[PATCH v1 1/2] drm/i915/gvt: reorder the shadow ppgtt update process by adding entry first

[Zhang, Tina]

> -----Original Message-----
> From: Zhenyu Wang [mailto:zhenyuw at linux.intel.com]
> Sent: Friday, May 5, 2017 10:46 AM
> To: Zhang, Tina <tina.zhang at intel.com>
> Cc: intel-gvt-dev at lists.freedesktop.org
> Subject: Re: [PATCH v1 1/2] drm/i915/gvt: reorder the shadow ppgtt update
> process by adding entry first
> 
> On 2017.05.04 17:35:09 +0800, Tina Zhang wrote:
> > Guest i915 driver may update the ppgtt table just before this workload
> > is going to be submitted to the hardware by device model. This case
> > wasn't handled well by device model before, due to the small time
> > window between removing old ppgtt entry and adding the new one. Errors
> > occur when the workload is executed by hardware during that small time
> > window. This patch is to remove this time window by adding the new
> > ppgtt entry first and then remove the old one.
> >
> 
> Although the fix logic seems sane, but could you elaborate the race case?
OK. I will add more about the race case.

> 
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