@@ -32,6 +32,7 @@ typedef struct VirtIONet
VLANClientState *vc;
QEMUTimer *tx_timer;
int tx_timer_active;
+ uint32_t has_vnet_hdr;
struct {
VirtQueueElement elem;
ssize_t len;
@@ -120,8 +121,22 @@ static void virtio_net_reset(VirtIODevice *vdev)
memset(n->vlans, 0, MAX_VLAN >> 3);
}
+static int peer_has_vnet_hdr(VirtIONet *n)
+{
+ if (!n->vc->peer)
+ return 0;
+
+ if (n->vc->peer->type != NET_CLIENT_TYPE_TAP)
+ return 0;
+
+ n->has_vnet_hdr = tap_has_vnet_hdr(n->vc->peer);
+
+ return n->has_vnet_hdr;
+}
+
static uint32_t virtio_net_get_features(VirtIODevice *vdev)
{
+ VirtIONet *n = to_virtio_net(vdev);
uint32_t features = (1 << VIRTIO_NET_F_MAC) |
(1 << VIRTIO_NET_F_MRG_RXBUF) |
(1 << VIRTIO_NET_F_STATUS) |
@@ -130,6 +145,15 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev)
(1 << VIRTIO_NET_F_CTRL_VLAN) |
(1 << VIRTIO_NET_F_CTRL_RX_EXTRA);
+ if (peer_has_vnet_hdr(n)) {
+ tap_using_vnet_hdr(n->vc->peer, 1);
+
+ features |= (1 << VIRTIO_NET_F_CSUM);
+ features |= (1 << VIRTIO_NET_F_HOST_TSO4);
+ features |= (1 << VIRTIO_NET_F_HOST_TSO6);
+ features |= (1 << VIRTIO_NET_F_HOST_ECN);
+ }
+
return features;
}
@@ -359,6 +383,11 @@ static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
hdr->flags = 0;
hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
+ if (n->has_vnet_hdr) {
+ memcpy(hdr, buf, sizeof(*hdr));
+ offset = sizeof(*hdr);
+ }
+
/* We only ever receive a struct virtio_net_hdr from the tapfd,
* but we may be passing along a larger header to the guest.
*/
@@ -378,6 +407,10 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
if (n->promisc)
return 1;
+ if (n->has_vnet_hdr) {
+ ptr += sizeof(struct virtio_net_hdr);
+ }
+
if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
@@ -510,7 +543,6 @@ static void virtio_net_tx_complete(VLANClientState *vc, ssize_t len)
static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
{
VirtQueueElement elem;
- int has_vnet_hdr = 0;
if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
return;
@@ -537,7 +569,7 @@ static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
}
/* ignore the header if GSO is not supported */
- if (!has_vnet_hdr) {
+ if (!n->has_vnet_hdr) {
out_num--;
out_sg++;
len += hdr_len;
@@ -610,7 +642,7 @@ static void virtio_net_save(QEMUFile *f, void *opaque)
qemu_put_be32(f, n->mac_table.in_use);
qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
- qemu_put_be32(f, 0); /* vnet-hdr placeholder */
+ qemu_put_be32(f, n->has_vnet_hdr);
qemu_put_byte(f, n->mac_table.multi_overflow);
qemu_put_byte(f, n->mac_table.uni_overflow);
qemu_put_byte(f, n->alluni);
@@ -662,10 +694,15 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
if (version_id >= 6)
qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
- if (version_id >= 7 && qemu_get_be32(f)) {
- fprintf(stderr,
- "virtio-net: saved image requires vnet header support\n");
- exit(1);
+ if (version_id >= 7) {
+ if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
+ qemu_error("virtio-net: saved image requires vnet_hdr=on\n");
+ return -1;
+ }
+
+ if (n->has_vnet_hdr) {
+ tap_using_vnet_hdr(n->vc->peer, 1);
+ }
}
if (version_id >= 9) {
With '-netdev tap,id=foo -nic model=virtio,netdev=foo' virtio-net can detect that its peer (i.e. the tap backend) supports vnet headers and advertise to the guest that it can send packets with partial checksums and/or TSO packets. One complication is that if we're migrating and the source host supports IFF_VNET_HDR but the destination host doesn't, we can't then stop the guest from using those features. In this scenario, we just fail the migration. [v2: - add has_vnet_hdr uint32_t field for ease of vmstate conversion - use qemu_error() ] Signed-off-by: Mark McLoughlin <markmc@redhat.com> --- hw/virtio-net.c | 51 ++++++++++++++++++++++++++++++++++++++++++++------- 1 files changed, 44 insertions(+), 7 deletions(-)