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From:   Raghavendra Rao Ananta <rananta@google.com>
Date:   Thu, 2 Sep 2021 10:55:08 -0700
Message-ID: <CAJHc60xLj77n3pvqQNn_+LoLL=UZtQV+hz3r4VmPpqpZ7SBPVg@mail.gmail.com>
Subject: Re: [PATCH v3 02/12] KVM: arm64: selftests: Add write_sysreg_s and read_sysreg_s
To:     Andrew Jones <drjones@redhat.com>
Cc:     Oliver Upton <oupton@google.com>, kvm@vger.kernel.org,
        Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Peter Shier <pshier@google.com>, linux-kernel@vger.kernel.org,
        Marc Zyngier <maz@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org
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On Thu, Sep 2, 2021 at 5:31 AM Andrew Jones <drjones@redhat.com> wrote:
>
> On Wed, Sep 01, 2021 at 11:06:10PM +0000, Oliver Upton wrote:
> > On Wed, Sep 01, 2021 at 03:48:40PM -0700, Raghavendra Rao Ananta wrote:
> > > On Wed, Sep 1, 2021 at 3:08 PM Oliver Upton <oupton@google.com> wrote:
> > > >
> > > > On Wed, Sep 01, 2021 at 09:28:28PM +0000, Oliver Upton wrote:
> > > > > On Wed, Sep 01, 2021 at 09:14:02PM +0000, Raghavendra Rao Ananta wrote:
> > > > > > For register names that are unsupported by the assembler or the ones
> > > > > > without architectural names, add the macros write_sysreg_s and
> > > > > > read_sysreg_s to support them.
> > > > > >
> > > > > > The functionality is derived from kvm-unit-tests and kernel's
> > > > > > arch/arm64/include/asm/sysreg.h.
> > > > > >
> > > > > > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> > > > >
> > > > > Would it be possible to just include <asm/sysreg.h>? See
> > > > > tools/arch/arm64/include/asm/sysreg.h
> > > >
> > > > Geez, sorry for the noise. I mistakenly searched from the root of my
> > > > repository, not the tools/ directory.
> > > >
> > > No worries :)
> > >
> > > > In any case, you could perhaps just drop the kernel header there just to
> > > > use the exact same source for kernel and selftest.
> > > >
> > > You mean just copy/paste the entire header? There's a lot of stuff in
> > > there which we
> > > don't need it (yet).
> >
> > Right. It's mostly register definitions, which I don't think is too high
> > of an overhead. Don't know where others stand, but I would prefer a
> > header that is equivalent between kernel & selftests over a concise
> > header.
> >
>
> Until now we haven't needed the sys_reg(...) type of definitions for
> sysregs in selftests. In case we did, we defined the registers we
> needed for get/set_one_reg by their parts, e.g.
>
>  #define ID_AA64DFR0_EL1 3, 0,  0, 5, 0
>
> allowing us to choose how we use them, ARM64_SYS_REG(...) vs.
> sys_reg(...).
>
> Bringing over sysreg.h is probably a good idea though. If we do, then
> I'd suggest we define a new macro that allows us to convert a SYS_*
> register definition from sysreg.h into an ARM64_SYS_REG definition
> for get/set_one_reg in order to avoid redundant definitions.
>

I agree. Will look into it, and plan to pull the original sysreg.h
into selftests.

Regards,
Raghavendra

> Thanks,
> drew
>