On 2025/03/11 9:42, Jason Wang wrote:
On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki akihiko.odaki@daynix.com wrote:
On 2025/03/10 13:43, Jason Wang wrote:
On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki akihiko.odaki@daynix.com wrote:
VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no hash values (i.e., the hash_report member is always set to VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the underlying socket will be reported.
VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
Signed-off-by: Akihiko Odaki akihiko.odaki@daynix.com Tested-by: Lei Yang leiyang@redhat.com
drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 20 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -73,6 +73,7 @@ enum { VHOST_NET_FEATURES = VHOST_FEATURES | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
(1ULL << VIRTIO_NET_F_HASH_REPORT) | (1ULL << VIRTIO_F_ACCESS_PLATFORM) | (1ULL << VIRTIO_F_RING_RESET)@@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net) .msg_controllen = 0, .msg_flags = MSG_DONTWAIT, };
struct virtio_net_hdr hdr = {.flags = 0,.gso_type = VIRTIO_NET_HDR_GSO_NONE
struct virtio_net_hdr_v1_hash hdr = {.hdr = {.flags = 0,.gso_type = VIRTIO_NET_HDR_GSO_NONE} }; size_t total_len = 0; int err, mergeable;@@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net) bool set_num_buffers; struct socket *sock; struct iov_iter fixup;
__virtio16 num_buffers; int recv_pkts = 0; mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);@@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net) vhost_discard_vq_desc(vq, headcount); continue; }
hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount); /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ if (unlikely(vhost_hlen)) {
if (copy_to_iter(&hdr, sizeof(hdr),&fixup) != sizeof(hdr)) {
if (copy_to_iter(&hdr, vhost_hlen,&fixup) != vhost_hlen) { vq_err(vq, "Unable to write vnet_hdr " "at addr %p\n", vq->iov->iov_base); goto out;Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
Honestly, I'm not sure if it's too late to fix this.
There is nothing wrong with the current implementation.
Note that I meant the vhost_hlen part, and the current code is tricky.
The comment said:
""" /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ """
So it tries to only offer virtio_net_hdr even if vhost_hlen is the set to mrg_rxbuf len.
And this patch changes this behaviour.
mrg_rxbuf only adds the num_buffers field, which is always set for mrg_rxbuf.
The num_buffers was not set for VIRTIO_F_VERSION_1 in the past, but this was also fixed with commit a3b9c053d82a ("vhost/net: Set num_buffers for virtio 1.0")
So there is no behavioral change for existing features with this patch.
Regards, Akihiko Odaki
Thanks
The current implementation fills the header with zero except num_buffers, which it fills some real value. This functionality is working fine with VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report field, which also needs to be initialized with zero, so I'm making sure vhost_net will also initialize it.
Regards, Akihiko Odaki
Others look fine.
Thanks