Re: [PATCH] vdpa/mlx5: should keep avail_index despite device status

[Jason Wang]

On 2020/10/2 上午4:18, Si-Wei Liu wrote:

A VM with mlx5 vDPA has below warnings while being reset:

vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)

We should allow userspace emulating the virtio device be
able to get to vq's avail_index, regardless of vDPA device
status. Save the index that was last seen when virtq was
stopped, so that userspace doesn't complain.

Signed-off-by: Si-Wei Liu 



Acked-by: Jason Wang 



---
  drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++--
  1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 70676a6..74264e59 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, 
struct mlx5_vdpa_virtqueue *m
if (!mvq->initialized)
return;
  
-	if (query_virtqueue(ndev, mvq, )) {

-   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
-   return;
-   }
if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
return;
  
  	if (modify_virtqueue(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))

mlx5_vdpa_warn(>mvdev, "modify to suspend failed\n");
+
+   if (query_virtqueue(ndev, mvq, )) {
+   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
+   return;
+   }
+   mvq->avail_idx = attr.available_index;
  }
  
  static void suspend_vqs(struct mlx5_vdpa_net *ndev)

@@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device 
*vdev, u16 idx, struct vdpa
struct mlx5_virtq_attr attr;
int err;
  
-	if (!mvq->initialized)

-   return -EAGAIN;
+   /* If the virtq object was destroyed, use the value saved at
+* the last minute of suspend_vq. This caters for userspace
+* that cares about emulating the index after vq is stopped.
+*/
+   if (!mvq->initialized) {
+   state->avail_index = mvq->avail_idx;
+   return 0;
+   }
  
  	err = query_virtqueue(ndev, mvq, );

if (err) {

Re: [PATCH] vdpa/mlx5: should keep avail_index despite device status

[Eli Cohen]

On Tue, Oct 06, 2020 at 02:22:15AM -0400, Michael S. Tsirkin wrote:

Acked-by: Eli Cohen 

> On Fri, Oct 02, 2020 at 01:17:00PM -0700, Si-Wei Liu wrote:
> > + Eli.
> > 
> > On Thu, Oct 1, 2020 at 2:02 PM Si-Wei Liu  wrote:
> > >
> > > A VM with mlx5 vDPA has below warnings while being reset:
> > >
> > > vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
> > > vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)
> > >
> > > We should allow userspace emulating the virtio device be
> > > able to get to vq's avail_index, regardless of vDPA device
> > > status. Save the index that was last seen when virtq was
> > > stopped, so that userspace doesn't complain.
> > >
> > > Signed-off-by: Si-Wei Liu 
> 
> Eli can you review this pls? I need to send a pull request to Linux by
> tomorrow - do we want to include this?
> 
> > > ---
> > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++--
> > >  1 file changed, 14 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > index 70676a6..74264e59 100644
> > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > @@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net 
> > > *ndev, struct mlx5_vdpa_virtqueue *m
> > > if (!mvq->initialized)
> > > return;
> > >
> > > -   if (query_virtqueue(ndev, mvq, )) {
> > > -   mlx5_vdpa_warn(>mvdev, "failed to query 
> > > virtqueue\n");
> > > -   return;
> > > -   }
> > > if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
> > > return;
> > >
> > > if (modify_virtqueue(ndev, mvq, 
> > > MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))
> > > mlx5_vdpa_warn(>mvdev, "modify to suspend 
> > > failed\n");
> > > +
> > > +   if (query_virtqueue(ndev, mvq, )) {
> > > +   mlx5_vdpa_warn(>mvdev, "failed to query 
> > > virtqueue\n");
> > > +   return;
> > > +   }
> > > +   mvq->avail_idx = attr.available_index;
> > >  }
> > >
> > >  static void suspend_vqs(struct mlx5_vdpa_net *ndev)
> > > @@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct 
> > > vdpa_device *vdev, u16 idx, struct vdpa
> > > struct mlx5_virtq_attr attr;
> > > int err;
> > >
> > > -   if (!mvq->initialized)
> > > -   return -EAGAIN;
> > > +   /* If the virtq object was destroyed, use the value saved at
> > > +* the last minute of suspend_vq. This caters for userspace
> > > +* that cares about emulating the index after vq is stopped.
> > > +*/
> > > +   if (!mvq->initialized) {
> > > +   state->avail_index = mvq->avail_idx;
> > > +   return 0;
> > > +   }
> > >
> > > err = query_virtqueue(ndev, mvq, );
> > > if (err) {
> > > --
> > > 1.8.3.1
> > >
> 

Re: [PATCH] vdpa/mlx5: should keep avail_index despite device status

[Michael S. Tsirkin]

On Fri, Oct 02, 2020 at 01:17:00PM -0700, Si-Wei Liu wrote:
> + Eli.
> 
> On Thu, Oct 1, 2020 at 2:02 PM Si-Wei Liu  wrote:
> >
> > A VM with mlx5 vDPA has below warnings while being reset:
> >
> > vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
> > vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)
> >
> > We should allow userspace emulating the virtio device be
> > able to get to vq's avail_index, regardless of vDPA device
> > status. Save the index that was last seen when virtq was
> > stopped, so that userspace doesn't complain.
> >
> > Signed-off-by: Si-Wei Liu 

Eli can you review this pls? I need to send a pull request to Linux by
tomorrow - do we want to include this?

> > ---
> >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++--
> >  1 file changed, 14 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index 70676a6..74264e59 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, 
> > struct mlx5_vdpa_virtqueue *m
> > if (!mvq->initialized)
> > return;
> >
> > -   if (query_virtqueue(ndev, mvq, )) {
> > -   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
> > -   return;
> > -   }
> > if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
> > return;
> >
> > if (modify_virtqueue(ndev, mvq, 
> > MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))
> > mlx5_vdpa_warn(>mvdev, "modify to suspend failed\n");
> > +
> > +   if (query_virtqueue(ndev, mvq, )) {
> > +   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
> > +   return;
> > +   }
> > +   mvq->avail_idx = attr.available_index;
> >  }
> >
> >  static void suspend_vqs(struct mlx5_vdpa_net *ndev)
> > @@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device 
> > *vdev, u16 idx, struct vdpa
> > struct mlx5_virtq_attr attr;
> > int err;
> >
> > -   if (!mvq->initialized)
> > -   return -EAGAIN;
> > +   /* If the virtq object was destroyed, use the value saved at
> > +* the last minute of suspend_vq. This caters for userspace
> > +* that cares about emulating the index after vq is stopped.
> > +*/
> > +   if (!mvq->initialized) {
> > +   state->avail_index = mvq->avail_idx;
> > +   return 0;
> > +   }
> >
> > err = query_virtqueue(ndev, mvq, );
> > if (err) {
> > --
> > 1.8.3.1
> >

Re: [PATCH] vdpa/mlx5: should keep avail_index despite device status

[Si-Wei Liu]

+ Eli.

On Thu, Oct 1, 2020 at 2:02 PM Si-Wei Liu  wrote:
>
> A VM with mlx5 vDPA has below warnings while being reset:
>
> vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
> vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)
>
> We should allow userspace emulating the virtio device be
> able to get to vq's avail_index, regardless of vDPA device
> status. Save the index that was last seen when virtq was
> stopped, so that userspace doesn't complain.
>
> Signed-off-by: Si-Wei Liu 
> ---
>  drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++--
>  1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 70676a6..74264e59 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, 
> struct mlx5_vdpa_virtqueue *m
> if (!mvq->initialized)
> return;
>
> -   if (query_virtqueue(ndev, mvq, )) {
> -   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
> -   return;
> -   }
> if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
> return;
>
> if (modify_virtqueue(ndev, mvq, 
> MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))
> mlx5_vdpa_warn(>mvdev, "modify to suspend failed\n");
> +
> +   if (query_virtqueue(ndev, mvq, )) {
> +   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
> +   return;
> +   }
> +   mvq->avail_idx = attr.available_index;
>  }
>
>  static void suspend_vqs(struct mlx5_vdpa_net *ndev)
> @@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device 
> *vdev, u16 idx, struct vdpa
> struct mlx5_virtq_attr attr;
> int err;
>
> -   if (!mvq->initialized)
> -   return -EAGAIN;
> +   /* If the virtq object was destroyed, use the value saved at
> +* the last minute of suspend_vq. This caters for userspace
> +* that cares about emulating the index after vq is stopped.
> +*/
> +   if (!mvq->initialized) {
> +   state->avail_index = mvq->avail_idx;
> +   return 0;
> +   }
>
> err = query_virtqueue(ndev, mvq, );
> if (err) {
> --
> 1.8.3.1
>

[PATCH] vdpa/mlx5: should keep avail_index despite device status

[Si-Wei Liu]

A VM with mlx5 vDPA has below warnings while being reset:

vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)

We should allow userspace emulating the virtio device be
able to get to vq's avail_index, regardless of vDPA device
status. Save the index that was last seen when virtq was
stopped, so that userspace doesn't complain.

Signed-off-by: Si-Wei Liu 
---
 drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++--
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 70676a6..74264e59 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, 
struct mlx5_vdpa_virtqueue *m
if (!mvq->initialized)
return;
 
-   if (query_virtqueue(ndev, mvq, )) {
-   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
-   return;
-   }
if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
return;
 
if (modify_virtqueue(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))
mlx5_vdpa_warn(>mvdev, "modify to suspend failed\n");
+
+   if (query_virtqueue(ndev, mvq, )) {
+   mlx5_vdpa_warn(>mvdev, "failed to query virtqueue\n");
+   return;
+   }
+   mvq->avail_idx = attr.available_index;
 }
 
 static void suspend_vqs(struct mlx5_vdpa_net *ndev)
@@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device 
*vdev, u16 idx, struct vdpa
struct mlx5_virtq_attr attr;
int err;
 
-   if (!mvq->initialized)
-   return -EAGAIN;
+   /* If the virtq object was destroyed, use the value saved at
+* the last minute of suspend_vq. This caters for userspace
+* that cares about emulating the index after vq is stopped.
+*/
+   if (!mvq->initialized) {
+   state->avail_index = mvq->avail_idx;
+   return 0;
+   }
 
err = query_virtqueue(ndev, mvq, );
if (err) {
-- 
1.8.3.1