[PATCH] drm/i915/gvt: initialize dmabuf mutex in vgpu_create

[Hang Yuan]

On 07/31/2018 10:39 AM, Zhenyu Wang wrote:
> On 2018.07.30 10:52:53 +0800, intel-gvt-dev-bounces at lists.freedesktop.org wrote:
>> From: Hang Yuan <hang.yuan at linux.intel.com>
>>
>> Currently, the mutex used in GVT dmabuf support is not initialized until
>> vgpu device is opened. If one vgpu device is opened and then removed, the
>> mutex will be used in vgpu remove operation without initialization. This
>> patch initializes the mutex in vgpu create operation to avoid the problem.
>>
> 
> Good catch! Looks fine to me. Pls still think about adding stable kernel in cc
> for this kind of fixes, definitely fit for stable kernel with proper version.
> 
> Reviewed-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> 
> thanks!
The bug doesn't cause any oops or other critical issues, even no any 
warning message in latest gvt branch kernel. So I didn't copy stable kernel.

Thanks,
Henry

>> Fixes: e546e281d33d("drm/i915/gvt: Dmabuf support for GVT-g")
>> Signed-off-by: Hang Yuan <hang.yuan at linux.intel.com>
>> ---
>>   drivers/gpu/drm/i915/gvt/kvmgt.c | 1 -
>>   drivers/gpu/drm/i915/gvt/vgpu.c  | 1 +
>>   2 files changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
>> index a22d539..cbdf915e 100644
>> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
>> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
>> @@ -1615,7 +1615,6 @@ static int kvmgt_guest_init(struct mdev_device *mdev)
>>   	kvmgt_protect_table_init(info);
>>   	gvt_cache_init(vgpu);
>>   
>> -	mutex_init(&vgpu->dmabuf_lock);
>>   	init_completion(&vgpu->vblank_done);
>>   
>>   	info->track_node.track_write = kvmgt_page_track_write;
>> diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
>> index f6fa916..0bc1f1e 100644
>> --- a/drivers/gpu/drm/i915/gvt/vgpu.c
>> +++ b/drivers/gpu/drm/i915/gvt/vgpu.c
>> @@ -361,6 +361,7 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
>>   	vgpu->gvt = gvt;
>>   	vgpu->sched_ctl.weight = param->weight;
>>   	mutex_init(&vgpu->vgpu_lock);
>> +	mutex_init(&vgpu->dmabuf_lock);
>>   	INIT_LIST_HEAD(&vgpu->dmabuf_obj_list_head);
>>   	INIT_RADIX_TREE(&vgpu->page_track_tree, GFP_KERNEL);
>>   	idr_init(&vgpu->object_idr);
>> -- 
>> 2.7.4
>>
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