On 2018年04月02日 21:40, Vladislav Yasevich wrote:
To support SCTP checksum offloading, we need to add a new feature
to virtio_net, so we can negotiate support between the hypervisor
and the guest.
The signalling to the guest that an alternate checksum needs to
be used is done via a new flag in the virtio_net_hdr. If the
flag is set, the host will know to perform an alternate checksum
calculation, which right now is only CRC32c.
Signed-off-by: Vladislav Yasevich <vyasevic@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 11 ++++++++---
include/linux/virtio_net.h | 6 ++++++
include/uapi/linux/virtio_net.h | 2 ++
3 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7b187ec..b601294 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2724,9 +2724,14 @@ static int virtnet_probe(struct virtio_device *vdev)
/* Do we support "hardware" checksums? */
if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
/* This opens up the world of extra features. */
- dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
+ netdev_features_t sctp = 0;
+
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_SCTP_CSUM))
+ sctp |= NETIF_F_SCTP_CRC;
+
+ dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG | sctp;
if (csum)
- dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
+ dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG | sctp;
if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
dev->hw_features |= NETIF_F_TSO
@@ -2952,7 +2957,7 @@ static struct virtio_device_id id_table[] = {
};
#define VIRTNET_FEATURES \
- VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
+ VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, VIRTIO_NET_F_SCTP_CSUM, \
It looks to me _F_SCTP_CSUM implies the ability of both device and
driver. Do we still need the flexibility like csum to differ guest/host
ability like e.g _F_GUEST_SCTP_CSUM?
Thanks
VIRTIO_NET_F_MAC, \
VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index f144216..2e7a64a 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -39,6 +39,9 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
if (!skb_partial_csum_set(skb, start, off))
return -EINVAL;
+
+ if (hdr->flags & VIRTIO_NET_HDR_F_CSUM_NOT_INET)
+ skb->csum_not_inet = 1;
}
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
@@ -96,6 +99,9 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
} /* else everything is zero */
+ if (skb->csum_not_inet)
+ hdr->flags &= VIRTIO_NET_HDR_F_CSUM_NOT_INET;
+
return 0;
}
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 5de6ed3..3f279c8 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -36,6 +36,7 @@
#define VIRTIO_NET_F_GUEST_CSUM 1 /* Guest handles pkts w/ partial csum */
#define VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2 /* Dynamic offload configuration. */
#define VIRTIO_NET_F_MTU 3 /* Initial MTU advice */
+#define VIRTIO_NET_F_SCTP_CSUM 4 /* SCTP checksum offload support */
#define VIRTIO_NET_F_MAC 5 /* Host has given MAC address. */
#define VIRTIO_NET_F_GUEST_TSO4 7 /* Guest can handle TSOv4 in. */
#define VIRTIO_NET_F_GUEST_TSO6 8 /* Guest can handle TSOv6 in. */
@@ -101,6 +102,7 @@ struct virtio_net_config {
struct virtio_net_hdr_v1 {
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 /* Use csum_start, csum_offset */
#define VIRTIO_NET_HDR_F_DATA_VALID 2 /* Csum is valid */
+#define VIRTIO_NET_HDR_F_CSUM_NOT_INET 4 /* Checksum is not inet */
__u8 flags;
#define VIRTIO_NET_HDR_GSO_NONE 0 /* Not a GSO frame */
#define VIRTIO_NET_HDR_GSO_TCPV4 1 /* GSO frame, IPv4 TCP (TSO) */
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