Re: [Qemu-devel] [PATCH v4 05/11] suspend: add infrastructure

[Gerd Hoffmann]

  Hi,

>> I see.  I've expeced the the guest os putting them into a hlt loop or
>> some simliar idle state.  Play save and expliticly pausing them all is
>> certainly good from a robustness perspective.
> Yes. We should not trust a guest to do the "right thing".

Updated patch attached.

>>> I think it is also important to reset all device
>>> immediately to ensure that no device will do DMA into main memory after
>>> suspend.
>>
>> Didn't investigate yet, but I suspect this could break wakeup from pci
>> devices (nic, usb-tablet via uhci) ...
> 
> Yes. Can't say I fully understand how this works on real HW. I know
> that there are separate "power planes" for different system sates
> (this is defined in ACPI spec). So in S3 some devices (or even part of
> a device?) may be powered down, but others still have power. Not sure
> we should dive into emulating that in this patch series.

We'll do that later, one step at a time.

cheers,
  Gerd

0001-suspend-add-infrastructure.patch
Description: Text document