[PATCH 0/2] arm64: KVM: Use instruction patching for GIC world switch

Catalin Marinas catalin.marinas at arm.com
Fri Jun 12 07:12:55 PDT 2015

On Fri, Jun 12, 2015 at 12:06:35PM +0100, Marc Zyngier wrote:
> The current way we deal with the GIC world switch on arm64 is a bit
> convoluted. As we have two possible backends, we rely on a couple of
> indirections set at boot time. These indirection never change, so it
> would make more sense to directly patch in a branch to the right
> function.
> To do this, we introduce a new CPU feature that detect the presence of
> a GICv3 CPU interface. When detected, we patch branches to the GICv3
> save/restore functions that otherwise point to the GICv2 backend.
> Tested on both GICv2 (Juno, Seattle) and GICv3 (FVP Base model).
> These patches have been on the various lists for quite a while as part
> of a series dealing with instruction patching. Now that the
> prerequisite are queued for 4.2, it would make sense for these to be
> merged alongside.
> Catalin, would you mind taking them through the arm64 tree?
> Marc Zyngier (2):
>   arm64: alternative: Introduce feature for GICv3 CPU interface
>   arm64: KVM: Switch vgic save/restore to alternative_insn

Applied. Thanks.


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