On Mon, May 11, 2026 at 11:46 AM Dragos Tatulea <[email protected]> wrote: > > The commit in the fixes tag blocked VHOST_VDPA_SET_GROUP_ASID operations > once DRIVER_OK is set. That is too strict for devices which can safely > handle this during live migration flows. > > Bring back this behavior under a new vhost backend feature flag. The > feature is supported by mlx5 and vdpa_sim devices. > > Fixes: 3543b04a4ea3 ("vhost: forbid change vq groups ASID if DRIVER_OK is > set") > Signed-off-by: Dragos Tatulea <[email protected]> > Reviewed-by: Shahar Shitrit <[email protected]>
Acked-by: Eugenio Pérez <[email protected]> > --- > drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 ++- > drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 ++- > drivers/vhost/vdpa.c | 13 +++++++++++-- > include/uapi/linux/vhost_types.h | 4 ++++ > 4 files changed, 19 insertions(+), 4 deletions(-) > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c > b/drivers/vdpa/mlx5/net/mlx5_vnet.c > index ad0d5fbbbca8..f89177957c76 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > @@ -2906,7 +2906,8 @@ static void unregister_link_notifier(struct > mlx5_vdpa_net *ndev) > > static u64 mlx5_vdpa_get_backend_features(const struct vdpa_device *vdpa) > { > - return BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK); > + return BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK) | > + BIT_ULL(VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK); > } > > static int mlx5_vdpa_set_driver_features(struct vdpa_device *vdev, u64 > features) > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c > b/drivers/vdpa/vdpa_sim/vdpa_sim.c > index 8cb1cc2ea139..253c7fb35ea0 100644 > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c > @@ -428,7 +428,8 @@ static u64 vdpasim_get_device_features(struct vdpa_device > *vdpa) > > static u64 vdpasim_get_backend_features(const struct vdpa_device *vdpa) > { > - return BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK); > + return BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK) | > + BIT_ULL(VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK); > } > > static int vdpasim_set_driver_features(struct vdpa_device *vdpa, u64 > features) > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 692564b1bcbb..67b3f49fa709 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -682,7 +682,8 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, > unsigned int cmd, > return -EFAULT; > if (idx >= vdpa->ngroups || s.num >= vdpa->nas) > return -EINVAL; > - if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_DRIVER_OK) > + if ((ops->get_status(vdpa) & VIRTIO_CONFIG_S_DRIVER_OK) && > + !vhost_backend_has_feature(vq, > VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK)) > return -EBUSY; > if (!ops->set_group_asid) > return -EOPNOTSUPP; > @@ -791,7 +792,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, > BIT_ULL(VHOST_BACKEND_F_IOTLB_PERSIST) | > BIT_ULL(VHOST_BACKEND_F_SUSPEND) | > BIT_ULL(VHOST_BACKEND_F_RESUME) | > - > BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK))) > + > BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK) | > + > BIT_ULL(VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK))) > return -EOPNOTSUPP; > if ((features & BIT_ULL(VHOST_BACKEND_F_SUSPEND)) && > !vhost_vdpa_can_suspend(v)) > @@ -805,6 +807,13 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, > if ((features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) && > !vhost_vdpa_has_desc_group(v)) > return -EOPNOTSUPP; Ouch to me here. By reading the errno manual: Nit: By reading errno(3): ENOTSUP - Operation not supported (POSIX.1-2001). EOPNOTSUPP - Operation not supported on socket (POSIX.1-2001). I picked the wrong constant even if they share the same errno value (by the same page of the manual). MST, is it worth changing it? > + if (features & > BIT_ULL(VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK)) { > + if (!(features & BIT_ULL(VHOST_BACKEND_F_IOTLB_ASID))) > + return -EINVAL; > + if (!(vhost_vdpa_get_backend_features(v) & > + > BIT_ULL(VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK))) > + return -EOPNOTSUPP; > + } > if ((features & BIT_ULL(VHOST_BACKEND_F_IOTLB_PERSIST)) && > !vhost_vdpa_has_persistent_map(v)) > return -EOPNOTSUPP; > diff --git a/include/uapi/linux/vhost_types.h > b/include/uapi/linux/vhost_types.h > index 1c39cc5f5a31..ec1ff8a2e260 100644 > --- a/include/uapi/linux/vhost_types.h > +++ b/include/uapi/linux/vhost_types.h > @@ -197,5 +197,9 @@ struct vhost_vdpa_iova_range { > #define VHOST_BACKEND_F_DESC_ASID 0x7 > /* IOTLB don't flush memory mapping across device reset */ > #define VHOST_BACKEND_F_IOTLB_PERSIST 0x8 > +/* Device supports changing the group ASID after DRIVER_OK. > + * Requires VHOST_BACKEND_F_IOTLB_ASID. > + */ > +#define VHOST_BACKEND_F_GROUP_ASID_AFTER_DRIVER_OK 0x9 > > #endif > -- > 2.54.0 >
