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Message-ID: <6838211b8b864c757204a2bfd1ad3ffc7aa42e52.1725616135.git.mst@redhat.com>
Date: Fri, 6 Sep 2024 05:52:21 -0400
From: "Michael S. Tsirkin" <mst@...hat.com>
To: linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Cc: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
Jason Wang <jasowang@...hat.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
virtualization@...ts.linux.dev, Si-Wei Liu <si-wei.liu@...cle.com>,
Darren Kenny <darren.kenny@...cle.com>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>,
Eugenio PĂ©rez <eperezma@...hat.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Jesper Dangaard Brouer <hawk@...nel.org>,
John Fastabend <john.fastabend@...il.com>, bpf@...r.kernel.org
Subject: [RFC PATCH v2 2/7] Revert "virtio_net: xsk: rx: support recv small
mode"
This reverts commit a4e7ba7027012f009f22a68bcfde670f9298d3a4.
leads to crashes with no ACCESS_PLATFORM when
sysctl net.core.high_order_alloc_disable=1
Cc: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
Reported-by: Si-Wei Liu <si-wei.liu@...cle.com>
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
---
drivers/net/virtio_net.c | 198 ++++-----------------------------------
1 file changed, 19 insertions(+), 179 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 15e202dd6964..041c483a06c5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -498,12 +498,6 @@ struct virtio_net_common_hdr {
};
static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
-static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
- struct net_device *dev,
- unsigned int *xdp_xmit,
- struct virtnet_rq_stats *stats);
-static void virtnet_receive_done(struct virtnet_info *vi, struct receive_queue *rq,
- struct sk_buff *skb, u8 flags);
static bool is_xdp_frame(void *ptr)
{
@@ -1068,124 +1062,6 @@ static void sg_fill_dma(struct scatterlist *sg, dma_addr_t addr, u32 len)
sg->length = len;
}
-static struct xdp_buff *buf_to_xdp(struct virtnet_info *vi,
- struct receive_queue *rq, void *buf, u32 len)
-{
- struct xdp_buff *xdp;
- u32 bufsize;
-
- xdp = (struct xdp_buff *)buf;
-
- bufsize = xsk_pool_get_rx_frame_size(rq->xsk_pool) + vi->hdr_len;
-
- if (unlikely(len > bufsize)) {
- pr_debug("%s: rx error: len %u exceeds truesize %u\n",
- vi->dev->name, len, bufsize);
- DEV_STATS_INC(vi->dev, rx_length_errors);
- xsk_buff_free(xdp);
- return NULL;
- }
-
- xsk_buff_set_size(xdp, len);
- xsk_buff_dma_sync_for_cpu(xdp);
-
- return xdp;
-}
-
-static struct sk_buff *xsk_construct_skb(struct receive_queue *rq,
- struct xdp_buff *xdp)
-{
- unsigned int metasize = xdp->data - xdp->data_meta;
- struct sk_buff *skb;
- unsigned int size;
-
- size = xdp->data_end - xdp->data_hard_start;
- skb = napi_alloc_skb(&rq->napi, size);
- if (unlikely(!skb)) {
- xsk_buff_free(xdp);
- return NULL;
- }
-
- skb_reserve(skb, xdp->data_meta - xdp->data_hard_start);
-
- size = xdp->data_end - xdp->data_meta;
- memcpy(__skb_put(skb, size), xdp->data_meta, size);
-
- if (metasize) {
- __skb_pull(skb, metasize);
- skb_metadata_set(skb, metasize);
- }
-
- xsk_buff_free(xdp);
-
- return skb;
-}
-
-static struct sk_buff *virtnet_receive_xsk_small(struct net_device *dev, struct virtnet_info *vi,
- struct receive_queue *rq, struct xdp_buff *xdp,
- unsigned int *xdp_xmit,
- struct virtnet_rq_stats *stats)
-{
- struct bpf_prog *prog;
- u32 ret;
-
- ret = XDP_PASS;
- rcu_read_lock();
- prog = rcu_dereference(rq->xdp_prog);
- if (prog)
- ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats);
- rcu_read_unlock();
-
- switch (ret) {
- case XDP_PASS:
- return xsk_construct_skb(rq, xdp);
-
- case XDP_TX:
- case XDP_REDIRECT:
- return NULL;
-
- default:
- /* drop packet */
- xsk_buff_free(xdp);
- u64_stats_inc(&stats->drops);
- return NULL;
- }
-}
-
-static void virtnet_receive_xsk_buf(struct virtnet_info *vi, struct receive_queue *rq,
- void *buf, u32 len,
- unsigned int *xdp_xmit,
- struct virtnet_rq_stats *stats)
-{
- struct net_device *dev = vi->dev;
- struct sk_buff *skb = NULL;
- struct xdp_buff *xdp;
- u8 flags;
-
- len -= vi->hdr_len;
-
- u64_stats_add(&stats->bytes, len);
-
- xdp = buf_to_xdp(vi, rq, buf, len);
- if (!xdp)
- return;
-
- if (unlikely(len < ETH_HLEN)) {
- pr_debug("%s: short packet %i\n", dev->name, len);
- DEV_STATS_INC(dev, rx_length_errors);
- xsk_buff_free(xdp);
- return;
- }
-
- flags = ((struct virtio_net_common_hdr *)(xdp->data - vi->hdr_len))->hdr.flags;
-
- if (!vi->mergeable_rx_bufs)
- skb = virtnet_receive_xsk_small(dev, vi, rq, xdp, xdp_xmit, stats);
-
- if (skb)
- virtnet_receive_done(vi, rq, skb, flags);
-}
-
static int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct receive_queue *rq,
struct xsk_buff_pool *pool, gfp_t gfp)
{
@@ -2516,67 +2392,31 @@ static void refill_work(struct work_struct *work)
}
}
-static int virtnet_receive_xsk_bufs(struct virtnet_info *vi,
- struct receive_queue *rq,
- int budget,
- unsigned int *xdp_xmit,
- struct virtnet_rq_stats *stats)
-{
- unsigned int len;
- int packets = 0;
- void *buf;
-
- while (packets < budget) {
- buf = virtqueue_get_buf(rq->vq, &len);
- if (!buf)
- break;
-
- virtnet_receive_xsk_buf(vi, rq, buf, len, xdp_xmit, stats);
- packets++;
- }
-
- return packets;
-}
-
-static int virtnet_receive_packets(struct virtnet_info *vi,
- struct receive_queue *rq,
- int budget,
- unsigned int *xdp_xmit,
- struct virtnet_rq_stats *stats)
-{
- unsigned int len;
- int packets = 0;
- void *buf;
-
- if (!vi->big_packets || vi->mergeable_rx_bufs) {
- void *ctx;
- while (packets < budget &&
- (buf = virtnet_rq_get_buf(rq, &len, &ctx))) {
- receive_buf(vi, rq, buf, len, ctx, xdp_xmit, stats);
- packets++;
- }
- } else {
- while (packets < budget &&
- (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
- receive_buf(vi, rq, buf, len, NULL, xdp_xmit, stats);
- packets++;
- }
- }
-
- return packets;
-}
-
static int virtnet_receive(struct receive_queue *rq, int budget,
unsigned int *xdp_xmit)
{
struct virtnet_info *vi = rq->vq->vdev->priv;
struct virtnet_rq_stats stats = {};
- int i, packets;
+ unsigned int len;
+ int packets = 0;
+ void *buf;
+ int i;
- if (rq->xsk_pool)
- packets = virtnet_receive_xsk_bufs(vi, rq, budget, xdp_xmit, &stats);
- else
- packets = virtnet_receive_packets(vi, rq, budget, xdp_xmit, &stats);
+ if (!vi->big_packets || vi->mergeable_rx_bufs) {
+ void *ctx;
+
+ while (packets < budget &&
+ (buf = virtnet_rq_get_buf(rq, &len, &ctx))) {
+ receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
+ packets++;
+ }
+ } else {
+ while (packets < budget &&
+ (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
+ receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
+ packets++;
+ }
+ }
if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
--
MST
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