1. this commit hardens dma unmap for indirect
2. the subsequent commit uses the struct extra to record whether the
buffers need to be unmapped or not. So we need a struct extra for
every desc, whatever it is indirect or not.
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 122 ++++++++++++++++-------------------
1 file changed, 57 insertions(+), 65 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 228e9fbcba3f..582d2c05498a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -67,9 +67,16 @@
#define LAST_ADD_TIME_INVALID(vq)
#endif
+struct vring_desc_extra {
+ dma_addr_t addr; /* Descriptor DMA addr. */
+ u32 len; /* Descriptor length. */
+ u16 flags; /* Descriptor flags. */
+ u16 next; /* The next desc state in a list. */
+};
+
struct vring_desc_state_split {
void *data; /* Data for callback. */
- struct vring_desc *indir_desc; /* Indirect descriptor, if any. */
+ struct vring_desc_extra *indir; /* Indirect descriptor, if any. */
};
struct vring_desc_state_packed {
@@ -79,13 +86,6 @@ struct vring_desc_state_packed {
u16 last; /* The last desc state in a list. */
};
-struct vring_desc_extra {
- dma_addr_t addr; /* Descriptor DMA addr. */
- u32 len; /* Descriptor length. */
- u16 flags; /* Descriptor flags. */
- u16 next; /* The next desc state in a list. */
-};
-
struct vring_virtqueue_split {
/* Actual memory layout for this queue. */
struct vring vring;
@@ -440,38 +440,20 @@ static void virtqueue_init(struct vring_virtqueue *vq, u32 num)
* Split ring specific functions - *_split().
*/
-static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq,
- const struct vring_desc *desc)
-{
- u16 flags;
-
- if (!vring_need_unmap_buffer(vq))
- return;
-
- flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
-
- 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,
- unsigned int i)
+ struct vring_desc_extra *extra)
{
- struct vring_desc_extra *extra = vq->split.desc_extra;
u16 flags;
- flags = extra[i].flags;
+ flags = extra->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,
+ extra->addr,
+ extra->len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
@@ -479,20 +461,22 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
goto out;
dma_unmap_page(vring_dma_dev(vq),
- extra[i].addr,
- extra[i].len,
+ extra->addr,
+ extra->len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
out:
- return extra[i].next;
+ return extra->next;
}
static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq,
unsigned int total_sg,
+ struct vring_desc_extra **pextra,
gfp_t gfp)
{
+ struct vring_desc_extra *extra;
struct vring_desc *desc;
unsigned int i;
@@ -503,40 +487,45 @@ static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq,
*/
gfp &= ~__GFP_HIGHMEM;
- desc = kmalloc_array(total_sg, sizeof(struct vring_desc), gfp);
- if (!desc)
+ extra = kmalloc_array(total_sg, sizeof(*desc) + sizeof(*extra), gfp);
+ if (!extra)
return NULL;
- for (i = 0; i < total_sg; i++)
+ desc = (struct vring_desc *)&extra[total_sg];
+
+ for (i = 0; i < total_sg; i++) {
desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1);
+ extra[i].next = i + 1;
+ }
+
+ *pextra = extra;
+
return desc;
}
static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq,
struct vring_desc *desc,
+ struct vring_desc_extra *extra,
unsigned int i,
dma_addr_t addr,
unsigned int len,
u16 flags,
bool indirect)
{
- struct vring_virtqueue *vring = to_vvq(vq);
- struct vring_desc_extra *extra = vring->split.desc_extra;
u16 next;
desc[i].flags = cpu_to_virtio16(vq->vdev, flags);
desc[i].addr = cpu_to_virtio64(vq->vdev, addr);
desc[i].len = cpu_to_virtio32(vq->vdev, len);
- if (!indirect) {
- next = extra[i].next;
- desc[i].next = cpu_to_virtio16(vq->vdev, next);
+ extra[i].addr = addr;
+ extra[i].len = len;
+ extra[i].flags = flags;
- extra[i].addr = addr;
- extra[i].len = len;
- extra[i].flags = flags;
- } else
- next = virtio16_to_cpu(vq->vdev, desc[i].next);
+ next = extra[i].next;
+
+ if (!indirect)
+ desc[i].next = cpu_to_virtio16(vq->vdev, next);
return next;
}
@@ -551,6 +540,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
gfp_t gfp)
{
struct vring_virtqueue *vq = to_vvq(_vq);
+ struct vring_desc_extra *extra;
struct scatterlist *sg;
struct vring_desc *desc;
unsigned int i, n, avail, descs_used, prev, err_idx;
@@ -574,7 +564,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
head = vq->free_head;
if (virtqueue_use_indirect(vq, total_sg))
- desc = alloc_indirect_split(_vq, total_sg, gfp);
+ desc = alloc_indirect_split(_vq, total_sg, &extra, gfp);
else {
desc = NULL;
WARN_ON_ONCE(total_sg > vq->split.vring.num && !vq->indirect);
@@ -589,6 +579,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
} else {
indirect = false;
desc = vq->split.vring.desc;
+ extra = vq->split.desc_extra;
i = head;
descs_used = total_sg;
}
@@ -618,7 +609,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
/* Note that we trust indirect descriptor
* table since it use stream DMA mapping.
*/
- i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length,
+ i = virtqueue_add_desc_split(_vq, desc, extra, i, addr, sg->length,
VRING_DESC_F_NEXT,
indirect);
}
@@ -634,7 +625,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
/* Note that we trust indirect descriptor
* table since it use stream DMA mapping.
*/
- i = virtqueue_add_desc_split(_vq, desc, i, addr,
+ i = virtqueue_add_desc_split(_vq, desc, extra, i, addr,
sg->length,
VRING_DESC_F_NEXT |
VRING_DESC_F_WRITE,
@@ -660,6 +651,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
}
virtqueue_add_desc_split(_vq, vq->split.vring.desc,
+ vq->split.desc_extra,
head, addr,
total_sg * sizeof(struct vring_desc),
VRING_DESC_F_INDIRECT,
@@ -678,9 +670,9 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
/* Store token and indirect buffer state. */
vq->split.desc_state[head].data = data;
if (indirect)
- vq->split.desc_state[head].indir_desc = desc;
+ vq->split.desc_state[head].indir = extra;
else
- vq->split.desc_state[head].indir_desc = ctx;
+ vq->split.desc_state[head].indir = ctx;
/* Put entry in available array (but don't update avail->idx until they
* do sync). */
@@ -716,11 +708,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
for (n = 0; n < total_sg; n++) {
if (i == err_idx)
break;
- if (indirect) {
- 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, &extra[i]);
}
free_indirect:
@@ -765,22 +754,25 @@ static bool virtqueue_kick_prepare_split(struct virtqueue *_vq)
static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
void **ctx)
{
+ struct vring_desc_extra *extra;
unsigned int i, j;
__virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
/* Clear data ptr. */
vq->split.desc_state[head].data = NULL;
+ extra = vq->split.desc_extra;
+
/* 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, &extra[i]);
i = vq->split.desc_extra[i].next;
vq->vq.num_free++;
}
- vring_unmap_one_split(vq, i);
+ vring_unmap_one_split(vq, &extra[i]);
vq->split.desc_extra[i].next = vq->free_head;
vq->free_head = head;
@@ -788,12 +780,12 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
vq->vq.num_free++;
if (vq->indirect) {
- struct vring_desc *indir_desc =
- vq->split.desc_state[head].indir_desc;
u32 len;
+ extra = vq->split.desc_state[head].indir;
+
/* Free the indirect table, if any, now that it's unmapped. */
- if (!indir_desc)
+ if (!extra)
return;
len = vq->split.desc_extra[head].len;
@@ -804,13 +796,13 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
if (vring_need_unmap_buffer(vq)) {
for (j = 0; j < len / sizeof(struct vring_desc); j++)
- vring_unmap_one_split_indirect(vq, &indir_desc[j]);
+ vring_unmap_one_split(vq, &extra[j]);
}
- kfree(indir_desc);
- vq->split.desc_state[head].indir_desc = NULL;
+ kfree(extra);
+ vq->split.desc_state[head].indir = NULL;
} else if (ctx) {
- *ctx = vq->split.desc_state[head].indir_desc;
+ *ctx = vq->split.desc_state[head].indir;
}
}
--
2.32.0.3.g01195cf9f
