Re: Device Reset on Nvidia GPUs

[Gordan Bobic <gordan@bobich.net>]

 On Fri, 15 Nov 2013 14:27:21 +0000, Stefano Stabellini 
 <stefano.stabellini@eu.citrix.com> wrote:
> On Fri, 15 Nov 2013, Gordan Bobic wrote:
>> I've noticed that nouveau driver has a sysfs reset implemented
>> (although I'm not sure whether it is just a stub or whether it
>> does anything).
>>
>> Now, I fully understand that this is not actually necessary,
>> based purely on empirical evidence:
>>
>> My ATI cards reliably crash the host when the domU the are passed
>> to is rebooted, and the xen-pciback driver does have the sysfs
>> reset implemented for ATI cards.
>>
>> OTOH, my (modified) Nvidia cards handle domU reboots perfectly
>> and the xen-pciback driver has no sysfs reset implementation
>> for those.
>>
>> So I'm kind of torn between:
>> 1) It's not broken so don't even think about trying to fix it.
>> 2) Since FOSS reset implementation seems to exist, it might be
>> handy to port it into the xen-pciback feature list (caveat:
>> this may impact 1), which would be embarrasing).
>>
>> Thoughts?
>
> libxl is capable of using the sysfs reset node, so there shouldn't be
> any needed for porting the reset code to pciback

 Not quite - when the device is owned by xen-pciback, there is
 no reset node. When it is owned by nouveau, the reset node in
 sysfs is there.

 Gordan