diff mbox series

vdpa/mlx5: Fix memory key MTT population

Message ID 20210106090557.GA170338@mtl-vdi-166.wap.labs.mlnx (mailing list archive)
State Superseded
Headers show
Series vdpa/mlx5: Fix memory key MTT population | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Eli Cohen Jan. 6, 2021, 9:05 a.m. UTC
map_direct_mr() assumed that the number of scatter/gather entries
returned by dma_map_sg_attrs() was equal to the number of segments in
the sgl list. This led to wrong population of the mkey object. Fix this
by properly referring to the returned value.

In addition, get rid of fill_sg() whjich effect is overwritten bu
populate_mtts().

Fixes: 94abbccdf291 ("vdpa/mlx5: Add shared memory registration code")
Signed-off-by: Eli Cohen <elic@nvidia.com>
---
 drivers/vdpa/mlx5/core/mlx5_vdpa.h |  1 +
 drivers/vdpa/mlx5/core/mr.c        | 28 ++++++++++++----------------
 2 files changed, 13 insertions(+), 16 deletions(-)

Comments

Jason Wang Jan. 7, 2021, 4:15 a.m. UTC | #1
On 2021/1/6 下午5:05, Eli Cohen wrote:
> map_direct_mr() assumed that the number of scatter/gather entries
> returned by dma_map_sg_attrs() was equal to the number of segments in
> the sgl list. This led to wrong population of the mkey object. Fix this
> by properly referring to the returned value.
>
> In addition, get rid of fill_sg() whjich effect is overwritten bu
> populate_mtts().


Typo.


>
> Fixes: 94abbccdf291 ("vdpa/mlx5: Add shared memory registration code")
> Signed-off-by: Eli Cohen <elic@nvidia.com>
> ---
>   drivers/vdpa/mlx5/core/mlx5_vdpa.h |  1 +
>   drivers/vdpa/mlx5/core/mr.c        | 28 ++++++++++++----------------
>   2 files changed, 13 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> index 5c92a576edae..08f742fd2409 100644
> --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> @@ -15,6 +15,7 @@ struct mlx5_vdpa_direct_mr {
>   	struct sg_table sg_head;
>   	int log_size;
>   	int nsg;
> +	int nent;
>   	struct list_head list;
>   	u64 offset;
>   };
> diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> index 4b6195666c58..d300f799efcd 100644
> --- a/drivers/vdpa/mlx5/core/mr.c
> +++ b/drivers/vdpa/mlx5/core/mr.c
> @@ -25,17 +25,6 @@ static int get_octo_len(u64 len, int page_shift)
>   	return (npages + 1) / 2;
>   }
>   
> -static void fill_sg(struct mlx5_vdpa_direct_mr *mr, void *in)
> -{
> -	struct scatterlist *sg;
> -	__be64 *pas;
> -	int i;
> -
> -	pas = MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt);
> -	for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i)
> -		(*pas) = cpu_to_be64(sg_dma_address(sg));
> -}
> -
>   static void mlx5_set_access_mode(void *mkc, int mode)
>   {
>   	MLX5_SET(mkc, mkc, access_mode_1_0, mode & 0x3);
> @@ -45,10 +34,18 @@ static void mlx5_set_access_mode(void *mkc, int mode)
>   static void populate_mtts(struct mlx5_vdpa_direct_mr *mr, __be64 *mtt)
>   {
>   	struct scatterlist *sg;
> +	int nsg = mr->nsg;
> +	u64 dma_addr;
> +	u64 dma_len;
> +	int j = 0;
>   	int i;
>   
> -	for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i)
> -		mtt[i] = cpu_to_be64(sg_dma_address(sg));
> +	for_each_sg(mr->sg_head.sgl, sg, mr->nent, i) {
> +		for (dma_addr = sg_dma_address(sg), dma_len = sg_dma_len(sg);
> +		     nsg && dma_len;
> +		     nsg--, dma_addr += BIT(mr->log_size), dma_len -= BIT(mr->log_size))
> +			mtt[j++] = cpu_to_be64(dma_addr);


It looks to me the mtt entry is also limited by log_size. It's better to 
explain this a little bit in the commit log.

Thanks


> +	}
>   }
>   
>   static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr)
> @@ -64,7 +61,6 @@ static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct
>   		return -ENOMEM;
>   
>   	MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
> -	fill_sg(mr, in);
>   	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
>   	MLX5_SET(mkc, mkc, lw, !!(mr->perm & VHOST_MAP_WO));
>   	MLX5_SET(mkc, mkc, lr, !!(mr->perm & VHOST_MAP_RO));
> @@ -276,8 +272,8 @@ static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
>   done:
>   	mr->log_size = log_entity_size;
>   	mr->nsg = nsg;
> -	err = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
> -	if (!err)
> +	mr->nent = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
> +	if (!mr->nent)
>   		goto err_map;
>   
>   	err = create_direct_mr(mvdev, mr);
Eli Cohen Jan. 7, 2021, 6:07 a.m. UTC | #2
On Thu, Jan 07, 2021 at 12:15:53PM +0800, Jason Wang wrote:
> 
> On 2021/1/6 下午5:05, Eli Cohen wrote:
> > map_direct_mr() assumed that the number of scatter/gather entries
> > returned by dma_map_sg_attrs() was equal to the number of segments in
> > the sgl list. This led to wrong population of the mkey object. Fix this
> > by properly referring to the returned value.
> > 
> > In addition, get rid of fill_sg() whjich effect is overwritten bu
> > populate_mtts().
> 
> 
> Typo.
> 
Will fix, thanks.
> 
> > 
> > Fixes: 94abbccdf291 ("vdpa/mlx5: Add shared memory registration code")
> > Signed-off-by: Eli Cohen <elic@nvidia.com>
> > ---
> >   drivers/vdpa/mlx5/core/mlx5_vdpa.h |  1 +
> >   drivers/vdpa/mlx5/core/mr.c        | 28 ++++++++++++----------------
> >   2 files changed, 13 insertions(+), 16 deletions(-)
> > 
> > diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> > index 5c92a576edae..08f742fd2409 100644
> > --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> > +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> > @@ -15,6 +15,7 @@ struct mlx5_vdpa_direct_mr {
> >   	struct sg_table sg_head;
> >   	int log_size;
> >   	int nsg;
> > +	int nent;
> >   	struct list_head list;
> >   	u64 offset;
> >   };
> > diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> > index 4b6195666c58..d300f799efcd 100644
> > --- a/drivers/vdpa/mlx5/core/mr.c
> > +++ b/drivers/vdpa/mlx5/core/mr.c
> > @@ -25,17 +25,6 @@ static int get_octo_len(u64 len, int page_shift)
> >   	return (npages + 1) / 2;
> >   }
> > -static void fill_sg(struct mlx5_vdpa_direct_mr *mr, void *in)
> > -{
> > -	struct scatterlist *sg;
> > -	__be64 *pas;
> > -	int i;
> > -
> > -	pas = MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt);
> > -	for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i)
> > -		(*pas) = cpu_to_be64(sg_dma_address(sg));
> > -}
> > -
> >   static void mlx5_set_access_mode(void *mkc, int mode)
> >   {
> >   	MLX5_SET(mkc, mkc, access_mode_1_0, mode & 0x3);
> > @@ -45,10 +34,18 @@ static void mlx5_set_access_mode(void *mkc, int mode)
> >   static void populate_mtts(struct mlx5_vdpa_direct_mr *mr, __be64 *mtt)
> >   {
> >   	struct scatterlist *sg;
> > +	int nsg = mr->nsg;
> > +	u64 dma_addr;
> > +	u64 dma_len;
> > +	int j = 0;
> >   	int i;
> > -	for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i)
> > -		mtt[i] = cpu_to_be64(sg_dma_address(sg));
> > +	for_each_sg(mr->sg_head.sgl, sg, mr->nent, i) {
> > +		for (dma_addr = sg_dma_address(sg), dma_len = sg_dma_len(sg);
> > +		     nsg && dma_len;
> > +		     nsg--, dma_addr += BIT(mr->log_size), dma_len -= BIT(mr->log_size))
> > +			mtt[j++] = cpu_to_be64(dma_addr);
> 
> 
> It looks to me the mtt entry is also limited by log_size. It's better to
> explain this a little bit in the commit log.

Actually, each MTT entry covers (1 << mr->log_size) contiguous memory.
I will add an explanation.

> 
> Thanks
> 
> 
> > +	}
> >   }
> >   static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr)
> > @@ -64,7 +61,6 @@ static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct
> >   		return -ENOMEM;
> >   	MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
> > -	fill_sg(mr, in);
> >   	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
> >   	MLX5_SET(mkc, mkc, lw, !!(mr->perm & VHOST_MAP_WO));
> >   	MLX5_SET(mkc, mkc, lr, !!(mr->perm & VHOST_MAP_RO));
> > @@ -276,8 +272,8 @@ static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
> >   done:
> >   	mr->log_size = log_entity_size;
> >   	mr->nsg = nsg;
> > -	err = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
> > -	if (!err)
> > +	mr->nent = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
> > +	if (!mr->nent)
> >   		goto err_map;
> >   	err = create_direct_mr(mvdev, mr);
>
diff mbox series

Patch

diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
index 5c92a576edae..08f742fd2409 100644
--- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
+++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
@@ -15,6 +15,7 @@  struct mlx5_vdpa_direct_mr {
 	struct sg_table sg_head;
 	int log_size;
 	int nsg;
+	int nent;
 	struct list_head list;
 	u64 offset;
 };
diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index 4b6195666c58..d300f799efcd 100644
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -25,17 +25,6 @@  static int get_octo_len(u64 len, int page_shift)
 	return (npages + 1) / 2;
 }
 
-static void fill_sg(struct mlx5_vdpa_direct_mr *mr, void *in)
-{
-	struct scatterlist *sg;
-	__be64 *pas;
-	int i;
-
-	pas = MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt);
-	for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i)
-		(*pas) = cpu_to_be64(sg_dma_address(sg));
-}
-
 static void mlx5_set_access_mode(void *mkc, int mode)
 {
 	MLX5_SET(mkc, mkc, access_mode_1_0, mode & 0x3);
@@ -45,10 +34,18 @@  static void mlx5_set_access_mode(void *mkc, int mode)
 static void populate_mtts(struct mlx5_vdpa_direct_mr *mr, __be64 *mtt)
 {
 	struct scatterlist *sg;
+	int nsg = mr->nsg;
+	u64 dma_addr;
+	u64 dma_len;
+	int j = 0;
 	int i;
 
-	for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i)
-		mtt[i] = cpu_to_be64(sg_dma_address(sg));
+	for_each_sg(mr->sg_head.sgl, sg, mr->nent, i) {
+		for (dma_addr = sg_dma_address(sg), dma_len = sg_dma_len(sg);
+		     nsg && dma_len;
+		     nsg--, dma_addr += BIT(mr->log_size), dma_len -= BIT(mr->log_size))
+			mtt[j++] = cpu_to_be64(dma_addr);
+	}
 }
 
 static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr)
@@ -64,7 +61,6 @@  static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct
 		return -ENOMEM;
 
 	MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
-	fill_sg(mr, in);
 	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
 	MLX5_SET(mkc, mkc, lw, !!(mr->perm & VHOST_MAP_WO));
 	MLX5_SET(mkc, mkc, lr, !!(mr->perm & VHOST_MAP_RO));
@@ -276,8 +272,8 @@  static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
 done:
 	mr->log_size = log_entity_size;
 	mr->nsg = nsg;
-	err = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
-	if (!err)
+	mr->nent = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
+	if (!mr->nent)
 		goto err_map;
 
 	err = create_direct_mr(mvdev, mr);