virtqueue_add_packed() only supports virtual addresses, dma is completed
in virtqueue_add_packed().
In some scenarios (such as the AF_XDP scenario), the memory is allocated
and DMA is completed in advance, so it is necessary for us to support
passing the DMA address to virtio core.
Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 67 ++++++++++++++++++++++++++++++++----
1 file changed, 61 insertions(+), 6 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index a31155abe101..79244ccbae9e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -78,6 +78,7 @@ struct vring_desc_state_packed {
struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */
u16 num; /* Descriptor list length. */
u16 last; /* The last desc state in a list. */
+ bool premapped;
};
struct vring_desc_extra {
@@ -1318,7 +1319,8 @@ static inline u16 packed_last_used(u16 last_used_idx)
}
static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
- struct vring_desc_extra *extra)
+ struct vring_desc_extra *extra,
+ bool premapped)
{
u16 flags;
@@ -1333,6 +1335,9 @@ static void vring_unmap_extra_packed(const struct
vring_virtqueue *vq,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
+ if (premapped)
+ return;
+
dma_unmap_page(vring_dma_dev(vq),
extra->addr, extra->len,
(flags & VRING_DESC_F_WRITE) ?
@@ -1382,7 +1387,7 @@ static int virtqueue_add_indirect_packed(struct
vring_virtqueue *vq,
struct vring_packed_desc *desc)
{
struct scatterlist *sg;
- unsigned int i, n, err_idx;
+ unsigned int i, n;
u16 head, id;
dma_addr_t addr;
@@ -1640,6 +1645,51 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
return err;
}
+static inline int virtqueue_add_packed_premapped(struct virtqueue *_vq,
+ struct scatterlist *sgs[],
+ unsigned int total_sg,
+ unsigned int out_sgs,
+ unsigned int in_sgs,
+ void *data,
+ void *ctx,
+ gfp_t gfp)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ struct vring_packed_desc *desc;
+ u16 id;
+ int err;
+
+ START_USE(vq);
+
+ /* check vq state and try to alloc desc for indirect. */
+ err = virtqueue_add_packed_prepare(vq, total_sg, data, ctx, &desc, gfp);
+ if (err)
+ goto end;
+
+ id = vq->free_head;
+
+ if (desc) {
+ err = virtqueue_add_indirect_packed(vq, sgs, total_sg, out_sgs,
in_sgs, desc);
+ if (err)
+ goto err;
+ } else {
+ virtqueue_add_packed_vring(vq, sgs, total_sg, out_sgs, in_sgs);
+ vq->packed.desc_state[id].indir_desc = ctx;
+ }
+
+ vq->packed.desc_state[id].data = data;
+ vq->packed.desc_state[id].premapped = true;
+
+ goto end;
+
+err:
+ kfree(desc);
+
+end:
+ END_USE(vq);
+ return err;
+}
+
static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -1695,8 +1745,10 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
struct vring_desc_state_packed *state = NULL;
struct vring_packed_desc *desc;
unsigned int i, curr;
+ bool premapped;
state = &vq->packed.desc_state[id];
+ premapped = state->premapped;
/* Clear data ptr. */
state->data = NULL;
@@ -1709,7 +1761,8 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
curr = id;
for (i = 0; i < state->num; i++) {
vring_unmap_extra_packed(vq,
- &vq->packed.desc_extra[curr]);
+ &vq->packed.desc_extra[curr],
+ premapped);
curr = vq->packed.desc_extra[curr].next;
}
}
@@ -1722,7 +1775,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
if (!desc)
return;
- if (vq->use_dma_api) {
+ if (vq->use_dma_api && !premapped) {
len = vq->packed.desc_extra[id].len;
for (i = 0; i < len / sizeof(struct vring_packed_desc);
i++)
@@ -2265,8 +2318,10 @@ static inline int virtqueue_add_premapped(struct
virtqueue *_vq,
{
struct vring_virtqueue *vq = to_vvq(_vq);
- return virtqueue_add_split_premapped(_vq, sgs, total_sg, out_sgs,
- in_sgs, data, ctx, gfp);
+ return vq->packed_ring ? virtqueue_add_packed_premapped(_vq, sgs,
total_sg, out_sgs,
+ in_sgs, data,
ctx, gfp) :
+ virtqueue_add_split_premapped(_vq, sgs,
total_sg, out_sgs,
+ in_sgs, data,
ctx, gfp);
}
/**
--
2.32.0.3.g01195cf9f
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