Re: [Qemu-devel] [PATCH] vfio/pci-quirks: Set non-zero GMS memory size for IGD

[Dmitry Fleytman]

> On 2 Aug 2017, at 24:24 AM, Alex Williamson <address@hidden> wrote:
> 
> On Fri, 28 Jul 2017 08:22:45 +0300
> Dmitry Fleytman <address@hidden <mailto:address@hidden>> wrote:
> 
>>> On 28 Jul 2017, at 07:51 AM, Zhang, Xiong Y <address@hidden> wrote:
>>> 
>>>>> On 26 Jul 2017, at 08:22 AM, Zhang, Xiong Y <address@hidden>  
>>>> wrote:  
>>>>> 
>>>>> Sorry, we indeed found Intel windows guest graphic driver couldn't be 
>>>>> bind  
>>>> when GMS memory size is zero. And we have fixed it and the next intel
>>>> windows driver release will contain this fix.  
>>>>> So currently please use x-igd-gms in legacy mode to work around this.
>>>>> 
>>>>> BTW, how did you know window driver allocate extra ~4G memory when  
>>>> GMS size set to 0 ?
>>>> 
>>>> We noticed that with new IGD driver memory usage on VMs raised by around
>>>> 4G.
>>>> 
>>>> Then we examined memory allocations with poolmon
>>>> (https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/poolm
>>>> on)
>>>> and saw that around 4G of memory is allocated with IGD driver pool tag.
>>>> Additionally we noticed that on VMs with less than 5G of memory IGD driver
>>>> does not load and system does fallback to standard VGA driver.
>>>> 
>>> [Zhang, Xiong Y]  I tried our internal driver and didn't found the above 
>>> two issues, please wait for the next intel graphic driver release.  
>> 
>> Thanks!
> 
> So to close on this, we should just be recommending that users
> encountering this problem add the x-igd-gms=1 option to the device
> until the next Intel graphics release.  I won't plan to push this
> change.  Thanks all,

Hi Alex,

Agree, that makes sense.

Thanks you,
Dmitry

> 
> Alex