From: Will Deacon <will.deacon@arm.com>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org,
catalin.marinas@arm.com, mark.rutland@arm.com,
marc.zyngier@arm.com, kvmarm@lists.cs.columbia.edu,
Robert Ritcher <rritcher@cavium.com>,
Tirumalesh Chalamarla <tchalamarla@cavium.com>
Subject: Re: [PATCH v3 1/2] arm64: Add hypervisor safe helper for checking constant capabilities
Date: Tue, 8 Nov 2016 18:11:03 +0000 [thread overview]
Message-ID: <20161108181103.GM20591@arm.com> (raw)
In-Reply-To: <1478613381-5718-2-git-send-email-suzuki.poulose@arm.com>
On Tue, Nov 08, 2016 at 01:56:20PM +0000, Suzuki K Poulose wrote:
> The hypervisor may not have full access to the kernel data structures
> and hence cannot safely use cpus_have_cap() helper for checking the
> system capability. Add a safe helper for hypervisors to check a constant
> system capability, which *doesn't* fall back to checking the bitmap
> maintained by the kernel. With this, make the cpus_have_cap() only
> check the bitmask and force constant cap checks to use the new API
> for quicker checks.
>
> Cc: Robert Ritcher <rritcher@cavium.com>
> Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> arch/arm64/include/asm/cpufeature.h | 19 ++++++++++++-------
> arch/arm64/kernel/cpufeature.c | 2 +-
> arch/arm64/kernel/process.c | 2 +-
> drivers/irqchip/irq-gic-v3.c | 13 +------------
It might be worth having the GIC changes as a separate patch, but either
way:
Reviewed-by: Will Deacon <will.deacon@arm.com>
Will
next prev parent reply other threads:[~2016-11-08 18:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-08 13:56 [PATCH v3 0/2] arm64: Support systems without FP/ASIMD Suzuki K Poulose
2016-11-08 13:56 ` [PATCH v3 1/2] arm64: Add hypervisor safe helper for checking constant capabilities Suzuki K Poulose
2016-11-08 18:11 ` Will Deacon [this message]
2016-11-08 13:56 ` [PATCH v3 2/2] arm64: Support systems without FP/ASIMD Suzuki K Poulose
2016-11-14 11:48 ` Catalin Marinas
2016-11-15 10:42 ` Suzuki K Poulose
2016-11-11 13:41 ` [PATCH v3 0/2] " Marc Zyngier
2016-11-14 11:08 ` Catalin Marinas
2016-11-16 18:11 ` Catalin Marinas
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