Re: [PATCH RFC v2 1/2] tun: support rx-tstamp
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2026-02-01 21:00:51
Also in:
lkml, virtualization
Steffen Trumtrar wrote:
quoted hunk ↗ jump to hunk
Demonstrate support for new virtio-net features VIRTIO_NET_HDR_F_TSTAMP This is not intended to be merged. A full feature test also requires a patched qemu binary that knows these features and negotiates correct vnet_hdr_sz in virtio_net_set_mrg_rx_bufs. See https://github.com/strumtrar/qemu/tree/v10.2.0/virtio-rx-stamps Not-yet-signed-off-by: Steffen Trumtrar [off-list ref] --- drivers/net/tun.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-)diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 8192740357a09..aa988a9c4bc99 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c@@ -2065,23 +2065,29 @@ static ssize_t tun_put_user(struct tun_struct *tun, } if (vnet_hdr_sz) { - struct virtio_net_hdr_v1_hash_tunnel hdr; - struct virtio_net_hdr *gso; + struct virtio_net_hdr_v1_hash_tunnel_ts hdr;
This patch refers to a struct that does not exist yet, so this cannot compile?
+
+ memset(&hdr, 0, sizeof(hdr));
ret = tun_vnet_hdr_tnl_from_skb(tun->flags, tun->dev, skb,
- &hdr);
+ (struct virtio_net_hdr_v1_hash_tunnel *)&hdr);
if (ret)
return ret;
- /*
- * Drop the packet if the configured header size is too small
- * WRT the enabled offloads.
- */
- gso = (struct virtio_net_hdr *)&hdr;
- ret = __tun_vnet_hdr_put(vnet_hdr_sz, tun->dev->features,
- iter, gso);
- if (ret)
- return ret;
+ if (vnet_hdr_sz >= sizeof(struct virtio_net_hdr_v1_hash_tunnel_ts)) {
+ __le64 tstamp = cpu_to_le64(ktime_get_ns());
+
+ hdr.tstamp_0 = (tstamp & 0x000000000000ffffULL) >> 0;
+ hdr.tstamp_1 = (tstamp & 0x00000000ffff0000ULL) >> 16;
+ hdr.tstamp_2 = (tstamp & 0x0000ffff00000000ULL) >> 32;
+ hdr.tstamp_3 = (tstamp & 0xffff000000000000ULL) >> 48;
+ }
+
+ if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
+ return -EINVAL;
+
+ if (unlikely(copy_to_iter(&hdr, vnet_hdr_sz, iter) != vnet_hdr_sz))
+ return -EFAULT;
}
if (vlan_hlen) {
--
2.52.0