IFCVF HW supports operation with vq size less than the max size,
as the spec required.
This commit implements vdpa_config_ops.get_vq_num_min to report
the minimal size of the virtqueues, which gives vDPA framework
a chance to reduce the vring size.
We need at least one descriptor to be functional, but it is better
no less than 64 to meet ceratin performance requirements.
Actually the framework would allocate at least a PAGE for the vq.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240202163905.8834-11-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Since we already implemented vdpa_config_ops.get_vq_size,
so get_max_vq_size can return the acutal max size of the
virtqueues other than the max allowed safe size.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240202163905.8834-10-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit implements vdpa_ops.get_vq_size to report
the size of a specific virtqueue.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240202163905.8834-4-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit implements a better layout of the
live migration bar, therefore the accessors for virtqueue
state have been refactored.
This commit also add a comment to the probing-ids list,
indicating this driver drives F2000X-PL virtio-net
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20230612151420.1019504-4-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Rather than a hardcode, this commit detects
and reports the max value of allowed size
of the virtqueues
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20230612151420.1019504-3-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit dynamically allocates the data
stores for the virtqueues based on
virtio_pci_common_cfg.num_queues.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20230612151420.1019504-2-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
VIRTIO_CONFIG_S_FAILED indicates the guest driver has given up
the device due to fatal errors. So it is the guest decision,
the vendor driver should not set this status to the device.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230526145254.39537-6-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit synchronize irqs of the virtqueues
and config space in the reset routine.
Thus ifcvf_stop() and reset() are refactored as well.
This commit renames ifcvf_stop_hw() to ifcvf_stop()
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230526145254.39537-5-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Rather than former lazy-initialization mechanism,
now the virtqueue operations and driver_features related
ops access the virtio registers directly to take
immediate actions. So ifcvf_start_datapath() should
retire.
ifcvf_add_status() is retierd because we should not change
device status by a vendor driver's decision, this driver should
only set device status which is from virito drivers
upon vdpa_ops.set_status()
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230526145254.39537-4-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit implements a new function ifcvf_get_driver_feature()
which read driver_features from virtio registers.
To be less ambiguous, ifcvf_set_features() is renamed to
ifcvf_set_driver_features(), and ifcvf_get_features()
is renamed to ifcvf_get_dev_features() which returns
the provisioned vDPA device features.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230526145254.39537-3-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
In this commit, virtqueue operations including:
set_vq_num(), set_vq_address(), set_vq_ready()
and get_vq_ready() access PCI registers directly
to take immediate actions.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230526145254.39537-2-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit implements features provisioning for ifcvf, that means:
1)checkk whether the provisioned features are supported by
the management device
2)vDPA device only presents selected feature bits
Examples:
a)The management device supported features:
$ vdpa mgmtdev show pci/0000:01:00.5
pci/0000:01:00.5:
supported_classes net
max_supported_vqs 9
dev_features MTU MAC MRG_RXBUF CTRL_VQ MQ ANY_LAYOUT VERSION_1 ACCESS_PLATFORM
b)Provision a vDPA device with all supported features:
$ vdpa dev add name vdpa0 mgmtdev pci/0000:01:00.5
$ vdpa/vdpa dev config show vdpa0
vdpa0: mac 00:e8:ca:11:be:05 link up link_announce false max_vq_pairs 4 mtu 1500
negotiated_features MRG_RXBUF CTRL_VQ MQ VERSION_1 ACCESS_PLATFORM
c)Provision a vDPA device with a subset of the supported features:
$ vdpa dev add name vdpa0 mgmtdev pci/0000:01:00.5 device_features 0x300020020
$ vdpa dev config show vdpa0
mac 00:e8:ca:11:be:05 link up link_announce false
negotiated_features CTRL_VQ VERSION_1 ACCESS_PLATFORM
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20221125145724.1129962-13-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit retires ifcvf_private_to_vf, because
the vf is already a member of the adapter,
so it could be easily addressed by adapter->vf.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20221125145724.1129962-12-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The adapter is the container of the vdpa_device,
this commits allocate the adapter in dev_add()
rather than in probe(). So that the vdpa_device()
could be re-created when the userspace creates
the vdpa device, and free-ed in dev_del()
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-11-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit allocates the hw structure in the
management device structure. So the hardware
can be initialized once the management device
is allocated in probe.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-10-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
All ifcvf_request_irq's callees are refactored
to work on ifcvf_hw, so it should be decoupled
from the adapter as well
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-9-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit decouples the config irq requester, the device
shared irq requester and the MSI vectors allocator from
the adapter. So they can be safely invoked since probe
before the adapter is allocated.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-8-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit decouples the vq irq requester from the adapter,
so that these functions can be invoked since probe.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-7-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit decouples config IRQ releaser from the adapter,
so that it could be invoked once probe or in err handlers.
ifcvf_free_irq() works on ifcvf_hw in this commit
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-6-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit decouples the IRQ releasers from the
adapter, so that these functions could be
safely invoked once probe
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-5-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit reverses the order of allocating the
management device and the adapter. So that it would
be possible to move the allocation of the adapter
to dev_add().
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-4-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit decopules the config space ops from the
adapter layer, so these functions can be invoked
once the device is probed.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-3-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit gets rid of ifcvf_adapter in hw features related
functions in ifcvf_base. Then these functions are more rubust
and de-coupling from the ifcvf_adapter layer. So these
functions could be invoded once the device is probed, even
before the adapter is allocaed.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-2-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
ifcvf_mgmt_dev leaks memory if it is not freed before
returning. Call is made to correct return statement
so memory does not leak. ifcvf_init_hw does not take
care of this so it is needed to do it here.
Signed-off-by: Tanmay Bhushan <007047221b@gmail.com>
Message-Id: <772e9fe133f21fa78fb98a2ebe8969efbbd58e3c.camel@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Zhu Lingshan <lingshan.zhu@intel.com>
The q_pair_id to address a queue pair in the lm bar should be
calculated by queue_id / 2 rather than queue_id / nr_vring.
Fixes: 2ddae773c9 ("vDPA/ifcvf: detect and use the onboard number of queues directly")
Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20220923091013.191-1-angus.chen@jaguarmicro.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Adapting to current netlink interfaces, this commit allows userspace
to query feature bits and MQ capability of a management device.
Currently both the vDPA device and the management device are the VF itself,
thus this ifcvf should initialize the virtio capabilities in probe() before
setting up the struct vdpa_mgmt_dev.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20220722115309.82746-3-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Drivers must not access a BAR outside the capability length,
and for a virtio device, ifcvf driver should not report any non-standard
capability contents to the upper layers.
Function ifcvf_get_config_size() is introduced here to return a safe value
of the device config capability size.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20220722115309.82746-2-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The assignment to pointer cfg is duplicated, the second assignment
is redundant and can be removed.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Message-Id: <20220704190456.593464-1-colin.i.king@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
There is a typo(does't) in comments.
It maybe 'doesn't' instead of 'does't'.
Signed-off-by: Zhang Jiaming <jiaming@nfschina.com>
Message-Id: <20220704024104.15535-1-jiaming@nfschina.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
We should set the pci driver data in probe instead of the vdpa device
adding callback. Otherwise if no vDPA device is created we will lose
the pointer to the management device.
Fixes: 6b5df347c6 ("vDPA/ifcvf: implement management netlink framework for ifcvf")
Tested-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220524055557.1938-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Static checkers are not informed that config_vector is controlled
by vf->msix_vector_status, which can only be
MSIX_VECTOR_SHARED_VQ_AND_CONFIG, MSIX_VECTOR_SHARED_VQ_AND_CONFIG
and MSIX_VECTOR_DEV_SHARED.
This commit uses an "if...elseif...else" code block to tell the
checkers that it is a complete set, and config_vector can be
initialized anyway
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20220424072806.1083189-1-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
This patches introduces the multiple address spaces support for vDPA
device. This idea is to identify a specific address space via an
dedicated identifier - ASID.
During vDPA device allocation, vDPA device driver needs to report the
number of address spaces supported by the device then the DMA mapping
ops of the vDPA device needs to be extended to support ASID.
This helps to isolate the environments for the virtqueue that will not
be assigned directly. E.g in the case of virtio-net, the control
virtqueue will not be assigned directly to guest.
As a start, simply claim 1 virtqueue groups and 1 address spaces for
all vDPA devices. And vhost-vDPA will simply reject the device with
more than 1 virtqueue groups or address spaces.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
Message-Id: <20220330180436.24644-7-gdawar@xilinx.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch introduces virtqueue groups to vDPA device. The virtqueue
group is the minimal set of virtqueues that must share an address
space. And the address space identifier could only be attached to
a specific virtqueue group.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
Message-Id: <20220330180436.24644-6-gdawar@xilinx.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
On some platforms/devices, there may not be enough MSI vectors
allocated for the virtqueues and config changes. In such a case,
the interrupt sources(virtqueues, config changes) must share
an IRQ/vector, to avoid initialization failures, keep
the device functional.
This commit handles three cases:
(1) number of the allocated vectors == the number of virtqueues + 1
(config changes), every virtqueue and the config interrupt has
a separated vector/IRQ, the best and the most likely case.
(2) number of the allocated vectors is less than the best case, but
greater than 1. In this case, all virtqueues share a vector/IRQ,
the config interrupt has a separated vector/IRQ
(3) only one vector is allocated, in this case, the virtqueues and
the config interrupt share a vector/IRQ. The worst and most
unlikely case.
Otherwise, it needs to fail.
This commit introduces some helper functions:
ifcvf_set_vq_vector() and ifcvf_set_config_vector() sets virtqueue
vector and config vector in the device config space, so that
the device can send interrupt DMA.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20220222115428.998334-5-lingshan.zhu@intel.com
Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20220315124130.1710030-1-trix@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Provide an interface to read the negotiated features. This is needed
when building the netlink message in vdpa_dev_net_config_fill().
Also fix the implementation of vdpa_dev_net_config_fill() to use the
negotiated features instead of the device features.
To make APIs clearer, make the following name changes to struct
vdpa_config_ops so they better describe their operations:
get_features -> get_device_features
set_features -> set_driver_features
Finally, add get_driver_features to return the negotiated features and
add implementation to all the upstream drivers.
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-2-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit fixes a misuse of virtio-net device config size issue
for virtio-block devices.
A new member config_size in struct ifcvf_hw is introduced and would
be initialized through vdpa_dev_add() to record correct device
config size.
To be more generic, rename ifcvf_hw.net_config to ifcvf_hw.dev_config,
the helpers ifcvf_read/write_net_config() to ifcvf_read/write_dev_config()
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Reported-and-suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Fixes: 6ad31d162a ("vDPA/ifcvf: enable Intel C5000X-PL virtio-block for vDPA")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211201081255.60187-1-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
$ vdpa dev add name bar mgmtdev vdpasim_net mac 00:11:22:33:44:55 mtu 9000
$ vdpa dev config show
bar: mac 00:11:22:33:44:55 link up link_announce false mtu 9000
$ vdpa dev config show -jp
{
"config": {
"bar": {
"mac": "00:11:22:33:44:55",
"link ": "up",
"link_announce ": false,
"mtu": 9000,
}
}
}
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211026175519.87795-5-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
This patch introduces an attribute for vDPA device to indicate
whether virtual address can be used. If vDPA device driver set
it, vhost-vdpa bus driver will not pin user page and transfer
userspace virtual address instead of physical address during
DMA mapping. And corresponding vma->vm_file and offset will be
also passed as an opaque pointer.
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210831103634.33-11-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This adds a new callback to support device specific reset
behavior. The vdpa bus driver will call the reset function
instead of setting status to zero during resetting.
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210831103634.33-6-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit enbales multi-queue and control vq
features for ifcvf
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20210818095714.3220-3-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
To enable this multi-queue feature for ifcvf, this commit
intends to detect and use the onboard number of queues
directly than IFCVF_MAX_QUEUE_PAIRS = 1 (removed)
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20210818095714.3220-2-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
This commit implements the management netlink framework for ifcvf,
including register and add / remove a device
It works with iproute2:
[root@localhost lszhu]# vdpa mgmtdev show -jp
{
"mgmtdev": {
"pci/0000:01:00.5": {
"supported_classes": [ "net" ]
},
"pci/0000:01:00.6": {
"supported_classes": [ "net" ]
}
}
}
[root@localhost lszhu]# vdpa dev add mgmtdev pci/0000:01:00.5 name vdpa0
[root@localhost lszhu]# vdpa dev add mgmtdev pci/0000:01:00.6 name vdpa1
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210812032454.24486-3-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit introduces a new function get_dev_type() which returns
the virtio device id of a device, to avoid duplicated code.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210812032454.24486-2-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The vdpa_alloc_device() returns an error pointer upon
failure, not NULL. To handle the failure correctly, this
replaces NULL check with IS_ERR() check and propagate the
error upwards.
Fixes: 5a2414bc45 ("virtio: Intel IFC VF driver for VDPA")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210715080026.242-3-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
This patch extends the vdpa_vq_state to support packed virtqueue
state which is basically the device/driver ring wrap counters and the
avail and used index. This will be used for the virito-vdpa support
for the packed virtqueue and the future vhost/vhost-vdpa support for
the packed virtqueue.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210602021536.39525-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
This commit implements doorbell mapping feature for ifcvf.
This feature maps the notify page to userspace, to eliminate
vmexit when kick a vq.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20210602084550.289599-3-lingshan.zhu@intel.com
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
