virtqueue_add() only supports virtual addresses, dma is completed in
virtqueue_add().
In some scenarios (such as the AF_XDP scenario), DMA is completed in advance, so
it is necessary for us to support passing the DMA address to virtqueue_add().
Record this predma information in extra->flags, which can be skipped when
executing dma unmap.
v1:
1. All sgs requested at one time are required to be unified PREDMA, and
several
of them are not supported to be PREDMA
2. virtio_dma_map() is removed from this patch set and will be submitted
together with the next time AF_XDP supports virtio dma
3. Added patch #2 #3 to remove the check for flags when performing unmap
indirect desc
Xuan Zhuo (6):
virtio: rename vring_unmap_state_packed() to
vring_unmap_extra_packed()
virtio: remove flags check for unmap split indirect desc
virtio: remove flags check for unmap packed indirect desc
virtio: virtqueue_add() support predma
virtio: split: virtqueue_add_split() support dma address
virtio: packed: virtqueue_add_packed() support dma address
drivers/virtio/virtio_ring.c | 199 ++++++++++++++++++++++-------------
1 file changed, 126 insertions(+), 73 deletions(-)
--
2.31.0
Xuan Zhuo
2022-Feb-10 08:51 UTC
[PATCH v1 1/6] virtio: rename vring_unmap_state_packed() to vring_unmap_extra_packed()
The actual parameter handled by vring_unmap_state_packed() is that
vring_desc_extra, so this function should use "extra" instead of
"state".
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 962f1477b1fa..7cf3ae057833 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -984,24 +984,24 @@ static struct virtqueue *vring_create_virtqueue_split(
* Packed ring specific functions - *_packed().
*/
-static void vring_unmap_state_packed(const struct vring_virtqueue *vq,
- struct vring_desc_extra *state)
+static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
+ struct vring_desc_extra *extra)
{
u16 flags;
if (!vq->use_dma_api)
return;
- flags = state->flags;
+ flags = extra->flags;
if (flags & VRING_DESC_F_INDIRECT) {
dma_unmap_single(vring_dma_dev(vq),
- state->addr, state->len,
+ extra->addr, extra->len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
dma_unmap_page(vring_dma_dev(vq),
- state->addr, state->len,
+ extra->addr, extra->len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
@@ -1303,8 +1303,7 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
for (n = 0; n < total_sg; n++) {
if (i == err_idx)
break;
- vring_unmap_state_packed(vq,
- &vq->packed.desc_extra[curr]);
+ vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]);
curr = vq->packed.desc_extra[curr].next;
i++;
if (i >= vq->packed.vring.num)
@@ -1383,8 +1382,8 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
if (unlikely(vq->use_dma_api)) {
curr = id;
for (i = 0; i < state->num; i++) {
- vring_unmap_state_packed(vq,
- &vq->packed.desc_extra[curr]);
+ vring_unmap_extra_packed(vq,
+ &vq->packed.desc_extra[curr]);
curr = vq->packed.desc_extra[curr].next;
}
}
--
2.31.0
Xuan Zhuo
2022-Feb-10 08:51 UTC
[PATCH v1 2/6] virtio: remove flags check for unmap split indirect desc
When calling vring_unmap_one_split_indirect(), it will not encounter the
situation that the flags contains VRING_DESC_F_INDIRECT. So remove this
logic.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 7cf3ae057833..fadd0a7503e9 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -379,19 +379,11 @@ static void vring_unmap_one_split_indirect(const struct
vring_virtqueue *vq,
flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
- if (flags & VRING_DESC_F_INDIRECT) {
- dma_unmap_single(vring_dma_dev(vq),
- virtio64_to_cpu(vq->vq.vdev, desc->addr),
- virtio32_to_cpu(vq->vq.vdev, desc->len),
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- } else {
- dma_unmap_page(vring_dma_dev(vq),
- virtio64_to_cpu(vq->vq.vdev, desc->addr),
- virtio32_to_cpu(vq->vq.vdev, desc->len),
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- }
+ dma_unmap_page(vring_dma_dev(vq),
+ virtio64_to_cpu(vq->vq.vdev, desc->addr),
+ virtio32_to_cpu(vq->vq.vdev, desc->len),
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
--
2.31.0
Xuan Zhuo
2022-Feb-10 08:51 UTC
[PATCH v1 3/6] virtio: remove flags check for unmap packed indirect desc
When calling vring_unmap_desc_packed(), it will not encounter the
situation that the flags contains VRING_DESC_F_INDIRECT. So remove this
logic.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index fadd0a7503e9..cfb028ca238e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1009,19 +1009,11 @@ static void vring_unmap_desc_packed(const struct
vring_virtqueue *vq,
flags = le16_to_cpu(desc->flags);
- if (flags & VRING_DESC_F_INDIRECT) {
- dma_unmap_single(vring_dma_dev(vq),
- le64_to_cpu(desc->addr),
- le32_to_cpu(desc->len),
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- } else {
- dma_unmap_page(vring_dma_dev(vq),
- le64_to_cpu(desc->addr),
- le32_to_cpu(desc->len),
- (flags & VRING_DESC_F_WRITE) ?
- DMA_FROM_DEVICE : DMA_TO_DEVICE);
- }
+ dma_unmap_page(vring_dma_dev(vq),
+ le64_to_cpu(desc->addr),
+ le32_to_cpu(desc->len),
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
--
2.31.0
virtuque_add() adds parameter predma.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cfb028ca238e..cf9d118668f1 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1780,7 +1780,8 @@ static inline int virtqueue_add(struct virtqueue *_vq,
unsigned int in_sgs,
void *data,
void *ctx,
- gfp_t gfp)
+ gfp_t gfp,
+ bool predma)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -1821,7 +1822,7 @@ int virtqueue_add_sgs(struct virtqueue *_vq,
total_sg++;
}
return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
- data, NULL, gfp);
+ data, NULL, gfp, false);
}
EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
@@ -1843,7 +1844,7 @@ int virtqueue_add_outbuf(struct virtqueue *vq,
void *data,
gfp_t gfp)
{
- return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
+ return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp, false);
}
EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
@@ -1865,7 +1866,7 @@ int virtqueue_add_inbuf(struct virtqueue *vq,
void *data,
gfp_t gfp)
{
- return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
+ return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp, false);
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
@@ -1889,7 +1890,7 @@ int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
void *ctx,
gfp_t gfp)
{
- return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
+ return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp, false);
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
--
2.31.0
Xuan Zhuo
2022-Feb-10 08:51 UTC
[PATCH v1 5/6] virtio: split: virtqueue_add_split() support dma address
virtqueue_add_split() only supports virtual addresses, dma is completed
in virtqueue_add_split().
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 virtqueue_add_split().
And record this predma information in extra->flags, which can be skipped
when executing dma unmap.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 62 ++++++++++++++++++++++++++++--------
1 file changed, 48 insertions(+), 14 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cf9d118668f1..d32c0bf6016f 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -66,6 +66,9 @@
#define LAST_ADD_TIME_INVALID(vq)
#endif
+/* This means the buffer dma is pre-alloc. Just used by vring_desc_extra */
+#define VIRTIO_DESC_F_PREDMA (1 << 15)
+
struct vring_desc_state_split {
void *data; /* Data for callback. */
struct vring_desc *indir_desc; /* Indirect descriptor, if any. */
@@ -387,7 +390,7 @@ 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, bool predma)
{
struct vring_desc_extra *extra = vq->split.desc_extra;
u16 flags;
@@ -404,6 +407,9 @@ static unsigned int vring_unmap_one_split(const struct
vring_virtqueue *vq,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
+ if (predma)
+ goto out;
+
dma_unmap_page(vring_dma_dev(vq),
extra[i].addr,
extra[i].len,
@@ -474,7 +480,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
unsigned int in_sgs,
void *data,
void *ctx,
- gfp_t gfp)
+ gfp_t gfp,
+ bool predma)
{
struct vring_virtqueue *vq = to_vvq(_vq);
struct scatterlist *sg;
@@ -535,9 +542,16 @@ static inline int virtqueue_add_split(struct virtqueue
*_vq,
for (n = 0; n < out_sgs; n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE);
- if (vring_mapping_error(vq, addr))
- goto unmap_release;
+ dma_addr_t addr;
+
+ if (predma) {
+ addr = sg_dma_address(sg);
+
+ } else {
+ addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+ }
prev = i;
/* Note that we trust indirect descriptor
@@ -550,9 +564,16 @@ static inline int virtqueue_add_split(struct virtqueue
*_vq,
}
for (; n < (out_sgs + in_sgs); n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE);
- if (vring_mapping_error(vq, addr))
- goto unmap_release;
+ dma_addr_t addr;
+
+ if (predma) {
+ addr = sg_dma_address(sg);
+
+ } else {
+ addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+ }
prev = i;
/* Note that we trust indirect descriptor
@@ -602,6 +623,9 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
else
vq->split.desc_state[head].indir_desc = ctx;
+ if (predma)
+ vq->split.desc_extra[head].flags |= VIRTIO_DESC_F_PREDMA;
+
/* Put entry in available array (but don't update avail->idx until they
* do sync). */
avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1);
@@ -626,6 +650,9 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
return 0;
unmap_release:
+ if (predma)
+ goto skip_unmap;
+
err_idx = i;
if (indirect)
@@ -640,9 +667,10 @@ static inline int virtqueue_add_split(struct virtqueue
*_vq,
vring_unmap_one_split_indirect(vq, &desc[i]);
i = virtio16_to_cpu(_vq->vdev, desc[i].next);
} else
- i = vring_unmap_one_split(vq, i);
+ i = vring_unmap_one_split(vq, i, false);
}
+skip_unmap:
if (indirect)
kfree(desc);
@@ -686,20 +714,24 @@ static void detach_buf_split(struct vring_virtqueue *vq,
unsigned int head,
{
unsigned int i, j;
__virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
+ bool predma = false;
/* Clear data ptr. */
vq->split.desc_state[head].data = NULL;
+ if (vq->split.desc_extra[head].flags & VIRTIO_DESC_F_PREDMA)
+ predma = true;
+
/* Put back on free list: unmap first-level descriptors and find end */
i = head;
while (vq->split.vring.desc[i].flags & nextflag) {
- vring_unmap_one_split(vq, i);
+ vring_unmap_one_split(vq, i, predma);
i = vq->split.desc_extra[i].next;
vq->vq.num_free++;
}
- vring_unmap_one_split(vq, i);
+ vring_unmap_one_split(vq, i, predma);
vq->split.desc_extra[i].next = vq->free_head;
vq->free_head = head;
@@ -721,8 +753,10 @@ 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));
- for (j = 0; j < len / sizeof(struct vring_desc); j++)
- vring_unmap_one_split_indirect(vq, &indir_desc[j]);
+ if (!predma) {
+ for (j = 0; j < len / sizeof(struct vring_desc); j++)
+ vring_unmap_one_split_indirect(vq, &indir_desc[j]);
+ }
kfree(indir_desc);
vq->split.desc_state[head].indir_desc = NULL;
@@ -1788,7 +1822,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg,
out_sgs, in_sgs, data, ctx, gfp) :
virtqueue_add_split(_vq, sgs, total_sg,
- out_sgs, in_sgs, data, ctx, gfp);
+ out_sgs, in_sgs, data, ctx, gfp, predma);
}
/**
--
2.31.0
Xuan Zhuo
2022-Feb-10 08:51 UTC
[PATCH v1 6/6] virtio: packed: virtqueue_add_packed() support dma address
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 virtqueue_add_packed().
Record this predma information in extra->flags, which can be skipped
when executing dma unmap.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 79 ++++++++++++++++++++++++++----------
1 file changed, 57 insertions(+), 22 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d32c0bf6016f..b8c7697e925d 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1011,7 +1011,8 @@ static struct virtqueue *vring_create_virtqueue_split(
*/
static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
- struct vring_desc_extra *extra)
+ struct vring_desc_extra *extra,
+ bool predma)
{
u16 flags;
@@ -1026,6 +1027,9 @@ static void vring_unmap_extra_packed(const struct
vring_virtqueue *vq,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
+ if (predma)
+ return;
+
dma_unmap_page(vring_dma_dev(vq),
extra->addr, extra->len,
(flags & VRING_DESC_F_WRITE) ?
@@ -1073,7 +1077,8 @@ static int virtqueue_add_indirect_packed(struct
vring_virtqueue *vq,
unsigned int out_sgs,
unsigned int in_sgs,
void *data,
- gfp_t gfp)
+ gfp_t gfp,
+ bool predma)
{
struct vring_packed_desc *desc;
struct scatterlist *sg;
@@ -1099,10 +1104,15 @@ static int virtqueue_add_indirect_packed(struct
vring_virtqueue *vq,
for (n = 0; n < out_sgs + in_sgs; n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- addr = vring_map_one_sg(vq, sg, n < out_sgs ?
- DMA_TO_DEVICE : DMA_FROM_DEVICE);
- if (vring_mapping_error(vq, addr))
- goto unmap_release;
+ if (predma) {
+ addr = sg_dma_address(sg);
+
+ } else {
+ addr = vring_map_one_sg(vq, sg, n < out_sgs ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+ }
desc[i].flags = cpu_to_le16(n < out_sgs ?
0 : VRING_DESC_F_WRITE);
@@ -1132,6 +1142,9 @@ static int virtqueue_add_indirect_packed(struct
vring_virtqueue *vq,
vq->packed.avail_used_flags;
}
+ if (predma)
+ vq->packed.desc_extra[id].flags |= VIRTIO_DESC_F_PREDMA;
+
/*
* A driver MUST NOT make the first descriptor in the list
* available before all subsequent descriptors comprising
@@ -1170,10 +1183,11 @@ static int virtqueue_add_indirect_packed(struct
vring_virtqueue *vq,
return 0;
unmap_release:
- err_idx = i;
-
- for (i = 0; i < err_idx; i++)
- vring_unmap_desc_packed(vq, &desc[i]);
+ if (!predma) {
+ err_idx = i;
+ for (i = 0; i < err_idx; i++)
+ vring_unmap_desc_packed(vq, &desc[i]);
+ }
kfree(desc);
@@ -1188,7 +1202,8 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
unsigned int in_sgs,
void *data,
void *ctx,
- gfp_t gfp)
+ gfp_t gfp,
+ bool predma)
{
struct vring_virtqueue *vq = to_vvq(_vq);
struct vring_packed_desc *desc;
@@ -1214,7 +1229,7 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
if (virtqueue_use_indirect(_vq, total_sg)) {
err = virtqueue_add_indirect_packed(vq, sgs, total_sg, out_sgs,
- in_sgs, data, gfp);
+ in_sgs, data, gfp, predma);
if (err != -ENOMEM) {
END_USE(vq);
return err;
@@ -1246,10 +1261,17 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
c = 0;
for (n = 0; n < out_sgs + in_sgs; n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ?
- DMA_TO_DEVICE : DMA_FROM_DEVICE);
- if (vring_mapping_error(vq, addr))
- goto unmap_release;
+ dma_addr_t addr;
+
+ if (predma) {
+ addr = sg_dma_address(sg);
+
+ } else {
+ addr = vring_map_one_sg(vq, sg, n < out_sgs ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+ }
flags = cpu_to_le16(vq->packed.avail_used_flags |
(++c == total_sg ? 0 : VRING_DESC_F_NEXT) |
@@ -1297,6 +1319,9 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
vq->packed.desc_state[id].indir_desc = ctx;
vq->packed.desc_state[id].last = prev;
+ if (predma)
+ vq->packed.desc_extra[id].flags |= VIRTIO_DESC_F_PREDMA;
+
/*
* A driver MUST NOT make the first descriptor in the list
* available before all subsequent descriptors comprising
@@ -1312,22 +1337,27 @@ static inline int virtqueue_add_packed(struct virtqueue
*_vq,
return 0;
unmap_release:
+ vq->packed.avail_used_flags = avail_used_flags;
+
+ if (predma)
+ goto skip_unmap;
+
err_idx = i;
i = head;
curr = vq->free_head;
- vq->packed.avail_used_flags = avail_used_flags;
-
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], false);
curr = vq->packed.desc_extra[curr].next;
i++;
if (i >= vq->packed.vring.num)
i = 0;
}
+skip_unmap:
+
END_USE(vq);
return -EIO;
}
@@ -1387,9 +1417,13 @@ 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 predma = false;
state = &vq->packed.desc_state[id];
+ if (vq->packed.desc_extra[state->last].flags & VIRTIO_DESC_F_PREDMA)
+ predma = true;
+
/* Clear data ptr. */
state->data = NULL;
@@ -1401,7 +1435,8 @@ 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],
+ predma);
curr = vq->packed.desc_extra[curr].next;
}
}
@@ -1414,7 +1449,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
if (!desc)
return;
- if (vq->use_dma_api) {
+ if (vq->use_dma_api && !predma) {
len = vq->packed.desc_extra[id].len;
for (i = 0; i < len / sizeof(struct vring_packed_desc);
i++)
@@ -1820,7 +1855,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg,
- out_sgs, in_sgs, data, ctx, gfp) :
+ out_sgs, in_sgs, data, ctx, gfp, predma) :
virtqueue_add_split(_vq, sgs, total_sg,
out_sgs, in_sgs, data, ctx, gfp, predma);
}
--
2.31.0
On Thu, Feb 10, 2022 at 4:51 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > virtqueue_add() only supports virtual addresses, dma is completed in > virtqueue_add(). > > In some scenarios (such as the AF_XDP scenario), DMA is completed in advance, so > it is necessary for us to support passing the DMA address to virtqueue_add().I'd suggest rename this feature as "unmanaged DMA".> > Record this predma information in extra->flags, which can be skipped when > executing dma unmap.Question still, can we use per-virtqueue flag instead of per descriptor flag? If my memory is correct, the answer is yes in the discussion for the previous version. Thanks> > v1: > 1. All sgs requested at one time are required to be unified PREDMA, and several > of them are not supported to be PREDMA > 2. virtio_dma_map() is removed from this patch set and will be submitted > together with the next time AF_XDP supports virtio dma > 3. Added patch #2 #3 to remove the check for flags when performing unmap > indirect desc > > Xuan Zhuo (6): > virtio: rename vring_unmap_state_packed() to > vring_unmap_extra_packed() > virtio: remove flags check for unmap split indirect desc > virtio: remove flags check for unmap packed indirect desc > virtio: virtqueue_add() support predma > virtio: split: virtqueue_add_split() support dma address > virtio: packed: virtqueue_add_packed() support dma address > > drivers/virtio/virtio_ring.c | 199 ++++++++++++++++++++++------------- > 1 file changed, 126 insertions(+), 73 deletions(-) > > -- > 2.31.0 >