Re: [Qemu-devel] [PATCH v1 1/3] sPAPR: Implement PCI error injection RTAS calls

[Alexander Graf]

> Am 23.06.2014 um 23:03 schrieb Benjamin Herrenschmidt <address@hidden>:
> 
>> On Mon, 2014-06-23 at 18:18 +0200, Alexander Graf wrote:
>> Device emulation code shouldn't even remotely have an idea what host 
>> it's running on. Also semantically there are a few issues with this approach
>> 
>>   1) QEMU is usually running with user privileges, so it doesn't have 
>> access to the file above
> 
> Right, this needs to go via VFIO like the rest of the EEH stuff
> 
>>   2) QEMU's channel to hardware devices is via normal kernel API. For 
>> physical devices that's VFIO. No side channels please.
> 
> Indeed. If the user gets access to that file, suddenly qemu can
> "manufacture" a bad string and error inject in other devices it doesn't
> own which isn't great.
> 
> Gavin, this needs to go via the same path as normal EEH and be limited
> to injecting errors that are completely bounded to the PE.
> 
> I don't think this is very high priority. We should first write a good
> host side error injection tool and sort out the reporting of the EEH log
> from host to guest.
> 
>>   3) Ownership of the question whether a PE is in error mode is 
>> responsibility of the PHB. In the emulated case, the PHB would have to 
>> set itself into a mode where it behaves as if it's blocked.
> 
> We don't have to support error injection for emulated since we don't
> support (yet) the rest oF EEH for them. We could one day but it's
> really not urgent.

I agree, but the layers are the same ;)

Alex

> 
> Cheers,
> Ben.
> 
>