We were failing to save two important pieces of state:
1) Whether the guest will supply us rx buffers using the
new mergeable format; this caused the migrated guest
to crash with "virtio-net header not in first element"
2) Whether the tx/rx buffers we exchange with the tap
code should include a virtio_net_hdr header; this
caused the migrated guest to receive garbage packets
because the tap code was stripping away the header
and virtio_net was interpreting packet data as the
virtio_net header
With these fixes a guest using mergeable rx buffers and
GSO passes a simple "ping while migrating" test.
The mergeable rx buffers part has been sent upstream to
qemu-devel, but the GSO part is KVM specific.
Signed-off-by: Mark McLoughlin <[email protected]>
---
qemu/hw/virtio-net.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/qemu/hw/virtio-net.c b/qemu/hw/virtio-net.c
index ef8f591..e47a0a4 100644
--- a/qemu/hw/virtio-net.c
+++ b/qemu/hw/virtio-net.c
@@ -360,6 +360,11 @@ static void virtio_net_save(QEMUFile *f, void *opaque)
qemu_put_buffer(f, n->mac, 6);
qemu_put_be32(f, n->tx_timer_active);
+ qemu_put_be32(f, n->mergeable_rx_bufs);
+
+#ifdef TAP_VNET_HDR
+ qemu_put_be32(f, tap_has_vnet_hdr(n->vc->vlan->first_client));
+#endif
}
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
@@ -373,6 +378,12 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int
version_id)
qemu_get_buffer(f, n->mac, 6);
n->tx_timer_active = qemu_get_be32(f);
+ n->mergeable_rx_bufs = qemu_get_be32(f);
+
+#ifdef TAP_VNET_HDR
+ if (qemu_get_be32(f))
+ tap_using_vnet_hdr(n->vc->vlan->first_client, 1);
+#endif
if (n->tx_timer_active) {
qemu_mod_timer(n->tx_timer,
--
1.6.0.6
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