From 3b688d7a086d0438649ea37990c6e811954fc780 Mon Sep 17 00:00:00 2001 From: Sebastien Boeuf Date: Tue, 3 Jan 2023 11:51:07 +0100 Subject: vhost-vdpa: uAPI to resume the device This new ioctl adds support for resuming the device from userspace. This is required when trying to restore the device in a functioning state after it's been suspended. It is already possible to reset a suspended device, but that means the device must be reconfigured and all the IOMMU/IOTLB mappings must be recreated. This new operation allows the device to be resumed without going through a full reset. This is particularly useful when trying to perform offline migration of a virtual machine (also known as snapshot/restore) as it allows the VMM to resume the virtual machine back to a running state after the snapshot is performed. Acked-by: Jason Wang Signed-off-by: Sebastien Boeuf Message-Id: <73b75fb87d25cff59768b4955a81fe7ffe5b4770.1672742878.git.sebastien.boeuf@intel.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella --- include/uapi/linux/vhost.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h index f9f115a7c75b..92e1b700b51c 100644 --- a/include/uapi/linux/vhost.h +++ b/include/uapi/linux/vhost.h @@ -180,4 +180,12 @@ */ #define VHOST_VDPA_SUSPEND _IO(VHOST_VIRTIO, 0x7D) +/* Resume a device so it can resume processing virtqueue requests + * + * After the return of this ioctl the device will have restored all the + * necessary states and it is fully operational to continue processing the + * virtqueue descriptors. + */ +#define VHOST_VDPA_RESUME _IO(VHOST_VIRTIO, 0x7E) + #endif -- cgit v1.2.3