Commit Graph

29 Commits

Author SHA1 Message Date
Laurent Vivier
ba5acc5d6e net: Add is_vhost_user flag to vhost_net struct
Introduce a boolean is_vhost_user field to the vhost_net
structure. This flag is initialized during vhost_net_init based
on whether the backend is vhost-user.

This refactoring simplifies checks for vhost-user specific behavior,
replacing direct comparisons of 'net->nc->info->type' with the new
flag. It improves readability and encapsulates the backend type
information directly within the vhost_net instance.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2025-07-14 13:27:09 +08:00
Laurent Vivier
33b78a30a3 net: Allow network backends to advertise max TX queue size
This commit refactors how the maximum transmit queue size for
virtio-net devices is determined, making the mechanism more generic
and extensible.

Previously, virtio_net_max_tx_queue_size() contained hardcoded
checks for specific network backend types (vhost-user and
vhost-vdpa) to determine their supported maximum queue size. This
created direct dependencies and would require modifications for
every new backend that supports variable queue sizes.

To improve flexibility, a new max_tx_queue_size field is added
to the vhost_net structure. This allows each network backend
to advertise its supported maximum transmit queue size directly.

The virtio_net_max_tx_queue_size() function now retrieves the max
TX queue size from the vhost_net struct, if available and set.
Otherwise, it defaults to VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2025-07-14 13:27:09 +08:00
Laurent Vivier
1652f1b335 net: Add save_acked_features callback to vhost_net
This commit introduces a save_acked_features function pointer to
vhost_net and converts the vhost_net function into a generic dispatcher.

The vhost-user backend provides the callback, making its function static.
With this change, no other module has a direct dependency on the
vhost-user implementation.

This cleanup allows for the complete removal of the net/vhost-user.h
header file.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2025-07-14 13:27:09 +08:00
Laurent Vivier
bd38794a11 net: Add get_acked_features callback to VhostNetOptions
This patch continues the effort to decouple the generic vhost layer
from specific network backend implementations.

Previously, the vhost_net initialization code contained a hardcoded
check for the vhost-user client type to retrieve its acked features
by calling vhost_user_get_acked_features(). This exposed an
internal vhost-user function in a public header and coupled the two
modules.

The vhost-user backend is updated to provide a callback, and its
getter function is now static. The call site in vhost_net.c is
simplified to use the new generic helper, removing the type check and
the direct dependency.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2025-07-14 13:27:09 +08:00
Laurent Vivier
effdacbf28 net: Consolidate vhost feature bits into vhost_net structure
Previously, the vhost_net_get_feature_bits() function in
hw/net/vhost_net.c used a large switch statement to determine
the appropriate feature bits based on the NetClientDriver type.

This created unnecessary coupling between the generic vhost layer
and specific network backends (like TAP, vhost-user, and
vhost-vdpa).

This patch moves the definition of vhost feature bits directly into the
vhost_net structure for each relevant network client.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2025-07-14 13:27:09 +08:00
Laurent Vivier
7136352b40 vhost_net: Rename vhost_set_vring_enable() for clarity
This is a cosmetic change with no functional impact.

The function vhost_set_vring_enable() is specific to vhost_net and
is used outside of vhost_net.c (specifically, in
hw/net/virtio-net.c). To prevent confusion with other similarly named
vhost functions, such as the one found in cryptodev-vhost.c, it has
been renamed to vhost_net_set_vring_enable(). This clarifies that the
function belongs to the vhost_net module.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2025-07-14 13:27:09 +08:00
Akihiko Odaki
d9b33018a0 Revert "tap: setting error appropriately when calling net_init_tap_one()"
This reverts commit 46d4d36d0b.

The reverted commit changed to emit warnings instead of errors when
vhost is requested but vhost initialization fails if vhostforce option
is not set.

However, vhostforce is not meant to ignore vhost errors. It was once
introduced as an option to commit 5430a28fe4 ("vhost: force vhost off
for non-MSI guests") to force enabling vhost for non-MSI guests, which
will have worse performance with vhost. The option was deprecated with
commit 1e7398a140 ("vhost: enable vhost without without MSI-X") and
changed to behave identical with the vhost option for compatibility.

Worse, commit bf769f742c ("virtio: del net client if net_init_tap_one
failed") changed to delete the client when vhost fails even when the
failure only results in a warning. The leads to an assertion failure
for the -netdev command line option.

The reverted commit was intended to avoid that the vhost initialization
failure won't result in a corrupted netdev. This problem should have
been fixed by deleting netdev when the initialization fails instead of
ignoring the failure with an arbitrary option. Fortunately, commit
bf769f742c ("virtio: del net client if net_init_tap_one failed"),
mentioned earlier, implements this behavior.

Restore the correct semantics and fix the assertion failure for the
-netdev command line option by reverting the problematic commit.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-03-29 14:59:07 +08:00
Cindy Lu
8aab0d1dbe virtio-net: add support for configure interrupt
Add functions to support configure interrupt in virtio_net
Add the functions to support vhost_net_config_pending
and vhost_net_config_mask.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20221222070451.936503-9-lulu@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-01-08 01:54:22 -05:00
Hyman Huang(黄勇)
c9bdc449f9 vhost-user: Fix the virtio features negotiation flaw
This patch aims to fix unexpected negotiation features for
vhost-user netdev interface.

When openvswitch reconnect Qemu after an unexpected disconnection
and Qemu therefore start the vhost_dev, acked_features field in
vhost_dev is initialized with value fetched from acked_features
field in NetVhostUserState, which should be up-to-date at that
moment but Qemu could not make it actually during the time window
of virtio features negotiation.

So we save the acked_features right after being configured by
guest virtio driver so it can be used to restore acked_features
field in vhost_dev correctly.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Signed-off-by: Guoyi Tu <tugy@chinatelecom.cn>
Signed-off-by: Liuxiangdong <liuxiangdong5@huawei.com>
Message-Id: <b9f8cf5561a79ea65ea38960e5a5e6d3707eef0a.1671627406.git.huangy81@chinatelecom.cn>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-01-08 01:54:22 -05:00
Kangjie Xu
10f8a115a8 vhost-net: vhost-kernel: introduce vhost_net_virtqueue_restart()
Introduce vhost_net_virtqueue_restart(), which can restart the
specific virtqueue when the vhost net started running before.
If it fails to restart the virtqueue, the device will be stopped.

Here we do not reuse vhost_net_start_one() or vhost_dev_start()
because they work at queue pair level. The mem table and features
do not change, so we can call the vhost_virtqueue_start() to
restart a specific queue.

This patch only considers the case of vhost-kernel, when
NetClientDriver is NET_CLIENT_DRIVER_TAP.

Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-11-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-07 13:12:20 -05:00
Kangjie Xu
c2daa08e17 vhost-net: vhost-kernel: introduce vhost_net_virtqueue_reset()
Introduce vhost_virtqueue_reset(), which can reset the specific
virtqueue in the device. Then it will unmap vrings and the desc
of the virtqueue.

Here we do not reuse the vhost_net_stop_one() or vhost_dev_stop(),
because they work at queue pair level. We do not use
vhost_virtqueue_stop() because it may stop the device in the
backend.

This patch only considers the case of vhost-kernel, when
NetClientDriver is NET_CLIENT_DRIVER_TAP.

Furthermore, we do not need net->nc->info->poll() because
it enables userspace datapath and we want to stop all
datapaths for this reset virtqueue here.

Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-10-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-07 13:12:20 -05:00
Michael S. Tsirkin
b3ef6664b7 Revert "virtio-net: add support for configure interrupt"
This reverts commit 497679d510.

Fixes: 497679d510 ("virtio-net: add support for configure interrupt")
Cc: "Cindy Lu" <lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-10 16:00:54 -05:00
Cindy Lu
497679d510 virtio-net: add support for configure interrupt
Add functions to support configure interrupt in virtio_net
The functions are config_pending and config_mask, while
this input idx is VIRTIO_CONFIG_IRQ_IDX will check the
function of configure interrupt.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-9-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-07 05:19:55 -05:00
Jason Wang
05ba3f63d1 vhost-net: control virtqueue support
We assume there's no cvq in the past, this is not true when we need
control virtqueue support for vhost-user backends. So this patch
implements the control virtqueue support for vhost-net. As datapath,
the control virtqueue is also required to be coupled with the
NetClientState. The vhost_net_start/stop() are tweaked to accept the
number of datapath queue pairs plus the the number of control
virtqueue for us to start and stop the vhost device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211020045600.16082-7-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-10-20 04:44:05 -04:00
Jason Wang
6a756d1495 vhost_net: do not assume nvqs is always 2
This patch switches to initialize dev.nvqs from the VhostNetOptions
instead of assuming it was 2. This is useful for implementing control
virtqueue support which will be a single vhost_net structure with a
single cvq.

Note that nvqs is still set to 2 for all users and this patch does not
change functionality.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20210903091031.47303-6-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 17:34:05 -04:00
Cindy Lu
38140cc4d9 vhost_net: introduce set_config & get_config
This patch introduces set_config & get_config  method which allows
vhost_net set/get the config to backend

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20200701145538.22333-13-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2020-07-03 07:57:04 -04:00
Jay Zhou
46d4d36d0b tap: setting error appropriately when calling net_init_tap_one()
If netdev_add tap,id=net0,...,vhost=on failed in net_init_tap_one(),
the followed up device_add virtio-net-pci,netdev=net0 will fail
too, prints:

   TUNSETOFFLOAD ioctl() failed: Bad file descriptor TUNSETOFFLOAD
   ioctl() failed: Bad file descriptor

The reason is that the fd of tap is closed when error occured after
calling net_init_tap_one().

The fd should be closed when calling net_init_tap_one failed:
   - if tap_set_sndbuf() failed
   - if tap_set_sndbuf() succeeded but vhost failed to open or
     initialize with vhostforce flag on
   - with wrong vhost command line parameter
The fd should not be closed just because vhost failed to open or
initialize but without vhostforce flag. So the followed up
device_add can fall back to userspace virtio successfully.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Suggested-by: Igor Mammedov <imammedo@redhat.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-03-05 10:30:16 +08:00
Maxime Coquelin
45a368ad4f vhost-net: Notify the backend about the host MTU
This patch provides a way for virtio-net to notify the
backend about the host MTU set by the user.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Aaron Conole <aconole@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-01-10 07:02:53 +02:00
Jason Wang
69e87b3268 tap: vhost busy polling support
This patch add the capability of basic vhost net busy polling which is
supported by recent kernel. User could configure the maximum number of
us that could be spent on busy polling through a new property of tap
"poll-us".

Cc: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-07-07 14:29:04 +08:00
Marc-André Lureau
a463215b08 vhost-net: save & restore vhost-user acked features
The initial vhost-user connection sets the features to be negotiated
with the driver. Renegotiation isn't possible without device reset.

To handle reconnection of vhost-user backend, ensure the same set of
features are provided, and reuse already acked features.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-06-17 03:28:03 +03:00
Thibaut Collet
3e866365e1 vhost user: add rarp sending after live migration for legacy guest
A new vhost user message is added to allow QEMU to ask to vhost user backend to
broadcast a fake RARP after live migration for guest without GUEST_ANNOUNCE
capability.

This new message is sent only if the backend supports the new
VHOST_USER_PROTOCOL_F_RARP protocol feature.
The payload of this new message is the MAC address of the guest (not known by
the backend). The MAC address is copied in the first 6 bytes of a u64 to avoid
to create a new payload message type.

This new message has no equivalent ioctl so a new callback is added in the
userOps structure to send the request.

Upon reception of this new message the vhost user backend must generate and
broadcast a fake RARP request to notify the migration is terminated.

Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
[Rebased and fixed checkpatch errors - Marc-André]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Changchun Ouyang
7263a0ad78 vhost-user: add a new message to disable/enable a specific virt queue.
Add a new message, VHOST_USER_SET_VRING_ENABLE, to enable or disable
a specific virt queue, which is similar to attach/detach queue for
tap device.

virtio driver on guest doesn't have to use max virt queue pair, it
could enable any number of virt queue ranging from 1 to max virt
queue pair.

Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:53 +03:00
Yuanhan Liu
e2051e9e00 vhost-user: add VHOST_USER_GET_QUEUE_NUM message
This is for querying how many queues the backend supports if it has mq
support(when VHOST_USER_PROTOCOL_F_MQ flag is set from the quried
protocol features).

vhost_net_get_max_queues() is the interface to export that value, and
to tell if the backend supports # of queues user requested, which is
done in the following patch.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:52 +03:00
Pankaj Gupta
1e7398a140 vhost: enable vhost without without MSI-X
We use vhostforce to enable vhost even if Guests don't have MSI-X
support and we fall back to QEMU virtio-net.

This gives a very small performance gain, but the disadvantage
is that guest now controls which virtio code is running
(qemu or vhost) so our attack surface is doubled.

This patch will enable vhost unconditionally whenever it's requested.
For compatibility, enable vhost when vhostforce is set, as well.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
2015-06-19 12:17:49 +02:00
Cornelia Huck
9a2ba82302 vhost: 64 bit features
Make sure that all vhost interfaces use 64 bit features, as the virtio
core does, and make sure to use ULL everywhere possible to be on the
safe side.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10 18:15:04 +02:00
Nikolay Nikolaev
1a1bfac9ee Add vhost-backend and VhostBackendType
Use vhost_set_backend_type to initialise a proper vhost_ops structure.
In vhost_net_init and vhost_net_start_one call conditionally TAP related
initialisation depending on the vhost backend type.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-19 16:41:56 +03:00
Nikolay Nikolaev
81647a655f vhost_net_init will use VhostNetOptions to get all its arguments
vhost_dev_init will replace devfd and devpath with a single opaque argument.
This is initialised with a file descriptor. When TAP is used (through
vhost_net), open /dev/vhost-net and pass the fd as an opaque parameter in
VhostNetOptions. The same applies to vhost-scsi - open /dev/vhost-scsi and
pass the fd.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-19 16:41:56 +03:00
Nikolay Nikolaev
ed8b4afe5f Refactor virtio-net to use generic get_vhost_net
This decouples virtio-net from the TAP netdev backend and allows support
for other backends to be implemented.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-19 16:41:55 +03:00
Paolo Bonzini
0d09e41a51 hw: move headers to include/
Many of these should be cleaned up with proper qdev-/QOM-ification.
Right now there are many catch-all headers in include/hw/ARCH depending
on cpu.h, and this makes it necessary to compile these files per-target.
However, fixing this does not belong in these patches.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-04-08 18:13:10 +02:00