drm/amdgpu: Forward VMID reservation errors

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>

Author: pixelcluster

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

@@ -2916,8 +2916,7 @@ int amdgpu_vm_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	switch (args->in.op) {
 	case AMDGPU_VM_OP_RESERVE_VMID:
 		/* We only have requirement to reserve vmid from gfxhub */
-		amdgpu_vmid_alloc_reserved(adev, vm, AMDGPU_GFXHUB(0));
-		break;
+		return amdgpu_vmid_alloc_reserved(adev, vm, AMDGPU_GFXHUB(0));
 	case AMDGPU_VM_OP_UNRESERVE_VMID:
 		amdgpu_vmid_free_reserved(adev, vm, AMDGPU_GFXHUB(0));
 		break;