Re: [PATCH] KVM: Don't mistreat edge-triggered INIT IPI as INIT de-assert. (LAPIC)

[Julian Stecklina <js@alien8.de>]

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On Fr, 2011-12-23 at 08:40 -0200, Marcelo Tosatti wrote:
> On Mon, Dec 19, 2011 at 02:14:27AM +0100, Julian Stecklina wrote:
> > If the guest programs an IPI with level=0 (de-assert) and trig_mode=0 (edge),
> > it is erroneously treated as INIT de-assert and ignored, but to quote the
> > spec: "For this delivery mode [INIT de-assert], the level flag must be set to
> > 0 and trigger mode flag to 1."
> 
> Yes, the implementation ignores INIT de-assert. Quoting the spec:
> 
> "(INIT Level De-assert) (Not supported in the Pentium 4 and Intel Xeon
> processors.)"
> 
> Your patch below is not improving the implementation to be closer to the
> spec: it'll trigger the INIT state initialization with trig_mode == 0
> (which is not in accordance with your spec quote above).

I think our code that triggers this does weird things. Let me check
that. Until then ignore that patch and sorry for the noise. :) At least
it seems as if real hardware is interpreting the spec in a slightly
different way...

Regards, Julian


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