[kvmarm] [PATCH v2 08/10] ARM: KVM: VGIC initialisation code

Peter Maydell peter.maydell at linaro.org
Tue Oct 2 15:45:54 EDT 2012

On 2 October 2012 20:28, Will Deacon <will.deacon at arm.com> wrote:
> On Tue, Oct 02, 2012 at 07:31:43PM +0100, Peter Maydell wrote:
>> We probably want to be passing in the "base of the cpu-internal
>> peripherals", rather than "base of the GIC" specifically. For the
>> A15 these are the same thing, but that's not inherent [compare the
>> A9 which has more devices at fixed offsets from a configurable
>> base address].
> If you do that, userspace will need a way to probe the emulated CPU so
> that is knows exactly which set of peripherals there are and which ones it
> needs to emulate. This feels pretty nasty, given that the vgic is handled
> more or less completely by the kernel-side of things.

Userspace knows what the emulated CPU is because it tells the
kernel which CPU to provide -- the kernel can say "yes" or "no" but
it can't provide a different CPU to the one we ask for, or
one with bits mising...

-- PMM

More information about the linux-arm-kernel mailing list