Jason Wang
2022-Oct-17 07:20 UTC
[PATCH v2 2/4] vhost-vdpa: Introduce RESUME backend feature bit
On Fri, Oct 14, 2022 at 7:15 PM <sebastien.boeuf at intel.com> wrote:> > From: Sebastien Boeuf <sebastien.boeuf at intel.com> > > Userspace knows if the device can be resumed or not by checking this > feature bit. > > It's only exposed if the vdpa driver backend implements the resume() > operation callback. Userspace trying to negotiate this feature when it > hasn't been exposed will result in an error. > > Signed-off-by: Sebastien Boeuf <sebastien.boeuf at intel.com>Acked-by: Jason Wang <jasowang at redhat.com>> --- > drivers/vhost/vdpa.c | 16 +++++++++++++++- > include/uapi/linux/vhost_types.h | 2 ++ > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 166044642fd5..833617d00ef6 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -355,6 +355,14 @@ static bool vhost_vdpa_can_suspend(const struct vhost_vdpa *v) > return ops->suspend; > } > > +static bool vhost_vdpa_can_resume(const struct vhost_vdpa *v) > +{ > + struct vdpa_device *vdpa = v->vdpa; > + const struct vdpa_config_ops *ops = vdpa->config; > + > + return ops->resume; > +} > + > static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) > { > struct vdpa_device *vdpa = v->vdpa; > @@ -602,11 +610,15 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, > if (copy_from_user(&features, featurep, sizeof(features))) > return -EFAULT; > if (features & ~(VHOST_VDPA_BACKEND_FEATURES | > - BIT_ULL(VHOST_BACKEND_F_SUSPEND))) > + BIT_ULL(VHOST_BACKEND_F_SUSPEND) | > + BIT_ULL(VHOST_BACKEND_F_RESUME))) > return -EOPNOTSUPP; > if ((features & BIT_ULL(VHOST_BACKEND_F_SUSPEND)) && > !vhost_vdpa_can_suspend(v)) > return -EOPNOTSUPP; > + if ((features & BIT_ULL(VHOST_BACKEND_F_RESUME)) && > + !vhost_vdpa_can_resume(v)) > + return -EOPNOTSUPP; > vhost_set_backend_features(&v->vdev, features); > return 0; > } > @@ -658,6 +670,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, > features = VHOST_VDPA_BACKEND_FEATURES; > if (vhost_vdpa_can_suspend(v)) > features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND); > + if (vhost_vdpa_can_resume(v)) > + features |= BIT_ULL(VHOST_BACKEND_F_RESUME); > if (copy_to_user(featurep, &features, sizeof(features))) > r = -EFAULT; > break; > diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h > index 53601ce2c20a..c5690a8992d8 100644 > --- a/include/uapi/linux/vhost_types.h > +++ b/include/uapi/linux/vhost_types.h > @@ -163,5 +163,7 @@ struct vhost_vdpa_iova_range { > #define VHOST_BACKEND_F_IOTLB_ASID 0x3 > /* Device can be suspended */ > #define VHOST_BACKEND_F_SUSPEND 0x4 > +/* Device can be resumed */ > +#define VHOST_BACKEND_F_RESUME 0x5 > > #endif > -- > 2.34.1 > > --------------------------------------------------------------------- > Intel Corporation SAS (French simplified joint stock company) > Registered headquarters: "Les Montalets"- 2, rue de Paris, > 92196 Meudon Cedex, France > Registration Number: 302 456 199 R.C.S. NANTERRE > Capital: 5 208 026.16 Euros > > This e-mail and any attachments may contain confidential material for > the sole use of the intended recipient(s). Any review or distribution > by others is strictly prohibited. If you are not the intended > recipient, please contact the sender and delete all copies. >