Michael S. Tsirkin
2021-Jan-20 07:57 UTC
[PATCH v1] vdpa/mlx5: Fix memory key MTT population
On Wed, Jan 20, 2021 at 07:36:19AM +0200, Eli Cohen wrote:> On Fri, Jan 08, 2021 at 04:38:55PM +0800, Jason Wang wrote: > > Hi Michael, > this patch is a fix. Are you going to merge it?yes - in the next pull request.> > > > On 2021/1/7 ??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 at nvidia.com> > > > --- > > > V0->V1: > > > 1. Fix typos > > > 2. Improve changelog > > > > > > Acked-by: Jason Wang <jasowang at 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); > >