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 <[email protected]> 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 <[email protected]> > Message-ID: <[email protected]> > Signed-off-by: Michael S. Tsirkin <[email protected]> > --- > 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
