From: Will Deacon <will.deacon@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
catalin.marinas@arm.com, christoffer.dall@arm.com,
drjones@redhat.com, marc.zyngier@arm.com,
ramana.radhakrishnan@arm.com, awallis@codeaurora.org
Subject: Re: [PATCHv4 05/10] arm64/cpufeature: detect pointer authentication
Date: Wed, 4 Jul 2018 17:09:09 +0100 [thread overview]
Message-ID: <20180704160909.GR4828@arm.com> (raw)
In-Reply-To: <20180525100137.mte5z2sonob3vffq@lakrids.cambridge.arm.com>
On Fri, May 25, 2018 at 11:01:37AM +0100, Mark Rutland wrote:
> On Wed, May 23, 2018 at 09:48:28AM +0100, Suzuki K Poulose wrote:
> > On 03/05/18 14:20, Mark Rutland wrote:
> > > diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
> > > index bc51b72fafd4..9dcb4d1b14f5 100644
> > > --- a/arch/arm64/include/asm/cpucaps.h
> > > +++ b/arch/arm64/include/asm/cpucaps.h
> > > @@ -48,7 +48,10 @@
> > > #define ARM64_HAS_CACHE_IDC 27
> > > #define ARM64_HAS_CACHE_DIC 28
> > > #define ARM64_HW_DBM 29
> > > +#define ARM64_HAS_ADDRESS_AUTH_ARCH 30
> > > +#define ARM64_HAS_ADDRESS_AUTH_IMP_DEF 31
> >
> > Where are these caps used ? I couldn't find anything in the series
> > that uses them. Otherwise looks good to me.
>
> Those were consumed by KVM support, which needed to detect if CPUs had
> mismatched support. Currently they're just placeholders as I need a
> cpucap value for the separate IMP-DEF / architected probing cases.
>
> I *could* get rid of those and just have the ARM64_HAS_ADDRESS_AUTH case
> log "Address authentication", but I wanted to have separate messages for
> IMP-DEF vs architected.
Why? Surely it only matters if we find a mixture, and then you'll shout
loudly. I'd certainly be in favour of reducing the number of caps you're
adding here, particularly if they're just there for a line in dmesg.
Will
next prev parent reply other threads:[~2018-07-04 16:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-03 13:20 [PATCHv4 00/10] ARMv8.3 pointer authentication userspace support Mark Rutland
2018-05-03 13:20 ` [PATCHv4 01/10] arm64: add pointer authentication register bits Mark Rutland
2018-05-03 13:20 ` [PATCHv4 02/10] arm64/kvm: consistently handle host HCR_EL2 flags Mark Rutland
2018-05-03 13:20 ` [PATCHv4 03/10] arm64/kvm: hide ptrauth from guests Mark Rutland
2018-05-03 13:20 ` [PATCHv4 04/10] arm64: Don't trap host pointer auth use to EL2 Mark Rutland
2018-05-03 13:20 ` [PATCHv4 05/10] arm64/cpufeature: detect pointer authentication Mark Rutland
2018-05-23 8:48 ` Suzuki K Poulose
2018-05-25 10:01 ` Mark Rutland
2018-07-04 16:09 ` Will Deacon [this message]
2018-05-03 13:20 ` [PATCHv4 06/10] arm64: add basic pointer authentication support Mark Rutland
2018-05-22 19:08 ` Adam Wallis
2018-05-23 8:42 ` Suzuki K Poulose
2018-05-25 10:18 ` Mark Rutland
2018-06-08 13:11 ` Kristina Martsenko
2018-05-03 13:20 ` [PATCHv4 07/10] arm64: expose user PAC bit positions via ptrace Mark Rutland
2018-05-03 13:20 ` [PATCHv4 08/10] arm64: perf: strip PAC when unwinding userspace Mark Rutland
2018-05-03 13:20 ` [PATCHv4 09/10] arm64: enable pointer authentication Mark Rutland
2018-05-03 13:20 ` [PATCHv4 10/10] arm64: docs: document " Mark Rutland
2018-07-04 16:12 ` [PATCHv4 00/10] ARMv8.3 pointer authentication userspace support Will Deacon
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