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| author | Eugenio Pérez <eperezma@redhat.com> | 2022-08-10 20:15:11 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-08-11 11:31:15 +0300 |
| commit | f345a0143b4dd1cfc850009c6979a3801b86a06f (patch) | |
| tree | 7a3191db2733b0233903ac78eca7fd9ce44fc094 /drivers/vhost/vdpa.c | |
| parent | 0723f1df5c3ec8a1112d150dab98e149361ef488 (diff) | |
| download | linux-f345a0143b4dd1cfc850009c6979a3801b86a06f.tar.xz | |
vhost-vdpa: uAPI to suspend the device
The ioctl adds support for suspending the device from userspace.
This is a must before getting virtqueue indexes (base) for live migration,
since the device could modify them after userland gets them. There are
individual ways to perform that action for some devices
(VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no
way to perform it for any vhost device (and, in particular, vhost-vdpa).
After a successful return of the ioctl call the device must not process
more virtqueue descriptors. The device can answer to read or writes of
config fields as if it were not suspended. In particular, writing to
"queue_enable" with a value of 1 will not make the device start
processing buffers of the virtqueue.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20220810171512.2343333-4-eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost/vdpa.c')
| -rw-r--r-- | drivers/vhost/vdpa.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 092752fea8e1..166044642fd5 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -478,6 +478,22 @@ static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp) return 0; } +/* After a successful return of ioctl the device must not process more + * virtqueue descriptors. The device can answer to read or writes of config + * fields as if it were not suspended. In particular, writing to "queue_enable" + * with a value of 1 will not make the device start processing buffers. + */ +static long vhost_vdpa_suspend(struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + + if (!ops->suspend) + return -EOPNOTSUPP; + + return ops->suspend(vdpa); +} + static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, void __user *argp) { @@ -654,6 +670,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, case VHOST_VDPA_GET_VQS_COUNT: r = vhost_vdpa_get_vqs_count(v, argp); break; + case VHOST_VDPA_SUSPEND: + r = vhost_vdpa_suspend(v); + break; default: r = vhost_dev_ioctl(&v->vdev, cmd, argp); if (r == -ENOIOCTLCMD) |