[PATCH 1/2] drm/i915/gvt: Release gvt->lock at the failure of finding page track

[Zhenyu Wang]

On 2018.03.05 06:01:43 +0000, Wang, Zhi A wrote:
> Do you wish this patch going to gvt-fixes? :)
>

As this is to fix recent page track rework, so should be for gvt-next.

> -----Original Message-----
> From: intel-gvt-dev [mailto:intel-gvt-dev-bounces at lists.freedesktop.org] On Behalf Of Xiong Zhang
> Sent: Tuesday, March 6, 2018 6:07 AM
> To: intel-gvt-dev at lists.freedesktop.org
> Cc: Zhang, Xiong Y <xiong.y.zhang at intel.com>
> Subject: [PATCH 1/2] drm/i915/gvt: Release gvt->lock at the failure of finding page track
> 
> page_track_handler take lock at the beginning, the lock should be released at the failure of finding page track. Otherwise deadlock will happen.
> 
> Fixes:7772c6f723e1("drm/i915/gvt:Provide generic page_track in infrastructure for write_protected page")
> Signed-off-by: Xiong Zhang <xiong.y.zhang at intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/page_track.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/page_track.c b/drivers/gpu/drm/i915/gvt/page_track.c
> index 09bd56e..2d03054 100644
> --- a/drivers/gpu/drm/i915/gvt/page_track.c
> +++ b/drivers/gpu/drm/i915/gvt/page_track.c
> @@ -165,7 +165,7 @@ int intel_vgpu_page_track_handler(struct intel_vgpu *vgpu, u64 gpa,
>  
>  	page_track = intel_vgpu_find_page_track(vgpu, gpa >> PAGE_SHIFT);
>  	if (!page_track)
> -		return 0;
> +		goto out;
>  
>  	if (unlikely(vgpu->failsafe)) {
>  		/* Remove write protection to prevent furture traps. */ @@ -176,6 +176,7 @@ int intel_vgpu_page_track_handler(struct intel_vgpu *vgpu, u64 gpa,
>  			gvt_err("guest page write error, gpa %llx\n", gpa);
>  	}
>  
> +out:
>  	mutex_unlock(&gvt->lock);
>  	return ret;
>  }

nice catch, thx!

-- 
Open Source Technology Center, Intel ltd.

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