| Message ID | 20220810171512.2343333-4-eperezma@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Implement vdpasim suspend operation | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Wed, Aug 10, 2022 at 07:15:11PM +0200, Eugenio Pérez wrote: > 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: <20220623160738.632852-4-eperezma@redhat.com> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> You are not supposed to include upstream maintainer's signoff like this. > --- > v7: Delete argument to ioctl, unused > --- > drivers/vhost/vdpa.c | 19 +++++++++++++++++++ > include/uapi/linux/vhost.h | 9 +++++++++ > 2 files changed, 28 insertions(+) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 3d636e192061..7fa671ac4bdf 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) > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h > index cab645d4a645..f9f115a7c75b 100644 > --- a/include/uapi/linux/vhost.h > +++ b/include/uapi/linux/vhost.h > @@ -171,4 +171,13 @@ > #define VHOST_VDPA_SET_GROUP_ASID _IOW(VHOST_VIRTIO, 0x7C, \ > struct vhost_vring_state) > > +/* Suspend a device so it does not process virtqueue requests anymore > + * > + * After the return of ioctl the device must preserve all the necessary state > + * (the virtqueue vring base plus the possible device specific states) that is > + * required for restoring in the future. The device must not change its > + * configuration after that point. > + */ > +#define VHOST_VDPA_SUSPEND _IO(VHOST_VIRTIO, 0x7D) > + > #endif > -- > 2.31.1
On Thu, Aug 11, 2022 at 10:29 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Wed, Aug 10, 2022 at 07:15:11PM +0200, Eugenio Pérez wrote: > > 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: <20220623160738.632852-4-eperezma@redhat.com> > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > You are not supposed to include upstream maintainer's signoff > like this. > I'm very sorry, I modified the commits in your vhost branch and I left the signoff (and message-id) lines by mistake. > > --- > > v7: Delete argument to ioctl, unused > > --- > > drivers/vhost/vdpa.c | 19 +++++++++++++++++++ > > include/uapi/linux/vhost.h | 9 +++++++++ > > 2 files changed, 28 insertions(+) > > > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > > index 3d636e192061..7fa671ac4bdf 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) > > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h > > index cab645d4a645..f9f115a7c75b 100644 > > --- a/include/uapi/linux/vhost.h > > +++ b/include/uapi/linux/vhost.h > > @@ -171,4 +171,13 @@ > > #define VHOST_VDPA_SET_GROUP_ASID _IOW(VHOST_VIRTIO, 0x7C, \ > > struct vhost_vring_state) > > > > +/* Suspend a device so it does not process virtqueue requests anymore > > + * > > + * After the return of ioctl the device must preserve all the necessary state > > + * (the virtqueue vring base plus the possible device specific states) that is > > + * required for restoring in the future. The device must not change its > > + * configuration after that point. > > + */ > > +#define VHOST_VDPA_SUSPEND _IO(VHOST_VIRTIO, 0x7D) > > + > > #endif > > -- > > 2.31.1 >
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 3d636e192061..7fa671ac4bdf 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) diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h index cab645d4a645..f9f115a7c75b 100644 --- a/include/uapi/linux/vhost.h +++ b/include/uapi/linux/vhost.h @@ -171,4 +171,13 @@ #define VHOST_VDPA_SET_GROUP_ASID _IOW(VHOST_VIRTIO, 0x7C, \ struct vhost_vring_state) +/* Suspend a device so it does not process virtqueue requests anymore + * + * After the return of ioctl the device must preserve all the necessary state + * (the virtqueue vring base plus the possible device specific states) that is + * required for restoring in the future. The device must not change its + * configuration after that point. + */ +#define VHOST_VDPA_SUSPEND _IO(VHOST_VIRTIO, 0x7D) + #endif