Re: [PATCH v4 5/7] drm/i915/gvt: Change from vfio_group_(un)pin_pages to vfio_(un)pin_pages

["Wang, Zhi A" <zhi.a.wang@intel.com>]

On 5/6/22 12:08 AM, Jason Gunthorpe wrote:
> Use the existing vfio_device versions of vfio_(un)pin_pages(). There is no
> reason to use a group interface here, kvmgt has easy access to a
> vfio_device.
> 
> Delete kvmgt_vdev::vfio_group since these calls were the last users.
> 
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/gpu/drm/i915/gvt/gvt.h   |  1 -
>  drivers/gpu/drm/i915/gvt/kvmgt.c | 27 ++++++---------------------
>  2 files changed, 6 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
> index 5a28ee965b7f3e..2af4c83e733c6c 100644
> --- a/drivers/gpu/drm/i915/gvt/gvt.h
> +++ b/drivers/gpu/drm/i915/gvt/gvt.h
> @@ -231,7 +231,6 @@ struct intel_vgpu {
>  	struct kvm *kvm;
>  	struct work_struct release_work;
>  	atomic_t released;
> -	struct vfio_group *vfio_group;
>  
>  	struct kvm_page_track_notifier_node track_node;
>  #define NR_BKT (1 << 18)
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 1cec4f1fdfaced..7655ffa97d5116 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -243,7 +243,7 @@ static void gvt_unpin_guest_page(struct intel_vgpu *vgpu, unsigned long gfn,
>  	for (npage = 0; npage < total_pages; npage++) {
>  		unsigned long cur_gfn = gfn + npage;
>  
> -		ret = vfio_group_unpin_pages(vgpu->vfio_group, &cur_gfn, 1);
> +		ret = vfio_unpin_pages(&vgpu->vfio_device, &cur_gfn, 1);
>  		drm_WARN_ON(&i915->drm, ret != 1);
>  	}
>  }
> @@ -266,8 +266,8 @@ static int gvt_pin_guest_page(struct intel_vgpu *vgpu, unsigned long gfn,
>  		unsigned long cur_gfn = gfn + npage;
>  		unsigned long pfn;
>  
> -		ret = vfio_group_pin_pages(vgpu->vfio_group, &cur_gfn, 1,
> -					   IOMMU_READ | IOMMU_WRITE, &pfn);
> +		ret = vfio_pin_pages(&vgpu->vfio_device, &cur_gfn, 1,
> +				     IOMMU_READ | IOMMU_WRITE, &pfn);
>  		if (ret != 1) {
>  			gvt_vgpu_err("vfio_pin_pages failed for gfn 0x%lx, ret %d\n",
>  				     cur_gfn, ret);
> @@ -804,7 +804,6 @@ static int intel_vgpu_open_device(struct vfio_device *vfio_dev)
>  	struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
>  	unsigned long events;
>  	int ret;
> -	struct vfio_group *vfio_group;
>  
>  	vgpu->iommu_notifier.notifier_call = intel_vgpu_iommu_notifier;
>  	vgpu->group_notifier.notifier_call = intel_vgpu_group_notifier;
> @@ -827,28 +826,19 @@ static int intel_vgpu_open_device(struct vfio_device *vfio_dev)
>  		goto undo_iommu;
>  	}
>  
> -	vfio_group =
> -		vfio_group_get_external_user_from_dev(vgpu->vfio_device.dev);
> -	if (IS_ERR_OR_NULL(vfio_group)) {
> -		ret = !vfio_group ? -EFAULT : PTR_ERR(vfio_group);
> -		gvt_vgpu_err("vfio_group_get_external_user_from_dev failed\n");
> -		goto undo_register;
> -	}
> -	vgpu->vfio_group = vfio_group;
> -
>  	ret = -EEXIST;
>  	if (vgpu->attached)
> -		goto undo_group;
> +		goto undo_register;
>  
>  	ret = -ESRCH;
>  	if (!vgpu->kvm || vgpu->kvm->mm != current->mm) {
>  		gvt_vgpu_err("KVM is required to use Intel vGPU\n");
> -		goto undo_group;
> +		goto undo_register;
>  	}
>  
>  	ret = -EEXIST;
>  	if (__kvmgt_vgpu_exist(vgpu))
> -		goto undo_group;
> +		goto undo_register;
>  
>  	vgpu->attached = true;
>  	kvm_get_kvm(vgpu->kvm);
> @@ -868,10 +858,6 @@ static int intel_vgpu_open_device(struct vfio_device *vfio_dev)
>  	atomic_set(&vgpu->released, 0);
>  	return 0;
>  
> -undo_group:
> -	vfio_group_put_external_user(vgpu->vfio_group);
> -	vgpu->vfio_group = NULL;
> -
>  undo_register:
>  	vfio_unregister_notifier(vfio_dev, VFIO_GROUP_NOTIFY,
>  				 &vgpu->group_notifier);
> @@ -925,7 +911,6 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
>  	gvt_cache_destroy(vgpu);
>  
>  	intel_vgpu_release_msi_eventfd_ctx(vgpu);
> -	vfio_group_put_external_user(vgpu->vfio_group);
>  
>  	vgpu->kvm = NULL;
>  	vgpu->attached = false;
> 
Acked-by: Zhi Wang <zhi.a.wang@intel.com>