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>
This API allows virtio-net to enable various offload features on a
tap interface - e.g. to tell the host kernel it can pass up partial
checksums to userspace.
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>
tap_receive_raw() always prepends a vnet header if IFF_VNET_HDR is
enabled.
tap_receive() only prepends when the a header is required but the NIC
doesn't supply one.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Use qemu_send_packet_raw to send gratuitous arp. This will ensure that
vnet header is handled properly.
Also, avoid sending the gratuitous packet to the guest. There doesn't
appear to be any reason for doing that and the code will currently just
crash if the NIC is not associated with a vlan.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
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>
In the case where a NIC and backend agree on a packet header format,
this API allows injecting packets which lack the agreed upon header.
We need this for sending our gratuitous ARP.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This allows for the addition of a raw flag, and leaves the way open
for other flags too.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
These lamely named functions allow virtio-net to query whether
IFF_VNET_HDR is enabled on a tap interface and inform the tap code
that virtio-net will supply packets with a vnet header.
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>
This allows people to disable the IFF_VNET_HDR flag, e.g. for debugging
purposes or if they know they may migrate the guest to a machine without
IFF_VNET_HDR support.
It also allows making the lack of IFF_VNET_HDR support an error
condition, e.g. in the case where a guest is being migrated from a host
which does support it.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Re-factor things so that there is only one call site for
net_tap_fd_init().
Two concerns about the QemuOpts usage here - firstly, we set the script
arguments to their default value and, secondly, we set the ifname value
to the name allocated by the kernel if none is supplied. Are we okay
with such things ending up in writeconfig output?
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
For now, we just add an empty header before writing and strip the header
after reading.
We really only want IFF_VNET_HDR when virtio_net is using it, but it
would significantly complicate matters to try and do that. There should
be little or no performance impact with always adding headers.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In future we will want to prepend a virtio_net header if the NIC didn't
supply one but IFF_VNET_HDR is enabled on the interface. This is most
easily achived by using writev() in all cases.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Making features dependent on the availability of newer versions if_tun.h
is going to get seriously clumsy, so let's just import the definitions
we need. It's only a small handful.
If and when we're comfortable depending on 2.6.30 headers, we can remove
this again.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Looks like these are just artifacts of vl.c being split up.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
It was merely a workaround and the real fix is done now.
This reverts commit ef845c3bf4.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Also for Linux AIO, don't call callbacks that don't belong to the active
AsyncContext.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Don't call callbacks that don't belong to the active AsyncContext.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
bdrv_read/write emulation is used as the perfect example why we need something
like AsyncContexts. So maybe they better start using it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Add the possibility to use AIO and BHs without allowing foreign callbacks to be
run. Basically, you put your own AIOs and BHs in a separate context. For
details see the comments in the source.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Instead of putting more and more stuff into vl.c, let's have the generic
functions that deal with asynchronous callbacks in their own file.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We'll leave some AIO completions unhandled when we can't call the callback.
qemu_aio_process_queue() is used later to run any callbacks that are left and
can be run then.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We need to process the request queue and run callbacks separately from reading
out the queue in a later patch, so split it out.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Note that errors are not being converted yet.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Note that errors are not being converted yet.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Note that errors are not being converted yet.
Signed-off-by: Luiz Capitulino <lcapitulino@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>
Error is 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>
Note that errors are not being converted yet.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Note that errors are not being converted yet.
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>
Mark McLoughlin