introduce virtqueue_get_buf_ctx_dma() to collect the dma info when get buf from virtio core for premapped mode.
If the virtio queue is premapped mode, the virtio-net send buf may have many desc. Every desc dma address need to be unmap. So here we introduce a new helper to collect the dma address of the buffer from the virtio core. Signed-off-by: Xuan Zhuo <[email protected]> --- drivers/virtio/virtio_ring.c | 157 +++++++++++++++++++++++------------ include/linux/virtio.h | 16 ++++ 2 files changed, 121 insertions(+), 52 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 51d8f3299c10..103d181f05bb 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -362,6 +362,26 @@ static struct device *vring_dma_dev(const struct vring_virtqueue *vq) return vq->dma_dev; } +static void collect_dma_info(const struct vring_virtqueue *vq, + struct virtio_dma_head *dma, + dma_addr_t addr, unsigned int length) +{ + if (WARN_ON_ONCE(!dma)) + return; + + if (unlikely(dma->next >= dma->num)) { + dev_warn_once(&vq->vq.vdev->dev, + "premapped vq: collect dma miss: %pad %u\n", + &addr, length); + return; + } + + dma->items[dma->next].addr = addr; + dma->items[dma->next].length = length; + + ++dma->next; +} + /* Map one sg entry. */ static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist *sg, enum dma_data_direction direction, dma_addr_t *addr) @@ -441,12 +461,17 @@ static void virtqueue_init(struct vring_virtqueue *vq, u32 num) */ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, - const struct vring_desc *desc) + const struct vring_desc *desc, + struct virtio_dma_head *dma) { u16 flags; - if (!vq->do_unmap) + if (!vq->do_unmap) { + collect_dma_info(vq, dma, + virtio64_to_cpu(vq->vq.vdev, desc->addr), + virtio32_to_cpu(vq->vq.vdev, desc->len)); return; + } flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); @@ -458,7 +483,7 @@ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, } static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, - unsigned int i) + unsigned int i, struct virtio_dma_head *dma) { struct vring_desc_extra *extra = vq->split.desc_extra; u16 flags; @@ -466,18 +491,15 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, flags = extra[i].flags; if (flags & VRING_DESC_F_INDIRECT) { - if (!vq->use_dma_api) - goto out; - - dma_unmap_single(vring_dma_dev(vq), - extra[i].addr, - extra[i].len, - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + if (vq->use_dma_api) + dma_unmap_single(vring_dma_dev(vq), + extra[i].addr, + extra[i].len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE); + } else if (!vq->do_unmap) { + collect_dma_info(vq, dma, extra[i].addr, extra[i].len); } else { - if (!vq->do_unmap) - goto out; - dma_unmap_page(vring_dma_dev(vq), extra[i].addr, extra[i].len, @@ -485,7 +507,6 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, DMA_FROM_DEVICE : DMA_TO_DEVICE); } -out: return extra[i].next; } @@ -717,10 +738,10 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, if (i == err_idx) break; if (indirect) { - vring_unmap_one_split_indirect(vq, &desc[i]); + vring_unmap_one_split_indirect(vq, &desc[i], NULL); i = virtio16_to_cpu(_vq->vdev, desc[i].next); } else - i = vring_unmap_one_split(vq, i); + i = vring_unmap_one_split(vq, i, NULL); } free_indirect: @@ -763,7 +784,7 @@ static bool virtqueue_kick_prepare_split(struct virtqueue *_vq) } static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, - void **ctx) + struct virtio_dma_head *dma, void **ctx) { unsigned int i, j; __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT); @@ -775,12 +796,12 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, i = head; while (vq->split.vring.desc[i].flags & nextflag) { - vring_unmap_one_split(vq, i); + vring_unmap_one_split(vq, i, dma); i = vq->split.desc_extra[i].next; vq->vq.num_free++; } - vring_unmap_one_split(vq, i); + vring_unmap_one_split(vq, i, dma); vq->split.desc_extra[i].next = vq->free_head; vq->free_head = head; @@ -802,10 +823,8 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, VRING_DESC_F_INDIRECT)); BUG_ON(len == 0 || len % sizeof(struct vring_desc)); - if (vq->do_unmap) { - for (j = 0; j < len / sizeof(struct vring_desc); j++) - vring_unmap_one_split_indirect(vq, &indir_desc[j]); - } + for (j = 0; j < len / sizeof(struct vring_desc); j++) + vring_unmap_one_split_indirect(vq, &indir_desc[j], dma); kfree(indir_desc); vq->split.desc_state[head].indir_desc = NULL; @@ -822,6 +841,7 @@ static bool more_used_split(const struct vring_virtqueue *vq) static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, unsigned int *len, + struct virtio_dma_head *dma, void **ctx) { struct vring_virtqueue *vq = to_vvq(_vq); @@ -862,7 +882,7 @@ static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, /* detach_buf_split clears data, so grab it now. */ ret = vq->split.desc_state[i].data; - detach_buf_split(vq, i, ctx); + detach_buf_split(vq, i, dma, ctx); vq->last_used_idx++; /* If we expect an interrupt for the next entry, tell host * by writing event index and flush out the write before @@ -984,7 +1004,7 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq) continue; /* detach_buf_split clears data, so grab it now. */ buf = vq->split.desc_state[i].data; - detach_buf_split(vq, i, NULL); + detach_buf_split(vq, i, NULL, NULL); vq->split.avail_idx_shadow--; vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->split.avail_idx_shadow); @@ -1221,7 +1241,8 @@ static u16 packed_last_used(u16 last_used_idx) } static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, - const struct vring_desc_extra *extra) + const struct vring_desc_extra *extra, + struct virtio_dma_head *dma) { u16 flags; @@ -1235,10 +1256,9 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, extra->addr, extra->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); + } else if (!vq->do_unmap) { + collect_dma_info(vq, dma, extra->addr, extra->len); } else { - if (!vq->do_unmap) - return; - dma_unmap_page(vring_dma_dev(vq), extra->addr, extra->len, (flags & VRING_DESC_F_WRITE) ? @@ -1247,12 +1267,15 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, } static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, - const struct vring_packed_desc *desc) + const struct vring_packed_desc *desc, + struct virtio_dma_head *dma) { u16 flags; - if (!vq->do_unmap) + if (!vq->do_unmap) { + collect_dma_info(vq, dma, le64_to_cpu(desc->addr), le32_to_cpu(desc->len)); return; + } flags = le16_to_cpu(desc->flags); @@ -1389,7 +1412,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, err_idx = i; for (i = 0; i < err_idx; i++) - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_desc_packed(vq, &desc[i], NULL); free_desc: kfree(desc); @@ -1539,7 +1562,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); + vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr], NULL); curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) @@ -1600,7 +1623,9 @@ static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq) } static void detach_buf_packed(struct vring_virtqueue *vq, - unsigned int id, void **ctx) + unsigned int id, + struct virtio_dma_head *dma, + void **ctx) { struct vring_desc_state_packed *state = NULL; struct vring_packed_desc *desc; @@ -1615,13 +1640,10 @@ static void detach_buf_packed(struct vring_virtqueue *vq, vq->free_head = id; vq->vq.num_free += state->num; - if (unlikely(vq->do_unmap)) { - curr = id; - for (i = 0; i < state->num; i++) { - vring_unmap_extra_packed(vq, - &vq->packed.desc_extra[curr]); - curr = vq->packed.desc_extra[curr].next; - } + curr = id; + for (i = 0; i < state->num; i++) { + vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr], dma); + curr = vq->packed.desc_extra[curr].next; } if (vq->indirect) { @@ -1632,12 +1654,9 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (!desc) return; - if (vq->do_unmap) { - len = vq->packed.desc_extra[id].len; - for (i = 0; i < len / sizeof(struct vring_packed_desc); - i++) - vring_unmap_desc_packed(vq, &desc[i]); - } + len = vq->packed.desc_extra[id].len; + for (i = 0; i < len / sizeof(struct vring_packed_desc); i++) + vring_unmap_desc_packed(vq, &desc[i], dma); kfree(desc); state->indir_desc = NULL; } else if (ctx) { @@ -1672,6 +1691,7 @@ static bool more_used_packed(const struct vring_virtqueue *vq) static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, unsigned int *len, + struct virtio_dma_head *dma, void **ctx) { struct vring_virtqueue *vq = to_vvq(_vq); @@ -1712,7 +1732,7 @@ static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, /* detach_buf_packed clears data, so grab it now. */ ret = vq->packed.desc_state[id].data; - detach_buf_packed(vq, id, ctx); + detach_buf_packed(vq, id, dma, ctx); last_used += vq->packed.desc_state[id].num; if (unlikely(last_used >= vq->packed.vring.num)) { @@ -1877,7 +1897,7 @@ static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) continue; /* detach_buf clears data, so grab it now. */ buf = vq->packed.desc_state[i].data; - detach_buf_packed(vq, i, NULL); + detach_buf_packed(vq, i, NULL, NULL); END_USE(vq); return buf; } @@ -2417,11 +2437,44 @@ void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len, { struct vring_virtqueue *vq = to_vvq(_vq); - return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) : - virtqueue_get_buf_ctx_split(_vq, len, ctx); + return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, NULL, ctx) : + virtqueue_get_buf_ctx_split(_vq, len, NULL, ctx); } EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx); +/** + * virtqueue_get_buf_ctx_dma - get the next used buffer with the dma info + * @_vq: the struct virtqueue we're talking about. + * @len: the length written into the buffer + * @dma: the head of the array to store the dma info + * @ctx: extra context for the token + * + * If the device wrote data into the buffer, @len will be set to the + * amount written. This means you don't need to clear the buffer + * beforehand to ensure there's no data leakage in the case of short + * writes. + * + * Caller must ensure we don't call this with other virtqueue + * operations at the same time (except where noted). + * + * We store the dma info of every descriptor of this buf to the dma->items + * array. If the array size is too small, some dma info may be missed, so + * the caller must ensure the array is enough. The dma->next is the out value + * to the caller, indicates the num of the used items. + * + * Returns NULL if there are no used buffers, or the "data" token + * handed to virtqueue_add_*(). + */ +void *virtqueue_get_buf_ctx_dma(struct virtqueue *_vq, unsigned int *len, + struct virtio_dma_head *dma, void **ctx) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, dma, ctx) : + virtqueue_get_buf_ctx_split(_vq, len, dma, ctx); +} +EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx_dma); + void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) { return virtqueue_get_buf_ctx(_vq, len, NULL); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 4cc614a38376..572aecec205b 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -75,6 +75,22 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len, void **ctx); +struct virtio_dma_item { + dma_addr_t addr; + unsigned int length; +}; + +struct virtio_dma_head { + /* total num of items. */ + u16 num; + /* point to the next item to store dma info. */ + u16 next; + struct virtio_dma_item items[]; +}; + +void *virtqueue_get_buf_ctx_dma(struct virtqueue *_vq, unsigned int *len, + struct virtio_dma_head *dma, void **ctx); + void virtqueue_disable_cb(struct virtqueue *vq); bool virtqueue_enable_cb(struct virtqueue *vq); -- 2.32.0.3.g01195cf9f
