Messages in this thread | | | Subject | Re: [PATCH v1] vdpa/mlx5: Fix memory key MTT population | From | Jason Wang <> | Date | Fri, 8 Jan 2021 16:38:55 +0800 |
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On 2021/1/7 下午3:18, 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. > > The hardware expects each MTT entry to contain the DMA address of a > contiguous block of memory of size (1 << mr->log_size) bytes. > dma_map_sg_attrs() can coalesce several sg entries into a single > scatter/gather entry of contiguous DMA range so we need to scan the list > and refer to the size of each s/g entry. > > In addition, get rid of fill_sg() which effect is overwritten by > populate_mtts(). > > Fixes: 94abbccdf291 ("vdpa/mlx5: Add shared memory registration code") > Signed-off-by: Eli Cohen <elic@nvidia.com> > --- > V0->V1: > 1. Fix typos > 2. Improve changelog
Acked-by: Jason Wang <jasowang@redhat.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); > + } > } > > 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);
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