| Message ID | 1441958516-21107-1-git-send-email-jasowang@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Fri, 11 Sep 2015 16:01:56 +0800 Jason Wang <jasowang@redhat.com> wrote: > After commit 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make > features 64bit wide"). Device's guest_features was actually set after > vdc->load(). This breaks the assumption that device specific load() > function can check guest_features. For virtio-net, self announcement > and guest offloads won't work after migration. > > Fixing this by defer them to virtio_net_load() where guest_features > were guaranteed to be set. Other virtio devices looks fine. > > Fixes: 019a3edbb25f1571e876f8af1ce4c55412939e5d > ("virtio: make features 64bit wide") > Cc: qemu-stable@nongnu.org > Cc: Gerd Hoffmann <kraxel@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > hw/net/virtio-net.c | 40 +++++++++++++++++++++++----------------- > 1 file changed, 23 insertions(+), 17 deletions(-) Migration support for virtio is really a twisty maze, it's easy to make mistakes like that :( Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
On Fri, 11 Sep 2015 16:01:56 +0800 Jason Wang <jasowang@redhat.com> wrote: > After commit 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make > features 64bit wide"). Device's guest_features was actually set after > vdc->load(). This breaks the assumption that device specific load() Yeah... subsections are loaded after the device specific state... > function can check guest_features. For virtio-net, self announcement > and guest offloads won't work after migration. > > Fixing this by defer them to virtio_net_load() where guest_features > were guaranteed to be set. Other virtio devices looks fine. > > Fixes: 019a3edbb25f1571e876f8af1ce4c55412939e5d > ("virtio: make features 64bit wide") > Cc: qemu-stable@nongnu.org > Cc: Gerd Hoffmann <kraxel@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > hw/net/virtio-net.c | 40 +++++++++++++++++++++++----------------- > 1 file changed, 23 insertions(+), 17 deletions(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index f72eebf..2775e6a 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -1458,11 +1458,33 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) > { > VirtIONet *n = opaque; > VirtIODevice *vdev = VIRTIO_DEVICE(n); > + int ret; > > if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION) > return -EINVAL; > > - return virtio_load(vdev, f, version_id); > + ret = virtio_load(vdev, f, version_id); > + if (ret) { > + return ret; > + } > + > + if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { > + n->curr_guest_offloads = qemu_get_be64(f); > + } else { > + n->curr_guest_offloads = virtio_net_supported_guest_offloads(n); > + } > + > + if (peer_has_vnet_hdr(n)) { > + virtio_net_apply_guest_offloads(n); > + } > + > + if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) && > + virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) { > + n->announce_counter = SELF_ANNOUNCE_ROUNDS; > + timer_mod(n->announce_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL)); > + } > + > + return 0; > } > > static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, > @@ -1559,16 +1581,6 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, > } > } > > - if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { > - n->curr_guest_offloads = qemu_get_be64(f); > - } else { > - n->curr_guest_offloads = virtio_net_supported_guest_offloads(n); > - } > - > - if (peer_has_vnet_hdr(n)) { > - virtio_net_apply_guest_offloads(n); > - } > - > virtio_net_set_queues(n); > > /* Find the first multicast entry in the saved MAC filter */ > @@ -1586,12 +1598,6 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, > qemu_get_subqueue(n->nic, i)->link_down = link_down; > } > > - if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) && > - virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) { > - n->announce_counter = SELF_ANNOUNCE_ROUNDS; > - timer_mod(n->announce_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL)); > - } > - > return 0; > } >
On Fri, 11 Sep 2015 10:30:21 +0200 Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > On Fri, 11 Sep 2015 16:01:56 +0800 > Jason Wang <jasowang@redhat.com> wrote: > > > After commit 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make > > features 64bit wide"). Device's guest_features was actually set after > > vdc->load(). This breaks the assumption that device specific load() > > function can check guest_features. For virtio-net, self announcement > > and guest offloads won't work after migration. > > > > Fixing this by defer them to virtio_net_load() where guest_features > > were guaranteed to be set. Other virtio devices looks fine. > > > > Fixes: 019a3edbb25f1571e876f8af1ce4c55412939e5d > > ("virtio: make features 64bit wide") > > Cc: qemu-stable@nongnu.org > > Cc: Gerd Hoffmann <kraxel@redhat.com> > > Signed-off-by: Jason Wang <jasowang@redhat.com> > > --- > > hw/net/virtio-net.c | 40 +++++++++++++++++++++++----------------- > > 1 file changed, 23 insertions(+), 17 deletions(-) > > Migration support for virtio is really a twisty maze, it's easy to make > mistakes like that :( > We have the very same problem with @device_endian which is also streamed in a subsection. To prevent early usage on the load path, we set @device_endian to a poisoned value that triggers assert() in the virtio_is_big_endian() helper. Should this logic be generalized ?
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index f72eebf..2775e6a 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1458,11 +1458,33 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) { VirtIONet *n = opaque; VirtIODevice *vdev = VIRTIO_DEVICE(n); + int ret; if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION) return -EINVAL; - return virtio_load(vdev, f, version_id); + ret = virtio_load(vdev, f, version_id); + if (ret) { + return ret; + } + + if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { + n->curr_guest_offloads = qemu_get_be64(f); + } else { + n->curr_guest_offloads = virtio_net_supported_guest_offloads(n); + } + + if (peer_has_vnet_hdr(n)) { + virtio_net_apply_guest_offloads(n); + } + + if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) && + virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) { + n->announce_counter = SELF_ANNOUNCE_ROUNDS; + timer_mod(n->announce_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL)); + } + + return 0; } static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, @@ -1559,16 +1581,6 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, } } - if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { - n->curr_guest_offloads = qemu_get_be64(f); - } else { - n->curr_guest_offloads = virtio_net_supported_guest_offloads(n); - } - - if (peer_has_vnet_hdr(n)) { - virtio_net_apply_guest_offloads(n); - } - virtio_net_set_queues(n); /* Find the first multicast entry in the saved MAC filter */ @@ -1586,12 +1598,6 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, qemu_get_subqueue(n->nic, i)->link_down = link_down; } - if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) && - virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) { - n->announce_counter = SELF_ANNOUNCE_ROUNDS; - timer_mod(n->announce_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL)); - } - return 0; }
After commit 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make features 64bit wide"). Device's guest_features was actually set after vdc->load(). This breaks the assumption that device specific load() function can check guest_features. For virtio-net, self announcement and guest offloads won't work after migration. Fixing this by defer them to virtio_net_load() where guest_features were guaranteed to be set. Other virtio devices looks fine. Fixes: 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make features 64bit wide") Cc: qemu-stable@nongnu.org Cc: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- hw/net/virtio-net.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-)