| Message ID | 20240327111430.108787-4-xuanzhuo@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | virtio: drivers maintain dma info for premapped vq | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply |
On Wed, Mar 27, 2024 at 7:14 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > This commit structure the indirect desc table. > Then we can get the desc num directly when doing unmap. > > And save the dma info to the struct, then the indirect > will not use the dma fields of the desc_extra. The subsequent > commits will make the dma fields are optional. Nit: It's better to add something like "so we can't reuse the desc_extra[] array" > But for > the indirect case, we must record the dma info. > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > drivers/virtio/virtio_ring.c | 61 +++++++++++++++++++----------------- > 1 file changed, 33 insertions(+), 28 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index a2838fe1cc08..e3343cf55774 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -74,7 +74,7 @@ struct vring_desc_state_split { > > struct vring_desc_state_packed { > void *data; /* Data for callback. */ > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > + struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ Should be "DMA info with indirect descriptor, if any" ? > u16 num; /* Descriptor list length. */ > u16 last; /* The last desc state in a list. */ > }; > @@ -1243,10 +1243,13 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, > DMA_FROM_DEVICE : DMA_TO_DEVICE); > } > > -static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > - gfp_t gfp) > +static struct vring_desc_extra *alloc_indirect_packed(unsigned int total_sg, > + gfp_t gfp) > { > - struct vring_packed_desc *desc; > + struct vring_desc_extra *in_extra; > + u32 size; > + > + size = sizeof(*in_extra) + sizeof(struct vring_packed_desc) * total_sg; > > /* > * We require lowmem mappings for the descriptors because > @@ -1255,9 +1258,10 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > */ > gfp &= ~__GFP_HIGHMEM; > > - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); > > - return desc; > + in_extra = kmalloc(size, gfp); > + > + return in_extra; > } > > static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > @@ -1268,6 +1272,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > void *data, > gfp_t gfp) > { > + struct vring_desc_extra *in_extra; > struct vring_packed_desc *desc; > struct scatterlist *sg; > unsigned int i, n, err_idx; > @@ -1275,10 +1280,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > dma_addr_t addr; > > head = vq->packed.next_avail_idx; > - desc = alloc_indirect_packed(total_sg, gfp); > - if (!desc) > + in_extra = alloc_indirect_packed(total_sg, gfp); > + if (!in_extra) > return -ENOMEM; > > + desc = (struct vring_packed_desc *)(in_extra + 1); > + > if (unlikely(vq->vq.num_free < 1)) { > pr_debug("Can't add buf len 1 - avail = 0\n"); > kfree(desc); > @@ -1315,17 +1322,16 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > goto unmap_release; > } > > + if (vq->use_dma_api) { > + in_extra->addr = addr; > + in_extra->len = total_sg * sizeof(struct vring_packed_desc); > + } Any reason why we don't do it after the below assignment of descriptor fields? > + > vq->packed.vring.desc[head].addr = cpu_to_le64(addr); > vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * > sizeof(struct vring_packed_desc)); > vq->packed.vring.desc[head].id = cpu_to_le16(id); > > - if (vq->use_dma_api) { > - vq->packed.desc_extra[id].addr = addr; > - vq->packed.desc_extra[id].len = total_sg * > - sizeof(struct vring_packed_desc); > - } > - > vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | > vq->packed.avail_used_flags; > > @@ -1356,7 +1362,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > /* Store token and indirect buffer state. */ > vq->packed.desc_state[id].num = 1; > vq->packed.desc_state[id].data = data; > - vq->packed.desc_state[id].indir_desc = desc; > + vq->packed.desc_state[id].indir_desc = in_extra; > vq->packed.desc_state[id].last = id; > > vq->num_added += 1; > @@ -1375,7 +1381,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > vring_unmap_desc_packed(vq, &desc[i]); > > free_desc: > - kfree(desc); > + kfree(in_extra); > > END_USE(vq); > return -ENOMEM; > @@ -1589,7 +1595,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > unsigned int id, void **ctx) > { > struct vring_desc_state_packed *state = NULL; > - struct vring_packed_desc *desc; > unsigned int i, curr; > u16 flags; > > @@ -1616,27 +1621,27 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > if (ctx) > *ctx = state->indir_desc; > } else { > - const struct vring_desc_extra *extra; > - u32 len; > + struct vring_desc_extra *in_extra; > + struct vring_packed_desc *desc; > + u32 num; > + > + in_extra = state->indir_desc; > > if (vq->use_dma_api) { > - extra = &vq->packed.desc_extra[id]; > dma_unmap_single(vring_dma_dev(vq), > - extra->addr, extra->len, > + in_extra->addr, in_extra->len, > (flags & VRING_DESC_F_WRITE) ? > DMA_FROM_DEVICE : DMA_TO_DEVICE); Can't we just reuse vring_unmap_extra_packed() here? Thanks > } > > - /* Free the indirect table, if any, now that it's unmapped. */ > - desc = state->indir_desc; > - > if (vring_need_unmap_buffer(vq)) { > - len = vq->packed.desc_extra[id].len; > - for (i = 0; i < len / sizeof(struct vring_packed_desc); > - i++) > + num = in_extra->len / sizeof(struct vring_packed_desc); > + desc = (struct vring_packed_desc *)(in_extra + 1); > + > + for (i = 0; i < num; i++) > vring_unmap_desc_packed(vq, &desc[i]); > } > - kfree(desc); > + kfree(in_extra); > state->indir_desc = NULL; > } > } > -- > 2.32.0.3.g01195cf9f >
On Thu, 28 Mar 2024 14:56:55 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Wed, Mar 27, 2024 at 7:14 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > This commit structure the indirect desc table. > > Then we can get the desc num directly when doing unmap. > > > > And save the dma info to the struct, then the indirect > > will not use the dma fields of the desc_extra. The subsequent > > commits will make the dma fields are optional. > > Nit: It's better to add something like "so we can't reuse the > desc_extra[] array" > > > But for > > the indirect case, we must record the dma info. > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > --- > > drivers/virtio/virtio_ring.c | 61 +++++++++++++++++++----------------- > > 1 file changed, 33 insertions(+), 28 deletions(-) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index a2838fe1cc08..e3343cf55774 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -74,7 +74,7 @@ struct vring_desc_state_split { > > > > struct vring_desc_state_packed { > > void *data; /* Data for callback. */ > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > + struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ > > Should be "DMA info with indirect descriptor, if any" ? > > > u16 num; /* Descriptor list length. */ > > u16 last; /* The last desc state in a list. */ > > }; > > @@ -1243,10 +1243,13 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, > > DMA_FROM_DEVICE : DMA_TO_DEVICE); > > } > > > > -static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > > - gfp_t gfp) > > +static struct vring_desc_extra *alloc_indirect_packed(unsigned int total_sg, > > + gfp_t gfp) > > { > > - struct vring_packed_desc *desc; > > + struct vring_desc_extra *in_extra; > > + u32 size; > > + > > + size = sizeof(*in_extra) + sizeof(struct vring_packed_desc) * total_sg; > > > > /* > > * We require lowmem mappings for the descriptors because > > @@ -1255,9 +1258,10 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > > */ > > gfp &= ~__GFP_HIGHMEM; > > > > - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); > > > > - return desc; > > + in_extra = kmalloc(size, gfp); > > + > > + return in_extra; > > } > > > > static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > @@ -1268,6 +1272,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > void *data, > > gfp_t gfp) > > { > > + struct vring_desc_extra *in_extra; > > struct vring_packed_desc *desc; > > struct scatterlist *sg; > > unsigned int i, n, err_idx; > > @@ -1275,10 +1280,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > dma_addr_t addr; > > > > head = vq->packed.next_avail_idx; > > - desc = alloc_indirect_packed(total_sg, gfp); > > - if (!desc) > > + in_extra = alloc_indirect_packed(total_sg, gfp); > > + if (!in_extra) > > return -ENOMEM; > > > > + desc = (struct vring_packed_desc *)(in_extra + 1); > > + > > if (unlikely(vq->vq.num_free < 1)) { > > pr_debug("Can't add buf len 1 - avail = 0\n"); > > kfree(desc); > > @@ -1315,17 +1322,16 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > goto unmap_release; > > } > > > > + if (vq->use_dma_api) { > > + in_extra->addr = addr; > > + in_extra->len = total_sg * sizeof(struct vring_packed_desc); > > + } > > Any reason why we don't do it after the below assignment of descriptor fields? > > > + > > vq->packed.vring.desc[head].addr = cpu_to_le64(addr); > > vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * > > sizeof(struct vring_packed_desc)); > > vq->packed.vring.desc[head].id = cpu_to_le16(id); > > > > - if (vq->use_dma_api) { > > - vq->packed.desc_extra[id].addr = addr; > > - vq->packed.desc_extra[id].len = total_sg * > > - sizeof(struct vring_packed_desc); > > - } > > - > > vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | > > vq->packed.avail_used_flags; > > > > @@ -1356,7 +1362,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > /* Store token and indirect buffer state. */ > > vq->packed.desc_state[id].num = 1; > > vq->packed.desc_state[id].data = data; > > - vq->packed.desc_state[id].indir_desc = desc; > > + vq->packed.desc_state[id].indir_desc = in_extra; > > vq->packed.desc_state[id].last = id; > > > > vq->num_added += 1; > > @@ -1375,7 +1381,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > vring_unmap_desc_packed(vq, &desc[i]); > > > > free_desc: > > - kfree(desc); > > + kfree(in_extra); > > > > END_USE(vq); > > return -ENOMEM; > > @@ -1589,7 +1595,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > > unsigned int id, void **ctx) > > { > > struct vring_desc_state_packed *state = NULL; > > - struct vring_packed_desc *desc; > > unsigned int i, curr; > > u16 flags; > > > > @@ -1616,27 +1621,27 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > > if (ctx) > > *ctx = state->indir_desc; > > } else { > > - const struct vring_desc_extra *extra; > > - u32 len; > > + struct vring_desc_extra *in_extra; > > + struct vring_packed_desc *desc; > > + u32 num; > > + > > + in_extra = state->indir_desc; > > > > if (vq->use_dma_api) { > > - extra = &vq->packed.desc_extra[id]; > > dma_unmap_single(vring_dma_dev(vq), > > - extra->addr, extra->len, > > + in_extra->addr, in_extra->len, > > (flags & VRING_DESC_F_WRITE) ? > > DMA_FROM_DEVICE : DMA_TO_DEVICE); > > Can't we just reuse vring_unmap_extra_packed() here? vring_unmap_extra_packed calls dma_unmap_page. Here needs dma_unmap_single. You mean we call dma_unmap_page directly. Thanks. > > Thanks > > > > } > > > > - /* Free the indirect table, if any, now that it's unmapped. */ > > - desc = state->indir_desc; > > - > > if (vring_need_unmap_buffer(vq)) { > > - len = vq->packed.desc_extra[id].len; > > - for (i = 0; i < len / sizeof(struct vring_packed_desc); > > - i++) > > + num = in_extra->len / sizeof(struct vring_packed_desc); > > + desc = (struct vring_packed_desc *)(in_extra + 1); > > + > > + for (i = 0; i < num; i++) > > vring_unmap_desc_packed(vq, &desc[i]); > > } > > - kfree(desc); > > + kfree(in_extra); > > state->indir_desc = NULL; > > } > > } > > -- > > 2.32.0.3.g01195cf9f > > >
On Thu, Mar 28, 2024 at 3:38 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > On Thu, 28 Mar 2024 14:56:55 +0800, Jason Wang <jasowang@redhat.com> wrote: > > On Wed, Mar 27, 2024 at 7:14 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > This commit structure the indirect desc table. > > > Then we can get the desc num directly when doing unmap. > > > > > > And save the dma info to the struct, then the indirect > > > will not use the dma fields of the desc_extra. The subsequent > > > commits will make the dma fields are optional. > > > > Nit: It's better to add something like "so we can't reuse the > > desc_extra[] array" > > > > > But for > > > the indirect case, we must record the dma info. > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > --- > > > drivers/virtio/virtio_ring.c | 61 +++++++++++++++++++----------------- > > > 1 file changed, 33 insertions(+), 28 deletions(-) > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > index a2838fe1cc08..e3343cf55774 100644 > > > --- a/drivers/virtio/virtio_ring.c > > > +++ b/drivers/virtio/virtio_ring.c > > > @@ -74,7 +74,7 @@ struct vring_desc_state_split { > > > > > > struct vring_desc_state_packed { > > > void *data; /* Data for callback. */ > > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > > + struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ > > > > Should be "DMA info with indirect descriptor, if any" ? > > > > > u16 num; /* Descriptor list length. */ > > > u16 last; /* The last desc state in a list. */ > > > }; > > > @@ -1243,10 +1243,13 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, > > > DMA_FROM_DEVICE : DMA_TO_DEVICE); > > > } > > > > > > -static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > > > - gfp_t gfp) > > > +static struct vring_desc_extra *alloc_indirect_packed(unsigned int total_sg, > > > + gfp_t gfp) > > > { > > > - struct vring_packed_desc *desc; > > > + struct vring_desc_extra *in_extra; > > > + u32 size; > > > + > > > + size = sizeof(*in_extra) + sizeof(struct vring_packed_desc) * total_sg; > > > > > > /* > > > * We require lowmem mappings for the descriptors because > > > @@ -1255,9 +1258,10 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > > > */ > > > gfp &= ~__GFP_HIGHMEM; > > > > > > - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); > > > > > > - return desc; > > > + in_extra = kmalloc(size, gfp); > > > + > > > + return in_extra; > > > } > > > > > > static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > @@ -1268,6 +1272,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > void *data, > > > gfp_t gfp) > > > { > > > + struct vring_desc_extra *in_extra; > > > struct vring_packed_desc *desc; > > > struct scatterlist *sg; > > > unsigned int i, n, err_idx; > > > @@ -1275,10 +1280,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > dma_addr_t addr; > > > > > > head = vq->packed.next_avail_idx; > > > - desc = alloc_indirect_packed(total_sg, gfp); > > > - if (!desc) > > > + in_extra = alloc_indirect_packed(total_sg, gfp); > > > + if (!in_extra) > > > return -ENOMEM; > > > > > > + desc = (struct vring_packed_desc *)(in_extra + 1); > > > + > > > if (unlikely(vq->vq.num_free < 1)) { > > > pr_debug("Can't add buf len 1 - avail = 0\n"); > > > kfree(desc); > > > @@ -1315,17 +1322,16 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > goto unmap_release; > > > } > > > > > > + if (vq->use_dma_api) { > > > + in_extra->addr = addr; > > > + in_extra->len = total_sg * sizeof(struct vring_packed_desc); > > > + } > > > > Any reason why we don't do it after the below assignment of descriptor fields? > > > > > + > > > vq->packed.vring.desc[head].addr = cpu_to_le64(addr); > > > vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * > > > sizeof(struct vring_packed_desc)); > > > vq->packed.vring.desc[head].id = cpu_to_le16(id); > > > > > > - if (vq->use_dma_api) { > > > - vq->packed.desc_extra[id].addr = addr; > > > - vq->packed.desc_extra[id].len = total_sg * > > > - sizeof(struct vring_packed_desc); > > > - } > > > - > > > vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | > > > vq->packed.avail_used_flags; > > > > > > @@ -1356,7 +1362,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > /* Store token and indirect buffer state. */ > > > vq->packed.desc_state[id].num = 1; > > > vq->packed.desc_state[id].data = data; > > > - vq->packed.desc_state[id].indir_desc = desc; > > > + vq->packed.desc_state[id].indir_desc = in_extra; > > > vq->packed.desc_state[id].last = id; > > > > > > vq->num_added += 1; > > > @@ -1375,7 +1381,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > vring_unmap_desc_packed(vq, &desc[i]); > > > > > > free_desc: > > > - kfree(desc); > > > + kfree(in_extra); > > > > > > END_USE(vq); > > > return -ENOMEM; > > > @@ -1589,7 +1595,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > > > unsigned int id, void **ctx) > > > { > > > struct vring_desc_state_packed *state = NULL; > > > - struct vring_packed_desc *desc; > > > unsigned int i, curr; > > > u16 flags; > > > > > > @@ -1616,27 +1621,27 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > > > if (ctx) > > > *ctx = state->indir_desc; > > > } else { > > > - const struct vring_desc_extra *extra; > > > - u32 len; > > > + struct vring_desc_extra *in_extra; > > > + struct vring_packed_desc *desc; > > > + u32 num; > > > + > > > + in_extra = state->indir_desc; > > > > > > if (vq->use_dma_api) { > > > - extra = &vq->packed.desc_extra[id]; > > > dma_unmap_single(vring_dma_dev(vq), > > > - extra->addr, extra->len, > > > + in_extra->addr, in_extra->len, > > > (flags & VRING_DESC_F_WRITE) ? > > > DMA_FROM_DEVICE : DMA_TO_DEVICE); > > > > Can't we just reuse vring_unmap_extra_packed() here? > > vring_unmap_extra_packed calls dma_unmap_page. > Here needs dma_unmap_single. > > You mean we call dma_unmap_page directly. Nope, I meant having a helper for this. Thanks > > Thanks. > > > > > Thanks > > > > > > > } > > > > > > - /* Free the indirect table, if any, now that it's unmapped. */ > > > - desc = state->indir_desc; > > > - > > > if (vring_need_unmap_buffer(vq)) { > > > - len = vq->packed.desc_extra[id].len; > > > - for (i = 0; i < len / sizeof(struct vring_packed_desc); > > > - i++) > > > + num = in_extra->len / sizeof(struct vring_packed_desc); > > > + desc = (struct vring_packed_desc *)(in_extra + 1); > > > + > > > + for (i = 0; i < num; i++) > > > vring_unmap_desc_packed(vq, &desc[i]); > > > } > > > - kfree(desc); > > > + kfree(in_extra); > > > state->indir_desc = NULL; > > > } > > > } > > > -- > > > 2.32.0.3.g01195cf9f > > > > > >
On Thu, 28 Mar 2024 16:07:03 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Thu, Mar 28, 2024 at 3:38 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > On Thu, 28 Mar 2024 14:56:55 +0800, Jason Wang <jasowang@redhat.com> wrote: > > > On Wed, Mar 27, 2024 at 7:14 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > > > This commit structure the indirect desc table. > > > > Then we can get the desc num directly when doing unmap. > > > > > > > > And save the dma info to the struct, then the indirect > > > > will not use the dma fields of the desc_extra. The subsequent > > > > commits will make the dma fields are optional. > > > > > > Nit: It's better to add something like "so we can't reuse the > > > desc_extra[] array" > > > > > > > But for > > > > the indirect case, we must record the dma info. > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > > --- > > > > drivers/virtio/virtio_ring.c | 61 +++++++++++++++++++----------------- > > > > 1 file changed, 33 insertions(+), 28 deletions(-) > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > index a2838fe1cc08..e3343cf55774 100644 > > > > --- a/drivers/virtio/virtio_ring.c > > > > +++ b/drivers/virtio/virtio_ring.c > > > > @@ -74,7 +74,7 @@ struct vring_desc_state_split { > > > > > > > > struct vring_desc_state_packed { > > > > void *data; /* Data for callback. */ > > > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > + struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ > > > > > > Should be "DMA info with indirect descriptor, if any" ? > > > > > > > u16 num; /* Descriptor list length. */ > > > > u16 last; /* The last desc state in a list. */ > > > > }; > > > > @@ -1243,10 +1243,13 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, > > > > DMA_FROM_DEVICE : DMA_TO_DEVICE); > > > > } > > > > > > > > -static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > > > > - gfp_t gfp) > > > > +static struct vring_desc_extra *alloc_indirect_packed(unsigned int total_sg, > > > > + gfp_t gfp) > > > > { > > > > - struct vring_packed_desc *desc; > > > > + struct vring_desc_extra *in_extra; > > > > + u32 size; > > > > + > > > > + size = sizeof(*in_extra) + sizeof(struct vring_packed_desc) * total_sg; > > > > > > > > /* > > > > * We require lowmem mappings for the descriptors because > > > > @@ -1255,9 +1258,10 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, > > > > */ > > > > gfp &= ~__GFP_HIGHMEM; > > > > > > > > - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); > > > > > > > > - return desc; > > > > + in_extra = kmalloc(size, gfp); > > > > + > > > > + return in_extra; > > > > } > > > > > > > > static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > > @@ -1268,6 +1272,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > > void *data, > > > > gfp_t gfp) > > > > { > > > > + struct vring_desc_extra *in_extra; > > > > struct vring_packed_desc *desc; > > > > struct scatterlist *sg; > > > > unsigned int i, n, err_idx; > > > > @@ -1275,10 +1280,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > > dma_addr_t addr; > > > > > > > > head = vq->packed.next_avail_idx; > > > > - desc = alloc_indirect_packed(total_sg, gfp); > > > > - if (!desc) > > > > + in_extra = alloc_indirect_packed(total_sg, gfp); > > > > + if (!in_extra) > > > > return -ENOMEM; > > > > > > > > + desc = (struct vring_packed_desc *)(in_extra + 1); > > > > + > > > > if (unlikely(vq->vq.num_free < 1)) { > > > > pr_debug("Can't add buf len 1 - avail = 0\n"); > > > > kfree(desc); > > > > @@ -1315,17 +1322,16 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > > goto unmap_release; > > > > } > > > > > > > > + if (vq->use_dma_api) { > > > > + in_extra->addr = addr; > > > > + in_extra->len = total_sg * sizeof(struct vring_packed_desc); > > > > + } > > > > > > Any reason why we don't do it after the below assignment of descriptor fields? > > > > > > > + > > > > vq->packed.vring.desc[head].addr = cpu_to_le64(addr); > > > > vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * > > > > sizeof(struct vring_packed_desc)); > > > > vq->packed.vring.desc[head].id = cpu_to_le16(id); > > > > > > > > - if (vq->use_dma_api) { > > > > - vq->packed.desc_extra[id].addr = addr; > > > > - vq->packed.desc_extra[id].len = total_sg * > > > > - sizeof(struct vring_packed_desc); > > > > - } > > > > - > > > > vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | > > > > vq->packed.avail_used_flags; > > > > > > > > @@ -1356,7 +1362,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > > /* Store token and indirect buffer state. */ > > > > vq->packed.desc_state[id].num = 1; > > > > vq->packed.desc_state[id].data = data; > > > > - vq->packed.desc_state[id].indir_desc = desc; > > > > + vq->packed.desc_state[id].indir_desc = in_extra; > > > > vq->packed.desc_state[id].last = id; > > > > > > > > vq->num_added += 1; > > > > @@ -1375,7 +1381,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, > > > > vring_unmap_desc_packed(vq, &desc[i]); > > > > > > > > free_desc: > > > > - kfree(desc); > > > > + kfree(in_extra); > > > > > > > > END_USE(vq); > > > > return -ENOMEM; > > > > @@ -1589,7 +1595,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > > > > unsigned int id, void **ctx) > > > > { > > > > struct vring_desc_state_packed *state = NULL; > > > > - struct vring_packed_desc *desc; > > > > unsigned int i, curr; > > > > u16 flags; > > > > > > > > @@ -1616,27 +1621,27 @@ static void detach_buf_packed(struct vring_virtqueue *vq, > > > > if (ctx) > > > > *ctx = state->indir_desc; > > > > } else { > > > > - const struct vring_desc_extra *extra; > > > > - u32 len; > > > > + struct vring_desc_extra *in_extra; > > > > + struct vring_packed_desc *desc; > > > > + u32 num; > > > > + > > > > + in_extra = state->indir_desc; > > > > > > > > if (vq->use_dma_api) { > > > > - extra = &vq->packed.desc_extra[id]; > > > > dma_unmap_single(vring_dma_dev(vq), > > > > - extra->addr, extra->len, > > > > + in_extra->addr, in_extra->len, > > > > (flags & VRING_DESC_F_WRITE) ? > > > > DMA_FROM_DEVICE : DMA_TO_DEVICE); > > > > > > Can't we just reuse vring_unmap_extra_packed() here? > > > > vring_unmap_extra_packed calls dma_unmap_page. > > Here needs dma_unmap_single. > > > > You mean we call dma_unmap_page directly. > > Nope, I meant having a helper for this. OK. I will add a helper. Thanks. > > Thanks > > > > > > Thanks. > > > > > > > > Thanks > > > > > > > > > > } > > > > > > > > - /* Free the indirect table, if any, now that it's unmapped. */ > > > > - desc = state->indir_desc; > > > > - > > > > if (vring_need_unmap_buffer(vq)) { > > > > - len = vq->packed.desc_extra[id].len; > > > > - for (i = 0; i < len / sizeof(struct vring_packed_desc); > > > > - i++) > > > > + num = in_extra->len / sizeof(struct vring_packed_desc); > > > > + desc = (struct vring_packed_desc *)(in_extra + 1); > > > > + > > > > + for (i = 0; i < num; i++) > > > > vring_unmap_desc_packed(vq, &desc[i]); > > > > } > > > > - kfree(desc); > > > > + kfree(in_extra); > > > > state->indir_desc = NULL; > > > > } > > > > } > > > > -- > > > > 2.32.0.3.g01195cf9f > > > > > > > > > >
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a2838fe1cc08..e3343cf55774 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -74,7 +74,7 @@ struct vring_desc_state_split { struct vring_desc_state_packed { void *data; /* Data for callback. */ - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ + struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ }; @@ -1243,10 +1243,13 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, DMA_FROM_DEVICE : DMA_TO_DEVICE); } -static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, - gfp_t gfp) +static struct vring_desc_extra *alloc_indirect_packed(unsigned int total_sg, + gfp_t gfp) { - struct vring_packed_desc *desc; + struct vring_desc_extra *in_extra; + u32 size; + + size = sizeof(*in_extra) + sizeof(struct vring_packed_desc) * total_sg; /* * We require lowmem mappings for the descriptors because @@ -1255,9 +1258,10 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, */ gfp &= ~__GFP_HIGHMEM; - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); - return desc; + in_extra = kmalloc(size, gfp); + + return in_extra; } static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, @@ -1268,6 +1272,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, void *data, gfp_t gfp) { + struct vring_desc_extra *in_extra; struct vring_packed_desc *desc; struct scatterlist *sg; unsigned int i, n, err_idx; @@ -1275,10 +1280,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, dma_addr_t addr; head = vq->packed.next_avail_idx; - desc = alloc_indirect_packed(total_sg, gfp); - if (!desc) + in_extra = alloc_indirect_packed(total_sg, gfp); + if (!in_extra) return -ENOMEM; + desc = (struct vring_packed_desc *)(in_extra + 1); + if (unlikely(vq->vq.num_free < 1)) { pr_debug("Can't add buf len 1 - avail = 0\n"); kfree(desc); @@ -1315,17 +1322,16 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, goto unmap_release; } + if (vq->use_dma_api) { + in_extra->addr = addr; + in_extra->len = total_sg * sizeof(struct vring_packed_desc); + } + vq->packed.vring.desc[head].addr = cpu_to_le64(addr); vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * sizeof(struct vring_packed_desc)); vq->packed.vring.desc[head].id = cpu_to_le16(id); - if (vq->use_dma_api) { - vq->packed.desc_extra[id].addr = addr; - vq->packed.desc_extra[id].len = total_sg * - sizeof(struct vring_packed_desc); - } - vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | vq->packed.avail_used_flags; @@ -1356,7 +1362,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, /* Store token and indirect buffer state. */ vq->packed.desc_state[id].num = 1; vq->packed.desc_state[id].data = data; - vq->packed.desc_state[id].indir_desc = desc; + vq->packed.desc_state[id].indir_desc = in_extra; vq->packed.desc_state[id].last = id; vq->num_added += 1; @@ -1375,7 +1381,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, vring_unmap_desc_packed(vq, &desc[i]); free_desc: - kfree(desc); + kfree(in_extra); END_USE(vq); return -ENOMEM; @@ -1589,7 +1595,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq, unsigned int id, void **ctx) { struct vring_desc_state_packed *state = NULL; - struct vring_packed_desc *desc; unsigned int i, curr; u16 flags; @@ -1616,27 +1621,27 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (ctx) *ctx = state->indir_desc; } else { - const struct vring_desc_extra *extra; - u32 len; + struct vring_desc_extra *in_extra; + struct vring_packed_desc *desc; + u32 num; + + in_extra = state->indir_desc; if (vq->use_dma_api) { - extra = &vq->packed.desc_extra[id]; dma_unmap_single(vring_dma_dev(vq), - extra->addr, extra->len, + in_extra->addr, in_extra->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } - /* Free the indirect table, if any, now that it's unmapped. */ - desc = state->indir_desc; - if (vring_need_unmap_buffer(vq)) { - len = vq->packed.desc_extra[id].len; - for (i = 0; i < len / sizeof(struct vring_packed_desc); - i++) + num = in_extra->len / sizeof(struct vring_packed_desc); + desc = (struct vring_packed_desc *)(in_extra + 1); + + for (i = 0; i < num; i++) vring_unmap_desc_packed(vq, &desc[i]); } - kfree(desc); + kfree(in_extra); state->indir_desc = NULL; } }
This commit structure the indirect desc table. Then we can get the desc num directly when doing unmap. And save the dma info to the struct, then the indirect will not use the dma fields of the desc_extra. The subsequent commits will make the dma fields are optional. But for the indirect case, we must record the dma info. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 61 +++++++++++++++++++----------------- 1 file changed, 33 insertions(+), 28 deletions(-)