Regular memory region changes already reset cvq iotlb at set_map.
However this is not true if CVQ and data VQs are in different ASID.

Clean the CVQ iotlb every time we hit dup_iotlb.

Fixes: 8fcd20c30704 ("vdpa/mlx5: Support different address spaces for control and data")
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 drivers/vdpa/mlx5/core/mr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index 0a1e0b0dc37e..ae34dcac9a3f 100644
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -456,6 +456,8 @@ static int dup_iotlb(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *src)
 	u64 start = 0, last = ULLONG_MAX;
 	int err;
 
+	vhost_iotlb_reset(mvdev->cvq.iotlb);
+
 	if (!src) {
 		err = vhost_iotlb_add_range(mvdev->cvq.iotlb, start, last, start, VHOST_ACCESS_RW);
 		return err;
-- 
2.31.1

> From: Eugenio Pérez <eperezma@redhat.com>
> Sent: Thursday, 12 January 2023 16:22
> To: mst@redhat.com; Eli Cohen <elic@nvidia.com>
> Cc: linux-kernel@vger.kernel.org; Parav Pandit <parav@nvidia.com>;
> lulu@redhat.com; jasowang@redhat.com; virtualization@lists.linux-
> foundation.org; sgarzare@redhat.com; si-wei.liu@oracle.com
> Subject: [RFC 1/3] vdpa/mlx5: reset iotlb at dup_iotlb
> 
> Regular memory region changes already reset cvq iotlb at set_map.
> However this is not true if CVQ and data VQs are in different ASID.
> 
> Clean the CVQ iotlb every time we hit dup_iotlb.
> 
> Fixes: 8fcd20c30704 ("vdpa/mlx5: Support different address spaces for
> control and data")
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>  drivers/vdpa/mlx5/core/mr.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> index 0a1e0b0dc37e..ae34dcac9a3f 100644
> --- a/drivers/vdpa/mlx5/core/mr.c
> +++ b/drivers/vdpa/mlx5/core/mr.c
> @@ -456,6 +456,8 @@ static int dup_iotlb(struct mlx5_vdpa_dev *mvdev,
> struct vhost_iotlb *src)
>  	u64 start = 0, last = ULLONG_MAX;
>  	int err;
> 
> +	vhost_iotlb_reset(mvdev->cvq.iotlb);
> +

As far as I can see, mlx5_vdpa_destroy_mr() is called independently of the asid
and it will calls prune_iotlb() which resets the cvq iotlb. Am I missing something?

>  	if (!src) {
>  		err = vhost_iotlb_add_range(mvdev->cvq.iotlb, start, last,
> start, VHOST_ACCESS_RW);
>  		return err;
> --
> 2.31.1

On Mon, Jan 16, 2023 at 7:32 AM Eli Cohen <elic@nvidia.com> wrote:
>
> > From: Eugenio Pérez <eperezma@redhat.com>
> > Sent: Thursday, 12 January 2023 16:22
> > To: mst@redhat.com; Eli Cohen <elic@nvidia.com>
> > Cc: linux-kernel@vger.kernel.org; Parav Pandit <parav@nvidia.com>;
> > lulu@redhat.com; jasowang@redhat.com; virtualization@lists.linux-
> > foundation.org; sgarzare@redhat.com; si-wei.liu@oracle.com
> > Subject: [RFC 1/3] vdpa/mlx5: reset iotlb at dup_iotlb
> >
> > Regular memory region changes already reset cvq iotlb at set_map.
> > However this is not true if CVQ and data VQs are in different ASID.
> >
> > Clean the CVQ iotlb every time we hit dup_iotlb.
> >
> > Fixes: 8fcd20c30704 ("vdpa/mlx5: Support different address spaces for
> > control and data")
> > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > ---
> >  drivers/vdpa/mlx5/core/mr.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> > index 0a1e0b0dc37e..ae34dcac9a3f 100644
> > --- a/drivers/vdpa/mlx5/core/mr.c
> > +++ b/drivers/vdpa/mlx5/core/mr.c
> > @@ -456,6 +456,8 @@ static int dup_iotlb(struct mlx5_vdpa_dev *mvdev,
> > struct vhost_iotlb *src)
> >       u64 start = 0, last = ULLONG_MAX;
> >       int err;
> >
> > +     vhost_iotlb_reset(mvdev->cvq.iotlb);
> > +
>
> As far as I can see, mlx5_vdpa_destroy_mr() is called independently of the asid
> and it will calls prune_iotlb() which resets the cvq iotlb. Am I missing something?
>

Sorry, my fault. It is not obvious from the patch but this prepares the code for
the next patch in the series.

With the next patch applied, prune_iotlb is not called in all
contexts. This patch may be dropped in future series.

Thanks!


> >       if (!src) {
> >               err = vhost_iotlb_add_range(mvdev->cvq.iotlb, start, last,
> > start, VHOST_ACCESS_RW);
> >               return err;
> > --
> > 2.31.1
>