Re: Reset problem vs. MMIO emulation, hypercalls, etc...

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2012-08-07 at 16:13 +0300, Avi Kivity wrote:
> 

> Peter has started to fix up this naming mess in qemu.  I guess we should
> do the same for the kernel (except for ABIs) and document it, because it
> keeps generating confusion. 

Ok so our current situation is that the XICS and MPIC are emulated in
userspace entirely but the link between them and the VCPU is the
asynchronous EE line so we are fine.

I'm currently working on moving the XICS into the kernel for performance
reasons, however, just like ARM VGIC, I can't seem to find a way to
"fit" in the "generic" irqchip code in there. It's just not generic at
all and quite x86 centric :-)

So for now I'm just doing my own version of CREATE_IRQCHIP to create it
and KVM_INTERRUPT to trigger the various interrupts. None of the mapping
stuff (which we really don't need).

That's a bit of a problem vs. some of the code qemu-side such as in
virtio-pci which does seem to be written around the model exposed by the
x86 stuff and relies on doing such mappings so I think we'll have to
butcher some of that.

Cheers,
Ben.