Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752349AbbGIJ7t (ORCPT ); Thu, 9 Jul 2015 05:59:49 -0400 Received: from foss.arm.com ([217.140.101.70]:45213 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751508AbbGIJ7l (ORCPT ); Thu, 9 Jul 2015 05:59:41 -0400 Message-ID: <559E4608.5090102@arm.com> Date: Thu, 09 Jul 2015 10:59:36 +0100 From: Marc Zyngier Organization: ARM Ltd User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: Mark Rutland CC: Catalin Marinas , Will Deacon , Christoffer Dall , "kvmarm@lists.cs.columbia.edu" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "kvm@vger.kernel.org" Subject: Re: [PATCH 03/13] arm64: Add ARM64_HAS_VIRT_HOST_EXTN feature References: <1436372356-30410-1-git-send-email-marc.zyngier@arm.com> <1436372356-30410-4-git-send-email-marc.zyngier@arm.com> <20150709094818.GB20105@leverpostej> In-Reply-To: <20150709094818.GB20105@leverpostej> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3021 Lines: 98 On 09/07/15 10:48, Mark Rutland wrote: > On Wed, Jul 08, 2015 at 05:19:06PM +0100, Marc Zyngier wrote: >> Add a new ARM64_HAS_VIRT_HOST_EXTN features to indicate that the >> CPU has the ARMv8,1 VHE capability. > > Nit: s/,/./ > > It's probably worth mentioning somewhere that we have to check CurrentEL > rather than a feature register in case some prior software dropped us to > EL1N (e.g. if we're a guest under this scheme). Good point, this is a leftover from a previous version that actually checked the feature register. I'll clean up the commit log. Thanks, M. > Mark. > >> >> This will be used to trigger kernel patching in KVM. >> >> Signed-off-by: Marc Zyngier >> --- >> arch/arm64/include/asm/cpufeature.h | 3 ++- >> arch/arm64/kernel/cpufeature.c | 11 +++++++++++ >> 2 files changed, 13 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h >> index c104421..6c3742d 100644 >> --- a/arch/arm64/include/asm/cpufeature.h >> +++ b/arch/arm64/include/asm/cpufeature.h >> @@ -25,8 +25,9 @@ >> #define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1 >> #define ARM64_WORKAROUND_845719 2 >> #define ARM64_HAS_SYSREG_GIC_CPUIF 3 >> +#define ARM64_HAS_VIRT_HOST_EXTN 4 >> >> -#define ARM64_NCAPS 4 >> +#define ARM64_NCAPS 5 >> >> #ifndef __ASSEMBLY__ >> >> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c >> index 5ad86ce..e1dcd63 100644 >> --- a/arch/arm64/kernel/cpufeature.c >> +++ b/arch/arm64/kernel/cpufeature.c >> @@ -21,6 +21,7 @@ >> #include >> #include >> #include >> +#include >> >> static bool >> has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry) >> @@ -31,6 +32,11 @@ has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry) >> return (val & entry->register_mask) == entry->register_value; >> } >> >> +static bool runs_at_el2(const struct arm64_cpu_capabilities *entry) >> +{ >> + return is_kernel_in_hyp_mode(); >> +} >> + >> static const struct arm64_cpu_capabilities arm64_features[] = { >> { >> .desc = "GIC system register CPU interface", >> @@ -39,6 +45,11 @@ static const struct arm64_cpu_capabilities arm64_features[] = { >> .register_mask = (0xf << 24), >> .register_value = (1 << 24), >> }, >> + { >> + .desc = "Virtualization Host Extensions", >> + .capability = ARM64_HAS_VIRT_HOST_EXTN, >> + .matches = runs_at_el2, >> + }, >> {}, >> }; >> >> -- >> 2.1.4 >> >> _______________________________________________ >> kvmarm mailing list >> kvmarm@lists.cs.columbia.edu >> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm >> > -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/