diff mbox series

[v2,1/2] vdpa/mlx5: workaround FW first completion in start

Message ID 20211015150545.1673312-1-xuemingl@nvidia.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers show
Series [v2,1/2] vdpa/mlx5: workaround FW first completion in start | expand

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Xueming(Steven) Li Oct. 15, 2021, 3:05 p.m. UTC
After a vDPA application restart, qemu restores VQ with used and
available index, new incoming packet triggers virtio driver to
handle buffers. Under heavy traffic, no available buffer for
firmware to receive new packets, no Rx interrupts generated,
driver is stuck on endless interrupt waiting.

As a firmware workaround, this patch sends a notification after
VQ setup to ask driver handling buffers and filling new buffers.

Fixes: bff735011078 ("vdpa/mlx5: prepare virtio queues")
Cc: stable@dpdk.org

Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Reviewed-by: Matan Azrad <matan@nvidia.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa_virtq.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Maxime Coquelin Oct. 21, 2021, 9:40 a.m. UTC | #1
On 10/15/21 17:05, Xueming Li wrote:
> After a vDPA application restart, qemu restores VQ with used and
> available index, new incoming packet triggers virtio driver to
> handle buffers. Under heavy traffic, no available buffer for
> firmware to receive new packets, no Rx interrupts generated,
> driver is stuck on endless interrupt waiting.
> 
> As a firmware workaround, this patch sends a notification after
> VQ setup to ask driver handling buffers and filling new buffers.
> 
> Fixes: bff735011078 ("vdpa/mlx5: prepare virtio queues")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> Reviewed-by: Matan Azrad <matan@nvidia.com>
> ---
>   drivers/vdpa/mlx5/mlx5_vdpa_virtq.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime
Maxime Coquelin Oct. 21, 2021, 12:27 p.m. UTC | #2
On 10/15/21 17:05, Xueming Li wrote:
> After a vDPA application restart, qemu restores VQ with used and
> available index, new incoming packet triggers virtio driver to
> handle buffers. Under heavy traffic, no available buffer for
> firmware to receive new packets, no Rx interrupts generated,
> driver is stuck on endless interrupt waiting.
> 
> As a firmware workaround, this patch sends a notification after
> VQ setup to ask driver handling buffers and filling new buffers.
> 
> Fixes: bff735011078 ("vdpa/mlx5: prepare virtio queues")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> Reviewed-by: Matan Azrad <matan@nvidia.com>
> ---
>   drivers/vdpa/mlx5/mlx5_vdpa_virtq.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 


Applied to dpdk-next-virtio/main.

Thanks,
Maxime
Xueming(Steven) Li Oct. 21, 2021, 12:36 p.m. UTC | #3
On Thu, 2021-10-21 at 14:27 +0200, Maxime Coquelin wrote:
> 
> On 10/15/21 17:05, Xueming Li wrote:
> > After a vDPA application restart, qemu restores VQ with used and
> > available index, new incoming packet triggers virtio driver to
> > handle buffers. Under heavy traffic, no available buffer for
> > firmware to receive new packets, no Rx interrupts generated,
> > driver is stuck on endless interrupt waiting.
> > 
> > As a firmware workaround, this patch sends a notification after
> > VQ setup to ask driver handling buffers and filling new buffers.
> > 
> > Fixes: bff735011078 ("vdpa/mlx5: prepare virtio queues")
> > Cc: stable@dpdk.org
> > 
> > Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> > Reviewed-by: Matan Azrad <matan@nvidia.com>
> > ---
> >   drivers/vdpa/mlx5/mlx5_vdpa_virtq.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> 
> 
> Applied to dpdk-next-virtio/main.

Thanks Maxime!

> 
> Thanks,
> Maxime
>
diff mbox series

Patch

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
index f530646058f..71470d23d9e 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
@@ -4,6 +4,7 @@ 
 #include <string.h>
 #include <unistd.h>
 #include <sys/mman.h>
+#include <sys/eventfd.h>
 
 #include <rte_malloc.h>
 #include <rte_errno.h>
@@ -367,6 +368,9 @@  mlx5_vdpa_virtq_setup(struct mlx5_vdpa_priv *priv, int index)
 		goto error;
 	}
 	virtq->stopped = false;
+	/* Initial notification to ask qemu handling completed buffers. */
+	if (virtq->eqp.cq.callfd != -1)
+		eventfd_write(virtq->eqp.cq.callfd, (eventfd_t)1);
 	DRV_LOG(DEBUG, "vid %u virtq %u was created successfully.", priv->vid,
 		index);
 	return 0;