diff options
| author | Sebastien Boeuf <sebastien.boeuf@intel.com> | 2023-01-03 11:51:07 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2023-02-21 01:26:56 +0100 |
| commit | 3b688d7a086d0438649ea37990c6e811954fc780 (patch) | |
| tree | bccd58f19543398649064ed4e3f9e3c30416f5f9 /drivers/vhost | |
| parent | vhost-vdpa: Introduce RESUME backend feature bit (diff) | |
| download | linux-3b688d7a086d0438649ea37990c6e811954fc780.tar.xz linux-3b688d7a086d0438649ea37990c6e811954fc780.zip | |
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 <jasowang@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Message-Id: <73b75fb87d25cff59768b4955a81fe7ffe5b4770.1672742878.git.sebastien.boeuf@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vdpa.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index abbe397b8509..23db92388393 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -506,6 +506,21 @@ static long vhost_vdpa_suspend(struct vhost_vdpa *v) return ops->suspend(vdpa); } +/* After a successful return of this ioctl the device resumes processing + * virtqueue descriptors. The device becomes fully operational the same way it + * was before it was suspended. + */ +static long vhost_vdpa_resume(struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + + if (!ops->resume) + return -EOPNOTSUPP; + + return ops->resume(vdpa); +} + static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, void __user *argp) { @@ -691,6 +706,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, case VHOST_VDPA_SUSPEND: r = vhost_vdpa_suspend(v); break; + case VHOST_VDPA_RESUME: + r = vhost_vdpa_resume(v); + break; default: r = vhost_dev_ioctl(&v->vdev, cmd, argp); if (r == -ENOIOCTLCMD) |