Re: [PATCH 00/31] KVM/MIPS: Implement hardware virtualization viathe MIPS-VZ extensions.

From: Ralf Baechle
Date: Fri Jun 14 2013 - 07:12:39 EST


On Fri, Jun 07, 2013 at 04:03:04PM -0700, David Daney wrote:

> Subject: [PATCH 00/31] KVM/MIPS: Implement hardware virtualization via the
> MIPS-VZ extensions.
>
> From: David Daney <david.daney@xxxxxxxxxx>
>
> These patches take a somewhat different approach to MIPS
> virtualization via the MIPS-VZ extensions than the patches previously
> sent by Sanjay Lal.
>
> Several facts about the code:
>
> o Existing exception handlers are modified to hook in to KVM instead
> of intercepting all exceptions via the EBase register, and then
> chaining to real exception handlers.
>
> o Able to boot 64-bit SMP guests that use the FPU (I have booted 4-way
> SMP 64-bit MIPS/Linux).
>
> o Additional overhead on every exception even when *no* vCPU is running.
>
> o Lower interrupt overhead, than the EBase interception method, when
> vCPU *is* running.
>
> o This code is somewhat smaller than the existing trap/emulate
> implementation (about 2100 lines vs. about 5300 lines)
>
> o Currently probably only usable on the OCTEON III CPU model, as some
> MIPS-VZ implementation-defined behaviors were assumed to have the
> OCTEON III behavior.
>
> Note: I think Ralf already has the 17/31 (MIPS: Quit exposing Kconfig
> symbols in uapi headers.) queued, but I also include it here.

Yes; as the references to CONFIG_* symbols in UAPI were a bug, I've
already merged this patch for 3.10 as 8f657933a3c2086d4731350c98f91a990783c0d3
[MIPS: Quit exposing Kconfig symbols in uapi headers.]

Ralf
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