Re: [Qemu-devel] OSX guest vs. kvm ioapic polarity

[Gabriel L. Somlo]

On Wed, Jan 29, 2014 at 03:17:43PM +0100, Alexander Graf wrote:
> >Do you belive there's a chance we can work around this by just tweaking
> >ACPI on the QEMU side, and thus eliminate the need for a KVM patch ?
> 
> Yes, that's what I was hoping. What does the IRQ link property look
> like on a real Mac?

On the varous Mac models on which I pulled the DSDT, I have something
like:

                Device (LNKA) {
                    Name (_PRS, ResourceTemplate () {
                        IRQ (Level, ActiveLow, Shared, )
                            {1,3,4,5,6,7,10,12,14,15}
                    })

So yeah, definitely "Low", not "High".

Interestingly enough, on my Dell Latitude D630, the various LNK* nodes
also have "ActiveLow" in their _PRS methods! Same with my Dell R410
server.

> We define PCI IRQ links as
> 
>  254             Name(_PRS, ResourceTemplate() { \
>  255                 Interrupt(, Level, ActiveHigh, Shared) { \
>  256                     5, 10, 11 \
>  257                 } \
>  258             }) \
> 
> Have you tried to change this to ActiveLow?

Yes, and I also tried adding a bunch of extra IRQ numbers, but to no
avail. OS X will boot fine with the one-liner KVM patch removing the
statement:

    "irq_level ^= entry.fields.polarity;"

regardless of how LNK*._PRS is configured, and will hang without the
patch, also regardless of LNK*._PRS.

Thanks,
--G