When vhost-user device cleanup, remove notifier MR and munmaps notifier
address in the event-handling thread, VM CPU thread writing the notifier
in concurrent fails with an error of accessing invalid address. It
happens because MR is still being referenced and accessed in another
thread while the underlying notifier mmap address is being freed and
becomes invalid.
This patch calls RCU and munmap notifiers in the callback after the
memory flatview update finish.
Fixes: 44866521bd ("vhost-user: support registering external host notifiers")
Cc: qemu-stable@nongnu.org
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Message-Id: <20220207071929.527149-3-xuemingl@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Notifier set when vhost-user backend asks qemu to mmap an FD and
offset. When vhost-user backend restart or getting killed, VQ notifier
FD and mmap addresses become invalid. After backend restart, MR contains
the invalid address will be restored and fail on notifier access.
On the other hand, qemu should munmap the notifier, release underlying
hardware resources to enable backend restart and allocate hardware
notifier resources correctly.
Qemu shouldn't reference and use resources of disconnected backend.
This patch removes VQ notifier restore, uses the default vhost-user
notifier to avoid invalid address access.
After backend restart, the backend should ask qemu to install a hardware
notifier if needed.
Fixes: 44866521bd ("vhost-user: support registering external host notifiers")
Cc: qemu-stable@nongnu.org
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Message-Id: <20220207071929.527149-2-xuemingl@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This change introduces a new feature to the vhost-user protocol allowing
a backend device to specify the maximum number of ram slots it supports.
At this point, the value returned by the backend will be capped at the
maximum number of ram slots which can be supported by vhost-user, which
is currently set to 8 because of underlying protocol limitations.
The returned value will be stored inside the VhostUserState struct so
that on device reconnect we can verify that the ram slot limitation
has not decreased since the last time the device connected.
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Message-Id: <1588533678-23450-4-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Take a VhostUserState* that can be pre-allocated, and initialize it
with the associated chardev.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
Message-Id: <20190308140454.32437-4-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch introduces VHOST_USER_PROTOCOL_F_HOST_NOTIFIER.
With this feature negotiated, vhost-user backend can register
memory region based host notifiers. And it will allow the guest
driver in the VM to notify the hardware accelerator at the
vhost-user backend directly.
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When multi queue is enabled e.g. for a virtio-net device,
each queue pair will have a vhost_dev, and the only thing
shared between vhost devs currently is the chardev. This
patch introduces a vhost-user state structure which will
be shared by all vhost devs of the same virtio device.
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
