Hi Michael,
I've tested this on the system that was reproducing the panic, and it
everything is working now as expected.
For the series then:
Tested-by: Darren Kenny <darren.kenny@xxxxxxxxxx>
Thanks,
Darren.
On Wednesday, 2024-08-14 at 02:59:20 -04, Michael S. Tsirkin wrote:
> 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
