From f9dac92ba9081062a6477ee015bd3b8c5914efc4 Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Sat, 11 May 2024 11:14:01 +0800 Subject: virtio_ring: enable premapped mode whatever use_dma_api Now, we have virtio DMA APIs, the driver can be the premapped mode whatever the virtio core uses dma api or not. So remove the limit of checking use_dma_api from virtqueue_set_dma_premapped(). Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Link: https://lore.kernel.org/r/20240511031404.30903-2-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski --- drivers/virtio/virtio_ring.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 6f7e5010a673..2a972752ff1b 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2782,7 +2782,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize); * * Returns zero or a negative error. * 0: success. - * -EINVAL: vring does not use the dma api, so we can not enable premapped mode. + * -EINVAL: too late to enable premapped mode, the vq already contains buffers. */ int virtqueue_set_dma_premapped(struct virtqueue *_vq) { @@ -2798,11 +2798,6 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq) return -EINVAL; } - if (!vq->use_dma_api) { - END_USE(vq); - return -EINVAL; - } - vq->premapped = true; vq->do_unmap = false; -- cgit v1.2.3 From a377ae542d8d0a20a3173da3bbba72e045bea7a9 Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Sat, 11 May 2024 11:14:02 +0800 Subject: virtio_net: big mode skip the unmap check The virtio-net big mode did not enable premapped mode, so we did not need to check the unmap. And the subsequent commit will remove the failover code for failing enable premapped for merge and small mode. So we need to remove the checking do_dma code in the big mode path. Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Link: https://lore.kernel.org/r/20240511031404.30903-3-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski --- drivers/net/virtio_net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 42da535913ed..b53016c5e8df 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -963,7 +963,7 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) rq = &vi->rq[i]; - if (rq->do_dma) + if (!vi->big_packets || vi->mergeable_rx_bufs) virtnet_rq_unmap(rq, buf, 0); virtnet_rq_free_buf(vi, rq, buf); @@ -2277,7 +2277,7 @@ static int virtnet_receive(struct receive_queue *rq, int budget, } } else { while (packets < budget && - (buf = virtnet_rq_get_buf(rq, &len, NULL)) != NULL) { + (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats); packets++; } -- cgit v1.2.3 From defd28aa5acb0fd7c15adc6bc40a8ac277d04dea Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Sat, 11 May 2024 11:14:03 +0800 Subject: virtio_net: rx remove premapped failover code Now, the premapped mode can be enabled unconditionally. So we can remove the failover code for merge and small mode. Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Reviewed-by: Larysa Zaremba Link: https://lore.kernel.org/r/20240511031404.30903-4-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski --- drivers/net/virtio_net.c | 85 ++++++++++++++++++++---------------------------- 1 file changed, 35 insertions(+), 50 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index b53016c5e8df..2f8f0de21dc6 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -348,9 +348,6 @@ 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 @@ -850,7 +847,7 @@ 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 && rq->do_dma) + if (buf) virtnet_rq_unmap(rq, buf, *len); return buf; @@ -863,11 +860,6 @@ 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; @@ -893,44 +885,42 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp) head = page_address(alloc_frag->page); - 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. - */ - virtnet_rq_unmap(rq, rq->last_dma, 0); - rq->last_dma = NULL; - } + dma = head; - dma->len = alloc_frag->size - sizeof(*dma); + /* 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; + } - 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->len = alloc_frag->size - sizeof(*dma); - dma->addr = addr; - dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr); + 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; - /* 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); + dma->addr = addr; + dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr); - rq->last_dma = dma; - } + /* 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); - ++dma->ref; + rq->last_dma = dma; } + ++dma->ref; + buf = head + alloc_frag->offset; get_page(alloc_frag->page); @@ -947,12 +937,9 @@ 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++) { - if (virtqueue_set_dma_premapped(vi->rq[i].vq)) - continue; - - vi->rq[i].do_dma = true; - } + for (i = 0; i < vi->max_queue_pairs; i++) + /* error should never happen */ + BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq)); } static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) @@ -2030,8 +2017,7 @@ 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) { - if (rq->do_dma) - virtnet_rq_unmap(rq, buf, 0); + virtnet_rq_unmap(rq, buf, 0); put_page(virt_to_head_page(buf)); } @@ -2145,8 +2131,7 @@ 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) { - if (rq->do_dma) - virtnet_rq_unmap(rq, buf, 0); + virtnet_rq_unmap(rq, buf, 0); put_page(virt_to_head_page(buf)); } @@ -5229,7 +5214,7 @@ 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].do_dma && vi->rq[i].last_dma) + if (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); } -- cgit v1.2.3 From 9719f039d3287e70e6f0b6368dba5b112d152a8f Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Sat, 11 May 2024 11:14:04 +0800 Subject: virtio_net: remove the misleading comment We call the build_skb() actually without copying data. The comment is misleading. So remove it. Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Link: https://lore.kernel.org/r/20240511031404.30903-5-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski --- drivers/net/virtio_net.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 2f8f0de21dc6..19a9b50646c7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -743,7 +743,6 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - /* copy small packet so we can reuse these pages */ if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) { skb = virtnet_build_skb(buf, truesize, p - buf, len); if (unlikely(!skb)) -- cgit v1.2.3