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Re: [Qemu-devel] [PATCH v1 1/3] sPAPR: Implement PCI error injection RTA
From: |
Gavin Shan |
Subject: |
Re: [Qemu-devel] [PATCH v1 1/3] sPAPR: Implement PCI error injection RTAS calls |
Date: |
Tue, 24 Jun 2014 10:14:05 +1000 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Mon, Jun 23, 2014 at 11:13:45PM +0200, Alexander Graf wrote:
>
>> 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 ;)
>
Thanks, Ben and Alex. Yes, it's fair enough for VFIO (ioctl cmd) to
routing the PCI error injection.
Thanks,
Gavin
>Alex
>
>>
>> Cheers,
>> Ben.
>>