This patch lets vhost support multiqueue. The idea is simple, just launching
multiple threads of vhost and let each of vhost thread processing a subset of
the virtqueues of the device. After this change each emulated device can have
multiple vhost threads as its backend.
To do this, a virtqueue index were introduced to record to first virtqueue that
will be handled by this vhost_net device. Based on this and nvqs, vhost could
calculate its relative index to setup vhost_net device.
Since we may have many vhost/net devices for a virtio-net device. The setting of
guest notifiers were moved out of the starting/stopping of a specific vhost
thread. The vhost_net_{start|stop}() were renamed to
vhost_net_{start|stop}_one(), and a new vhost_net_{start|stop}() were introduced
to configure the guest notifiers and start/stop all vhost/vhost_net devices.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Support backend guest notifier masking in vhost-net:
create eventfd at device init, when masked,
make vhost use that as eventfd instead of
sending an interrupt.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Move public headers to include/net, and leave private headers in net/.
Put the virtio headers in include/net/tap.h, removing the multiple copies
that existed. Leave include/net/tap.h as the interface for NICs, and
net/tap_int.h as the interface for OS-specific parts of the tap backend.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Modern linux supports arbitrary header size,
which makes it possible to pass mrg buf header
to tap directly without iovec mangling.
Use this capability when it is there.
This removes the need to deal with it in
vhost-net as we do now.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The path to /dev/vhost-net is currently hardcoded in vhost_dev_init().
This needs to be changed so that /dev/vhost-scsi can be used. Pass in
the device path instead of hardcoding it.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Now that VLANClientState has been renamed to NetClientState all 'vc'
local variables should be 'nc'. Much of the code already used 'nc' but
there are places where 'vc' needs to be renamed.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
The vlan feature is no longer part of net core. Rename VLANClientState
to NetClientState because net clients are not explicitly associated with
a vlan at all, instead they have a peer net client to which they are
connected.
This patch is a mechanical search-and-replace except for a few
whitespace fixups where changing VLANClientState to NetClientState
misaligned whitespace.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
All files under GPLv2 will get GPLv2+ changes starting tomorrow.
event_notifier.c and exec-obsolete.h were only ever touched by Red Hat
employees and can be relicensed now.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
When the vhost notifier is disabled, the userspace handler runs
immediately: virtio_pci_set_host_notifier_internal might
call virtio_queue_notify_vq.
Since the VQ state and the tap backend state aren't
recovered yet, this causes
"Guest moved used index from XXX to YYY" assertions.
The solution is to split out host notifier handling
from vhost VQ setup and disable notifiers as our last step
when we stop vhost-net. For symmetry enable them first thing
on start.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When qemu gets compiled without support of vhost-net, any attempt
to use it fails with a very clear error message:
qemu-system-x86_64: -netdev ...,vhost=on: vhost-net requested but could not be initialized
there's absolutely no reason given _why_ it coult not be
initialized, and even strace'ing the process in question
does not reveal any errors. So print a message telling
what's going on.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add support for event_idx feature, and utilize it to
reduce the number of interrupts and exits for the guest.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When MSI is off, each interrupt needs to be bounced through the io
thread when it's set/cleared, so vhost-net causes more context switches and
higher CPU utilization than userspace virtio which handles networking in
the same thread.
We'll need to fix this by adding level irq support in kvm irqfd,
for now disable vhost-net in these configurations.
Added a vhostforce flag to force vhost-net back on.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
file.index is unsigned, hence 'while (--file.index >= 0)'
will loop > forever. Change to while (file.index-- > 0).
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This header is not present on my system and causes a build
failure, but is also not used in these files, so remove it.
Signed-off-by: Mike McCormack <mikem@ring3k.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Fix build failure introduced by 0bfcd599e3
The format statement expects unsigned long on x86_64, but receives
unsigned long long, so gcc exits with an error.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
vhost in current kernels doesn't support mergeable buffers.
Disable this feature if vhost is enabled, until such
support is implemented.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This adds vhost net device support in qemu. Will be tied to tap device
and virtio by following patches. Raw backend is currently missing,
will be worked on/submitted separately.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
