[PATCH 2/6] arm64: Convert hcalls to use HVC immediate value

[Timur Tabi]

On Thu, Mar 19, 2015 at 3:35 PM, Geoff Levand <geoff at infradead.org> wrote:
> The existing arm64 hcall implementations are limited in that they only allow
> for two distinct hcalls; with the x0 register either zero or not zero.  Also,
> the API of the hyp-stub exception vector routines and the KVM exception vector
> routines differ; hyp-stub uses a non-zero value in x0 to implement
> __hyp_set_vectors, whereas KVM uses it to implement kvm_call_hyp.
>
> To allow for additional hcalls to be defined and to make the arm64 hcall API
> more consistent across exception vector routines, change the hcall
> implementations to use the 16 bit immediate value of the HVC instruction to
> specify the hcall type.
>
> Define three new preprocessor macros HVC_CALL_HYP, HVC_GET_VECTORS, and
> HVC_SET_VECTORS to be used as hcall type specifiers and convert the
> existing __hyp_get_vectors(), __hyp_set_vectors() and kvm_call_hyp() routines
> to use these new macros when executing an HVC call.  Also, change the
> corresponding hyp-stub and KVM el1_sync exception vector routines to use these
> new macros.
>
> Signed-off-by: Geoff Levand <geoff at infradead.org>

What is the status of this patch?  I see it's not in 4.2.  I ask
because this patch might be breaking our 4.2-based kernel, and I'm
just wondering if it's still applicable.

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