This reverts commit defd28aa5acb0fd7c15adc6bc40a8ac277d04dea.
leads to crashes with no ACCESS_PLATFORM when
sysctl net.core.high_order_alloc_disable=1
Reported-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
Message-ID: <8b20cc28-45a9-4643-8e87-ba164a540c0a@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 89 +++++++++++++++++++++++-----------------
1 file changed, 52 insertions(+), 37 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index fd3d7e926022..4f7e686b8bf9 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -348,6 +348,9 @@ struct receive_queue {
/* Record the last dma info to free after new pages is allocated. */
struct virtnet_rq_dma *last_dma;
+
+ /* Do dma by self */
+ bool do_dma;
};
/* This structure can contain rss message with maximum settings for indirection table and keysize
@@ -848,7 +851,7 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx)
void *buf;
buf = virtqueue_get_buf_ctx(rq->vq, len, ctx);
- if (buf)
+ if (buf && rq->do_dma)
virtnet_rq_unmap(rq, buf, *len);
return buf;
@@ -861,6 +864,11 @@ static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len)
u32 offset;
void *head;
+ if (!rq->do_dma) {
+ sg_init_one(rq->sg, buf, len);
+ return;
+ }
+
head = page_address(rq->alloc_frag.page);
offset = buf - head;
@@ -886,42 +894,44 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)
head = page_address(alloc_frag->page);
- dma = head;
+ if (rq->do_dma) {
+ dma = head;
- /* new pages */
- if (!alloc_frag->offset) {
- if (rq->last_dma) {
- /* Now, the new page is allocated, the last dma
- * will not be used. So the dma can be unmapped
- * if the ref is 0.
+ /* new pages */
+ if (!alloc_frag->offset) {
+ if (rq->last_dma) {
+ /* Now, the new page is allocated, the last dma
+ * will not be used. So the dma can be unmapped
+ * if the ref is 0.
+ */
+ virtnet_rq_unmap(rq, rq->last_dma, 0);
+ rq->last_dma = NULL;
+ }
+
+ dma->len = alloc_frag->size - sizeof(*dma);
+
+ addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1,
+ dma->len, DMA_FROM_DEVICE, 0);
+ if (virtqueue_dma_mapping_error(rq->vq, addr))
+ return NULL;
+
+ dma->addr = addr;
+ dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr);
+
+ /* Add a reference to dma to prevent the entire dma from
+ * being released during error handling. This reference
+ * will be freed after the pages are no longer used.
*/
- virtnet_rq_unmap(rq, rq->last_dma, 0);
- rq->last_dma = NULL;
+ get_page(alloc_frag->page);
+ dma->ref = 1;
+ alloc_frag->offset = sizeof(*dma);
+
+ rq->last_dma = dma;
}
- dma->len = alloc_frag->size - sizeof(*dma);
-
- addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1,
- dma->len, DMA_FROM_DEVICE, 0);
- if (virtqueue_dma_mapping_error(rq->vq, addr))
- return NULL;
-
- dma->addr = addr;
- dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr);
-
- /* Add a reference to dma to prevent the entire dma from
- * being released during error handling. This reference
- * will be freed after the pages are no longer used.
- */
- get_page(alloc_frag->page);
- dma->ref = 1;
- alloc_frag->offset = sizeof(*dma);
-
- rq->last_dma = dma;
+ ++dma->ref;
}
- ++dma->ref;
-
buf = head + alloc_frag->offset;
get_page(alloc_frag->page);
@@ -938,9 +948,12 @@ static void virtnet_rq_set_premapped(struct virtnet_info *vi)
if (!vi->mergeable_rx_bufs && vi->big_packets)
return;
- for (i = 0; i < vi->max_queue_pairs; i++)
- /* error should never happen */
- BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq));
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ if (virtqueue_set_dma_premapped(vi->rq[i].vq))
+ continue;
+
+ vi->rq[i].do_dma = true;
+ }
}
static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
@@ -2036,7 +2049,8 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
if (err < 0) {
- virtnet_rq_unmap(rq, buf, 0);
+ if (rq->do_dma)
+ virtnet_rq_unmap(rq, buf, 0);
put_page(virt_to_head_page(buf));
}
@@ -2150,7 +2164,8 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
ctx = mergeable_len_to_ctx(len + room, headroom);
err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
if (err < 0) {
- virtnet_rq_unmap(rq, buf, 0);
+ if (rq->do_dma)
+ virtnet_rq_unmap(rq, buf, 0);
put_page(virt_to_head_page(buf));
}
@@ -5231,7 +5246,7 @@ static void free_receive_page_frags(struct virtnet_info *vi)
int i;
for (i = 0; i < vi->max_queue_pairs; i++)
if (vi->rq[i].alloc_frag.page) {
- if (vi->rq[i].last_dma)
+ if (vi->rq[i].do_dma && vi->rq[i].last_dma)
virtnet_rq_unmap(&vi->rq[i], vi->rq[i].last_dma, 0);
put_page(vi->rq[i].alloc_frag.page);
}
--
MST
