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>
---
backends/cryptodev-vhost.c | 1 -
hw/net/vhost_net.c | 2 --
hw/virtio/vhost-user.c | 23 ++++++++++++++++++++---
hw/virtio/virtio-qmp.c | 6 ++++--
include/hw/virtio/vhost-backend.h | 3 +++
include/hw/virtio/vhost.h | 8 --------
6 files changed, 27 insertions(+), 16 deletions(-)
diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
index 943680a23a..3bcdc494d8 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 fcee279f0b..ce30b6e197 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -260,9 +260,7 @@ 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 6fa5b8a8bd..abdf47ee7b 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 {
@@ -274,7 +283,8 @@ struct scrub_regions {
static bool vhost_user_has_prot(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)
@@ -2218,8 +2228,8 @@ 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;
@@ -3001,6 +3011,12 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
return 0;
}
+static void vhost_user_qmp_status(struct vhost_dev *dev, VhostStatus *status)
+{
+ struct vhost_user *u = dev->opaque;
+ status->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,
@@ -3041,4 +3057,5 @@ const VhostOps user_ops = {
.vhost_supports_device_state = vhost_user_supports_device_state,
.vhost_set_device_state_fd = vhost_user_set_device_state_fd,
.vhost_check_device_state = vhost_user_check_device_state,
+ .vhost_qmp_status = vhost_user_qmp_status,
};
diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
index e514a4797e..d55b12f9f3 100644
--- a/hw/virtio/virtio-qmp.c
+++ b/hw/virtio/virtio-qmp.c
@@ -788,12 +788,14 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
qmp_decode_features(vdev->device_id, hdev->features);
status->vhost_dev->acked_features =
qmp_decode_features(vdev->device_id, hdev->acked_features);
- 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->vhost_qmp_status) {
+ hdev->vhost_ops->vhost_qmp_status(hdev, status->vhost_dev);
+ }
}
return status;
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index f65fa26298..0785fc764d 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -12,6 +12,7 @@
#define VHOST_BACKEND_H
#include "system/memory.h"
+#include "qapi/qapi-commands-virtio.h"
typedef enum VhostBackendType {
VHOST_BACKEND_TYPE_NONE = 0,
@@ -160,6 +161,7 @@ typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
int *reply_fd,
Error **errp);
typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
+typedef void (*vhost_qmp_status_op)(struct vhost_dev *dev, VhostStatus *status);
typedef struct VhostOps {
VhostBackendType backend_type;
@@ -216,6 +218,7 @@ typedef struct VhostOps {
vhost_supports_device_state_op vhost_supports_device_state;
vhost_set_device_state_fd_op vhost_set_device_state_fd;
vhost_check_device_state_op vhost_check_device_state;
+ vhost_qmp_status_op vhost_qmp_status;
} VhostOps;
int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 9f9dd2d46d..15bc287a9d 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -104,14 +104,6 @@ struct vhost_dev {
uint64_t features;
uint64_t 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? */
--
2.48.1On Wed, Aug 13, 2025 at 12:57 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> 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>
> ---
> backends/cryptodev-vhost.c | 1 -
> hw/net/vhost_net.c | 2 --
> hw/virtio/vhost-user.c | 23 ++++++++++++++++++++---
> hw/virtio/virtio-qmp.c | 6 ++++--
> include/hw/virtio/vhost-backend.h | 3 +++
> include/hw/virtio/vhost.h | 8 --------
> 6 files changed, 27 insertions(+), 16 deletions(-)
>
> diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
> index 943680a23a..3bcdc494d8 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 fcee279f0b..ce30b6e197 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -260,9 +260,7 @@ 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 6fa5b8a8bd..abdf47ee7b 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 {
> @@ -274,7 +283,8 @@ struct scrub_regions {
>
> static bool vhost_user_has_prot(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)
> @@ -2218,8 +2228,8 @@ 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;
> @@ -3001,6 +3011,12 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
> return 0;
> }
>
> +static void vhost_user_qmp_status(struct vhost_dev *dev, VhostStatus *status)
> +{
> + struct vhost_user *u = dev->opaque;
> + status->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,
> @@ -3041,4 +3057,5 @@ const VhostOps user_ops = {
> .vhost_supports_device_state = vhost_user_supports_device_state,
> .vhost_set_device_state_fd = vhost_user_set_device_state_fd,
> .vhost_check_device_state = vhost_user_check_device_state,
> + .vhost_qmp_status = vhost_user_qmp_status,
> };
> diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
> index e514a4797e..d55b12f9f3 100644
> --- a/hw/virtio/virtio-qmp.c
> +++ b/hw/virtio/virtio-qmp.c
> @@ -788,12 +788,14 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
> qmp_decode_features(vdev->device_id, hdev->features);
> status->vhost_dev->acked_features =
> qmp_decode_features(vdev->device_id, hdev->acked_features);
> - 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->vhost_qmp_status) {
> + hdev->vhost_ops->vhost_qmp_status(hdev, status->vhost_dev);
> + }
Same comment as patch 1/33 - why have it in vhost_ops if it is
vhost_user specific, rather than checking the backend type and calling
a helper?
> }
>
> return status;
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index f65fa26298..0785fc764d 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -12,6 +12,7 @@
> #define VHOST_BACKEND_H
>
> #include "system/memory.h"
> +#include "qapi/qapi-commands-virtio.h"
>
> typedef enum VhostBackendType {
> VHOST_BACKEND_TYPE_NONE = 0,
> @@ -160,6 +161,7 @@ typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
> int *reply_fd,
> Error **errp);
> typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
> +typedef void (*vhost_qmp_status_op)(struct vhost_dev *dev, VhostStatus *status);
>
> typedef struct VhostOps {
> VhostBackendType backend_type;
> @@ -216,6 +218,7 @@ typedef struct VhostOps {
> vhost_supports_device_state_op vhost_supports_device_state;
> vhost_set_device_state_fd_op vhost_set_device_state_fd;
> vhost_check_device_state_op vhost_check_device_state;
> + vhost_qmp_status_op vhost_qmp_status;
> } VhostOps;
>
> int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 9f9dd2d46d..15bc287a9d 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -104,14 +104,6 @@ struct vhost_dev {
> uint64_t features;
> uint64_t 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? */
> --
> 2.48.1
>
>
On 09.10.25 21:57, Raphael Norwitz wrote:
> On Wed, Aug 13, 2025 at 12:57 PM Vladimir Sementsov-Ogievskiy
> <vsementsov@yandex-team.ru> wrote:
>>
>> 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>
>> ---
>> backends/cryptodev-vhost.c | 1 -
>> hw/net/vhost_net.c | 2 --
>> hw/virtio/vhost-user.c | 23 ++++++++++++++++++++---
>> hw/virtio/virtio-qmp.c | 6 ++++--
>> include/hw/virtio/vhost-backend.h | 3 +++
>> include/hw/virtio/vhost.h | 8 --------
>> 6 files changed, 27 insertions(+), 16 deletions(-)
>>
>> diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
>> index 943680a23a..3bcdc494d8 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 fcee279f0b..ce30b6e197 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -260,9 +260,7 @@ 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 6fa5b8a8bd..abdf47ee7b 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 {
>> @@ -274,7 +283,8 @@ struct scrub_regions {
>>
>> static bool vhost_user_has_prot(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)
>> @@ -2218,8 +2228,8 @@ 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;
>> @@ -3001,6 +3011,12 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
>> return 0;
>> }
>>
>> +static void vhost_user_qmp_status(struct vhost_dev *dev, VhostStatus *status)
>> +{
>> + struct vhost_user *u = dev->opaque;
>> + status->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,
>> @@ -3041,4 +3057,5 @@ const VhostOps user_ops = {
>> .vhost_supports_device_state = vhost_user_supports_device_state,
>> .vhost_set_device_state_fd = vhost_user_set_device_state_fd,
>> .vhost_check_device_state = vhost_user_check_device_state,
>> + .vhost_qmp_status = vhost_user_qmp_status,
>> };
>> diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
>> index e514a4797e..d55b12f9f3 100644
>> --- a/hw/virtio/virtio-qmp.c
>> +++ b/hw/virtio/virtio-qmp.c
>> @@ -788,12 +788,14 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
>> qmp_decode_features(vdev->device_id, hdev->features);
>> status->vhost_dev->acked_features =
>> qmp_decode_features(vdev->device_id, hdev->acked_features);
>> - 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->vhost_qmp_status) {
>> + hdev->vhost_ops->vhost_qmp_status(hdev, status->vhost_dev);
>> + }
>
> Same comment as patch 1/33 - why have it in vhost_ops if it is
> vhost_user specific, rather than checking the backend type and calling
> a helper?
>
Aha, I think now, I undestand you correctly in 1/33.
No specific reason, but a try to keep generic code backend-agnostic, without
knowledge about specific backends.
Not a problem for me to swith to "if (backend_type == ", if it's preferable
in this case.
>
>> }
>>
>> return status;
>> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
>> index f65fa26298..0785fc764d 100644
>> --- a/include/hw/virtio/vhost-backend.h
>> +++ b/include/hw/virtio/vhost-backend.h
>> @@ -12,6 +12,7 @@
>> #define VHOST_BACKEND_H
>>
>> #include "system/memory.h"
>> +#include "qapi/qapi-commands-virtio.h"
>>
>> typedef enum VhostBackendType {
>> VHOST_BACKEND_TYPE_NONE = 0,
>> @@ -160,6 +161,7 @@ typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
>> int *reply_fd,
>> Error **errp);
>> typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
>> +typedef void (*vhost_qmp_status_op)(struct vhost_dev *dev, VhostStatus *status);
>>
>> typedef struct VhostOps {
>> VhostBackendType backend_type;
>> @@ -216,6 +218,7 @@ typedef struct VhostOps {
>> vhost_supports_device_state_op vhost_supports_device_state;
>> vhost_set_device_state_fd_op vhost_set_device_state_fd;
>> vhost_check_device_state_op vhost_check_device_state;
>> + vhost_qmp_status_op vhost_qmp_status;
>> } VhostOps;
>>
>> int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>> index 9f9dd2d46d..15bc287a9d 100644
>> --- a/include/hw/virtio/vhost.h
>> +++ b/include/hw/virtio/vhost.h
>> @@ -104,14 +104,6 @@ struct vhost_dev {
>> uint64_t features;
>> uint64_t 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? */
>> --
>> 2.48.1
>>
>>
--
Best regards,
Vladimir
On Thu, Oct 9, 2025 at 3:35 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> On 09.10.25 21:57, Raphael Norwitz wrote:
> > On Wed, Aug 13, 2025 at 12:57 PM Vladimir Sementsov-Ogievskiy
> > <vsementsov@yandex-team.ru> wrote:
> >>
> >> 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>
> >> ---
> >> backends/cryptodev-vhost.c | 1 -
> >> hw/net/vhost_net.c | 2 --
> >> hw/virtio/vhost-user.c | 23 ++++++++++++++++++++---
> >> hw/virtio/virtio-qmp.c | 6 ++++--
> >> include/hw/virtio/vhost-backend.h | 3 +++
> >> include/hw/virtio/vhost.h | 8 --------
> >> 6 files changed, 27 insertions(+), 16 deletions(-)
> >>
> >> diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
> >> index 943680a23a..3bcdc494d8 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 fcee279f0b..ce30b6e197 100644
> >> --- a/hw/net/vhost_net.c
> >> +++ b/hw/net/vhost_net.c
> >> @@ -260,9 +260,7 @@ 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 6fa5b8a8bd..abdf47ee7b 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 {
> >> @@ -274,7 +283,8 @@ struct scrub_regions {
> >>
> >> static bool vhost_user_has_prot(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)
> >> @@ -2218,8 +2228,8 @@ 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;
> >> @@ -3001,6 +3011,12 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
> >> return 0;
> >> }
> >>
> >> +static void vhost_user_qmp_status(struct vhost_dev *dev, VhostStatus *status)
> >> +{
> >> + struct vhost_user *u = dev->opaque;
> >> + status->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,
> >> @@ -3041,4 +3057,5 @@ const VhostOps user_ops = {
> >> .vhost_supports_device_state = vhost_user_supports_device_state,
> >> .vhost_set_device_state_fd = vhost_user_set_device_state_fd,
> >> .vhost_check_device_state = vhost_user_check_device_state,
> >> + .vhost_qmp_status = vhost_user_qmp_status,
> >> };
> >> diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
> >> index e514a4797e..d55b12f9f3 100644
> >> --- a/hw/virtio/virtio-qmp.c
> >> +++ b/hw/virtio/virtio-qmp.c
> >> @@ -788,12 +788,14 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
> >> qmp_decode_features(vdev->device_id, hdev->features);
> >> status->vhost_dev->acked_features =
> >> qmp_decode_features(vdev->device_id, hdev->acked_features);
> >> - 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->vhost_qmp_status) {
> >> + hdev->vhost_ops->vhost_qmp_status(hdev, status->vhost_dev);
> >> + }
> >
> > Same comment as patch 1/33 - why have it in vhost_ops if it is
> > vhost_user specific, rather than checking the backend type and calling
> > a helper?
> >
>
> Aha, I think now, I undestand you correctly in 1/33.
>
> No specific reason, but a try to keep generic code backend-agnostic, without
> knowledge about specific backends.
>
> Not a problem for me to swith to "if (backend_type == ", if it's preferable
> in this case.
>
Yes, that is what I meant. I think it makes the code more readable but
if others disagree we can leave it.
> >
> >> }
> >>
> >> return status;
> >> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> >> index f65fa26298..0785fc764d 100644
> >> --- a/include/hw/virtio/vhost-backend.h
> >> +++ b/include/hw/virtio/vhost-backend.h
> >> @@ -12,6 +12,7 @@
> >> #define VHOST_BACKEND_H
> >>
> >> #include "system/memory.h"
> >> +#include "qapi/qapi-commands-virtio.h"
> >>
> >> typedef enum VhostBackendType {
> >> VHOST_BACKEND_TYPE_NONE = 0,
> >> @@ -160,6 +161,7 @@ typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
> >> int *reply_fd,
> >> Error **errp);
> >> typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
> >> +typedef void (*vhost_qmp_status_op)(struct vhost_dev *dev, VhostStatus *status);
> >>
> >> typedef struct VhostOps {
> >> VhostBackendType backend_type;
> >> @@ -216,6 +218,7 @@ typedef struct VhostOps {
> >> vhost_supports_device_state_op vhost_supports_device_state;
> >> vhost_set_device_state_fd_op vhost_set_device_state_fd;
> >> vhost_check_device_state_op vhost_check_device_state;
> >> + vhost_qmp_status_op vhost_qmp_status;
> >> } VhostOps;
> >>
> >> int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
> >> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> >> index 9f9dd2d46d..15bc287a9d 100644
> >> --- a/include/hw/virtio/vhost.h
> >> +++ b/include/hw/virtio/vhost.h
> >> @@ -104,14 +104,6 @@ struct vhost_dev {
> >> uint64_t features;
> >> uint64_t 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? */
> >> --
> >> 2.48.1
> >>
> >>
>
>
> --
> Best regards,
> Vladimir
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