This patch enables the ability to pass the rxhash value to guest
through vnet_hdr. This is useful for guest when it wants to cooperate
with virtual device to steer a flow to dedicated guest cpu.
This feature is negotiated through VIRTIO_NET_F_GUEST_RXHASH.
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/net/macvtap.c | 10 ++++++----
drivers/net/tun.c | 44 +++++++++++++++++++++++++-------------------
drivers/net/virtio_net.c | 26 ++++++++++++++++++++++----
drivers/vhost/net.c | 10 +++++++---
drivers/vhost/vhost.h | 5 +++--
include/linux/if_tun.h | 1 +
include/linux/virtio_net.h | 10 +++++++++-
7 files changed, 73 insertions(+), 33 deletions(-)
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 7c88d13..504c745 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -760,16 +760,17 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
int vnet_hdr_len = 0;
if (q->flags & IFF_VNET_HDR) {
- struct virtio_net_hdr vnet_hdr;
+ struct virtio_net_hdr_rxhash vnet_hdr;
vnet_hdr_len = q->vnet_hdr_sz;
if ((len -= vnet_hdr_len) < 0)
return -EINVAL;
- ret = macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
+ ret = macvtap_skb_to_vnet_hdr(skb, &vnet_hdr.hdr.hdr);
if (ret)
return ret;
- if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
+ vnet_hdr.rxhash = skb->rxhash;
+ if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, q->vnet_hdr_sz))
return -EFAULT;
}
@@ -890,7 +891,8 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
return ret;
case TUNGETFEATURES:
- if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR, up))
+ if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR | IFF_RXHASH,
+ up))
return -EFAULT;
return 0;
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index afb11d1..7d22b4b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -869,49 +869,55 @@ static ssize_t tun_put_user(struct tun_file *tfile,
}
if (tfile->flags & TUN_VNET_HDR) {
- struct virtio_net_hdr gso = { 0 }; /* no info leak */
- if ((len -= tfile->vnet_hdr_sz) < 0)
+ struct virtio_net_hdr_rxhash hdr;
+ struct virtio_net_hdr *gso = (struct virtio_net_hdr *)&hdr;
+
+ if ((len -= tfile->vnet_hdr_sz) < 0 ||
+ tfile->vnet_hdr_sz > sizeof(struct virtio_net_hdr_rxhash))
return -EINVAL;
+ memset(&hdr, 0, sizeof(hdr));
if (skb_is_gso(skb)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
/* This is a hint as to how much should be linear. */
- gso.hdr_len = skb_headlen(skb);
- gso.gso_size = sinfo->gso_size;
+ gso->hdr_len = skb_headlen(skb);
+ gso->gso_size = sinfo->gso_size;
if (sinfo->gso_type & SKB_GSO_TCPV4)
- gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+ gso->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (sinfo->gso_type & SKB_GSO_TCPV6)
- gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+ gso->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
else if (sinfo->gso_type & SKB_GSO_UDP)
- gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
+ gso->gso_type = VIRTIO_NET_HDR_GSO_UDP;
else {
pr_err("unexpected GSO type: "
"0x%x, gso_size %d, hdr_len %d\n",
- sinfo->gso_type, gso.gso_size,
- gso.hdr_len);
+ sinfo->gso_type, gso->gso_size,
+ gso->hdr_len);
print_hex_dump(KERN_ERR, "tun: ",
DUMP_PREFIX_NONE,
16, 1, skb->head,
- min((int)gso.hdr_len, 64), true);
+ min((int)gso->hdr_len, 64),
+ true);
WARN_ON_ONCE(1);
return -EINVAL;
}
if (sinfo->gso_type & SKB_GSO_TCP_ECN)
- gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
+ gso->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else
- gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
+ gso->gso_type = VIRTIO_NET_HDR_GSO_NONE;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
- gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
- gso.csum_start = skb_checksum_start_offset(skb);
- gso.csum_offset = skb->csum_offset;
+ gso->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+ gso->csum_start = skb_checksum_start_offset(skb);
+ gso->csum_offset = skb->csum_offset;
} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
- gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
+ gso->flags = VIRTIO_NET_HDR_F_DATA_VALID;
} /* else everything is zero */
- if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
- sizeof(gso))))
+ hdr.rxhash = skb_get_rxhash(skb);
+ if (unlikely(memcpy_toiovecend(iv, (void *)&hdr, total,
+ tfile->vnet_hdr_sz)))
return -EFAULT;
total += tfile->vnet_hdr_sz;
}
@@ -1358,7 +1364,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
* This is needed because we never checked for invalid flags on
* TUNSETIFF. */
return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
- IFF_VNET_HDR | IFF_MULTI_QUEUE,
+ IFF_VNET_HDR | IFF_MULTI_QUEUE | IFF_RXHASH,
(unsigned int __user*)argp);
}
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 157ee63..0d871f8 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -107,12 +107,16 @@ struct virtnet_info {
/* Host will merge rx buffers for big packets (shake it! shake it!) */
bool mergeable_rx_bufs;
+
+ /* Host will pass rxhash to us. */
+ bool has_rxhash;
};
struct skb_vnet_hdr {
union {
struct virtio_net_hdr hdr;
struct virtio_net_hdr_mrg_rxbuf mhdr;
+ struct virtio_net_hdr_rxhash rhdr;
};
unsigned int num_sg;
};
@@ -205,7 +209,10 @@ static struct sk_buff *page_to_skb(struct receive_queue *rq,
hdr = skb_vnet_hdr(skb);
if (vi->mergeable_rx_bufs) {
- hdr_len = sizeof hdr->mhdr;
+ if (vi->has_rxhash)
+ hdr_len = sizeof hdr->rhdr;
+ else
+ hdr_len = sizeof hdr->mhdr;
offset = hdr_len;
} else {
hdr_len = sizeof hdr->hdr;
@@ -376,6 +383,9 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
skb_shinfo(skb)->gso_segs = 0;
}
+ if (vi->has_rxhash)
+ skb->rxhash = hdr->rhdr.rxhash;
+
netif_receive_skb(skb);
return;
@@ -645,9 +655,12 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb,
hdr->mhdr.num_buffers = 0;
/* Encode metadata header at front. */
- if (vi->mergeable_rx_bufs)
- sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
- else
+ if (vi->mergeable_rx_bufs) {
+ if (vi->has_rxhash)
+ sg_set_buf(sg, &hdr->rhdr, sizeof hdr->rhdr);
+ else
+ sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
+ } else
sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
hdr->num_sg = skb_to_sgvec(skb, sg + 1, 0, skb->len) + 1;
@@ -1338,8 +1351,12 @@ static int virtnet_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_RXHASH))
+ vi->has_rxhash = true;
+
/* Allocate/initialize the rx/tx queues, and invoke find_vqs */
err = virtnet_setup_vqs(vi);
+
if (err)
goto free_netdev;
@@ -1436,6 +1453,7 @@ static unsigned int features[] = {
VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, VIRTIO_NET_F_MULTIQUEUE,
+ VIRTIO_NET_F_GUEST_RXHASH,
};
static struct virtio_driver virtio_net_driver = {
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 882a51f..b2d6548 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -768,9 +768,13 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
size_t vhost_hlen, sock_hlen, hdr_len;
int i;
- hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
- sizeof(struct virtio_net_hdr_mrg_rxbuf) :
- sizeof(struct virtio_net_hdr);
+ if (features & (1 << VIRTIO_NET_F_MRG_RXBUF))
+ hdr_len = (features & (1 << VIRTIO_NET_F_GUEST_RXHASH)) ?
+ sizeof(struct virtio_net_hdr_rxhash) :
+ sizeof(struct virtio_net_hdr_mrg_rxbuf);
+ else
+ hdr_len = sizeof(struct virtio_net_hdr);
+
if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
/* vhost provides vnet_hdr */
vhost_hlen = hdr_len;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index a801e28..4ad2d5f 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -115,7 +115,7 @@ struct vhost_virtqueue {
/* hdr is used to store the virtio header.
* Since each iovec has >= 1 byte length, we never need more than
* header length entries to store the header. */
- struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
+ struct iovec hdr[sizeof(struct virtio_net_hdr_rxhash)];
struct iovec *indirect;
size_t vhost_hlen;
size_t sock_hlen;
@@ -203,7 +203,8 @@ enum {
(1ULL << VIRTIO_RING_F_EVENT_IDX) |
(1ULL << VHOST_F_LOG_ALL) |
(1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
- (1ULL << VIRTIO_NET_F_MRG_RXBUF),
+ (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
+ (1ULL << VIRTIO_NET_F_GUEST_RXHASH) ,
};
static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index d3f24d8..a1f6f3f 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -66,6 +66,7 @@
#define IFF_VNET_HDR 0x4000
#define IFF_TUN_EXCL 0x8000
#define IFF_MULTI_QUEUE 0x0100
+#define IFF_RXHASH 0x0200
/* Features for GSO (TUNSETOFFLOAD). */
#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index c92b83f..2291317 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -50,6 +50,7 @@
#define VIRTIO_NET_F_CTRL_VLAN 19 /* Control channel VLAN filtering */
#define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */
#define VIRTIO_NET_F_MULTIQUEUE 21 /* Device supports multiple TXQ/RXQ */
+#define VIRTIO_NET_F_GUEST_RXHASH 22 /* Guest can receive rxhash */
#define VIRTIO_NET_S_LINK_UP 1 /* Link is up */
@@ -63,7 +64,7 @@ struct virtio_net_config {
} __attribute__((packed));
/* This is the first element of the scatter-gather list. If you don't
- * specify GSO or CSUM features, you can simply ignore the header. */
+ * specify GSO, CSUM or HASH features, you can simply ignore the header. */
struct virtio_net_hdr {
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 // Use csum_start, csum_offset
#define VIRTIO_NET_HDR_F_DATA_VALID 2 // Csum is valid
@@ -87,6 +88,13 @@ struct virtio_net_hdr_mrg_rxbuf {
__u16 num_buffers; /* Number of merged rx buffers */
};
+/* This is the version of the header to use when GUEST_RXHASH
+ * feature has been negotiated. */
+struct virtio_net_hdr_rxhash {
+ struct virtio_net_hdr_mrg_rxbuf hdr;
+ __u32 rxhash;
+};
+
/*
* Control virtqueue data structures
*
--
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