2026-01-19 23:49 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 12/23] vhost: make vhost_memory_unmap() null-safe Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 13/23] vhost: simplify calls to vhost_memory_unmap() Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 14/23] vhost: move vrings mapping to the top of vhost_virtqueue_start() Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 15/23] vhost: vhost_virtqueue_start(): drop extra local variables Vladimir Sementsov-Ogievskiy
2026-01-19 23:49 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 16/23] vhost: final refactoring of vhost vrings map/unmap Vladimir Sementsov-Ogievskiy
2026-01-19 23:50 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 17/23] vhost: simplify vhost_dev_init() error-path Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 18/23] vhost: move busyloop timeout initialization to vhost_virtqueue_init() Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 19/23] vhost: vhost_dev_init(): simplify features initialization Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 20/23] hw/virtio/virtio-bus: refactor virtio_bus_set_host_notifier() Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 21/23] vhost-user: make trace events more readable Vladimir Sementsov-Ogievskiy
2026-01-19 23:50 ` Raphael Norwitz
2026-01-19 18:52 ` [PATCH v4 22/23] vhost-user-blk: add some useful trace-points Vladimir Sementsov-Ogievskiy
2026-01-19 18:52 ` [PATCH v4 23/23] vhost: " Vladimir Sementsov-Ogievskiy
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