Messages in this thread | | | Date | Wed, 23 Jun 2010 18:35:55 +0300 | From | Avi Kivity <> | Subject | Re: [PATCH for-2.6.35] virtio-pci: disable msi at startup |
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On 06/23/2010 06:26 PM, Michael S. Tsirkin wrote: > > >>> >>> >>>>>> Shouldn't a reset be equivalent to power cycling? >>>>>> >>>>>> >>>>>> >>>>> If we did this, driver would need to restore registers >>>>> such as BAR etc. >>>>> >>>>> >>>>> >>>> We could save/restore the registers we care about. >>>> >>>> >>> It seems easier to clear registers we care about. >>> >> We know the registers we care about, we don't know the ones we don't. >> > If/when we use more registers, we can update driver to clear them on start. >
The kdump kernel may not load drivers for those extra devices.
>> I'm talking about FLRing all cards, not just those you want to use. >> > reset using FLR/PM is complex because of the need to save/restore > config space. Doing this on a crashing kernel sounds scary. >
Well, you only need to save/restore for the devices you use. The rest you reset and forget.
I don't really see why copying some config space is crazy.
>>> It's also too late >>> now: changing behaviour will break old drivers. >>> >>> >> Why? the FLR is triggered by the guest kernel, so all drivers will be >> aware it was FLRed. >> > Not for FLR. Too late to reset on PA write. > >
What's PA write?
-- error compiling committee.c: too many arguments to function
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