If we tell the guest we support UFO and then migrate to host which
doesn't support it, we will find ourselves in grave difficulties.
Prevent this scenario by adding a flag to virtio-net's savevm format
which indicates whether the device requires host UFO support.
[v2:
- add has_ufo uint8_t field for ease of vmstate conversion
- use qemu_error()
]
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Enable UFO on the host tap device if supported and allow setting UFO
on virtio-net in the guest.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
With the latest GSO/csum offload patches, any guest using an unpatched version
of dhclient (any Ubuntu guest, for instance), will no longer be able to get
a DHCP address.
dhclient is actually at fault here. It uses AF_PACKET to receive DHCP responses
but does not check auxdata to see if the packet has a valid csum. This causes
it to throw out the DHCP responses it gets from the virtio interface as there
is not a valid checksum.
Fedora has carried a patch to fix their dhclient (it's needed for Xen too) but
this patch has not made it into a release of dhclient. AFAIK, the patch is in
the dhclient CVS but I cannot confirm since their CVS is not public.
This patch, suggested by Rusty, looks for UDP packets (of a normal MTU) and
explicitly adds a checksum to them if they are missing one.
This allows unpatched dhclients to continue to work without needing to update
the guest kernels.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We query the guest's feature set to see if it supports offload and,
if so, we enable those features on the tap interface.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Trivial patch to allow supplying a receive_raw function.
A future cleanup should combine this function pointer parameters into a
table.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This is so as to allow APIs which operate on specific client types
without having to add a function table entry which is only implemented
by a single client type.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Errors are still directly printed, as we are only converting
regular output.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Just sent <anything> as a buffer. We put the pointer and the size
code does the rest.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
For a start bypp is not changed after vmsvga_reset() and it depends on depth
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
It don't compile. And the trivial fixes (change vga.foo field to foo field
don't work either. No output
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
VMSTATE_SUB_ARRAY(..., start, num, ...) saves the num elems starting at
position start of the array
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
It allows to have 'things' in savevm format not backed in the device state
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This allows to define VMSTATE_SINGLE with VMSTATE_SINGLE_TEST
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
