[PATCH 2/3] KVM: arm/arm64: Add ARM arch timer interrupts ABI

Christoffer Dall christoffer.dall at linaro.org
Tue Nov 1 08:32:32 PDT 2016


On Tue, Nov 01, 2016 at 02:54:11PM +0000, Peter Maydell wrote:
> On 1 November 2016 at 14:50, Christoffer Dall
> <christoffer.dall at linaro.org> wrote:
> > On Tue, Nov 01, 2016 at 11:26:54AM +0000, Peter Maydell wrote:
> >> Possible current and future outbound interrupt lines (some of these
> >> would only show up in some unlikely or lots-of-implementation-needed
> >> cases, I'm just trying to produce an exhaustive list):
> >>  * virtual timer
> >>  * physical timer
> >>  * hyp timer (nested virtualization case)
> >>  * secure timer (unlikely but maybe if EL3 is ever supported inside a VM)
> >>  * gic maintenance interrupt (nested virt again)
> >>  * PMU interrupt
> >
> > Thanks for the list, that's good to have around for the future.
> >
> > There's also the potential of the EL2 virtual timer for nested VHE
> > support, right?
> 
> That's the one I meant by "hyp timer".
> 

there's the hyp timer, and then there's the ARMv8.1 virtual hyp timer.

> >> The kernel doesn't know which interrupt number these would be wired
> >> up to, so they're all just arbitrary outputs, and you could put them
> >> in one field or split them up into multiple fields, it doesn't make
> >> much difference.
> >>
> >
> > So if we keep this we're kind of suggesting that we'll have a field per
> > device type later on.  Since this is a u8 and we are talking about up 5
> > 5 timers already,
> 
> 4.
> 

virtual
physical
hyp
virtual hyp
secure

Am I missing something?

-Christoffer



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