Messages in this thread | | | From | Sami Tolvanen <> | Date | Mon, 4 Nov 2019 13:44:30 -0800 | Subject | Re: [PATCH v4 03/17] arm64: kvm: stop treating register x18 as caller save |
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On Mon, Nov 4, 2019 at 3:51 AM Mark Rutland <mark.rutland@arm.com> wrote: > > --- a/arch/arm64/kvm/hyp/entry.S > > +++ b/arch/arm64/kvm/hyp/entry.S > > @@ -23,6 +23,7 @@ > > .pushsection .hyp.text, "ax" > > > > Could we please add a note here, e.g. > > /* > * We treat x18 as callee-saved as the host may use it as a platform > * register (e.g. for shadow call stack). > */ > > ... as that will avoid anyone trying to optimize this away in future > after reading the AAPCS.
Sure, that's a good idea.
> > .macro restore_callee_saved_regs ctxt > > + // We assume \ctxt is not x18-x28 > > Probably worth s/assume/require/ here.
Agreed, I'll change this in v5.
Sami
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