drm/amdgpu: Forward VMID reservation errors

[ Upstream commit 8defb4f ]

Otherwise userspace may be fooled into believing it has a reserved VMID
when in reality it doesn't, ultimately leading to GPU hangs when SPM is
used.

Fixes: 80e709e ("drm/amdgpu: add option params to enforce process isolation between graphics and compute")
Cc: stable@vger.kernel.org
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Natalie Vock <natalie.vock@gmx.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[ adapted 3-argument amdgpu_vmid_alloc_reserved(adev, vm, vmhub) call to 2-argument version and added separate error check to preserve reserved_vmid tracking logic. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: pixelcluster

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -2747,10 +2747,12 @@ int amdgpu_vm_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	case AMDGPU_VM_OP_RESERVE_VMID:
 		/* We only have requirement to reserve vmid from gfxhub */
 		if (!fpriv->vm.reserved_vmid[AMDGPU_GFXHUB(0)]) {
-			amdgpu_vmid_alloc_reserved(adev, AMDGPU_GFXHUB(0));
+			int r = amdgpu_vmid_alloc_reserved(adev, AMDGPU_GFXHUB(0));
+
+			if (r)
+				return r;
 			fpriv->vm.reserved_vmid[AMDGPU_GFXHUB(0)] = true;
 		}
-
 		break;
 	case AMDGPU_VM_OP_UNRESERVE_VMID:
 		if (fpriv->vm.reserved_vmid[AMDGPU_GFXHUB(0)]) {