From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, will@kernel.org,
catalin.marinas@arm.com, mark.rutland@arm.com
Cc: Mark Brown <broonie@kernel.org>,
James Clark <james.clark@arm.com>, Rob Herring <robh@kernel.org>,
Marc Zyngier <maz@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
linux-perf-users@vger.kernel.org,
Oliver Upton <oliver.upton@linux.dev>,
James Morse <james.morse@arm.com>,
kvmarm@lists.linux.dev
Subject: Re: [PATCH V16 2/8] KVM: arm64: Prevent guest accesses into BRBE system registers/instructions
Date: Tue, 30 Jan 2024 09:10:23 +0530 [thread overview]
Message-ID: <4395415b-dfb1-4dd1-9dfd-181f0549be7c@arm.com> (raw)
In-Reply-To: <95d829b3-d30e-4dcd-a7ca-69d80b9be418@arm.com>
On 1/29/24 17:45, Suzuki K Poulose wrote:
> On 25/01/2024 09:41, Anshuman Khandual wrote:
>> Currently BRBE feature is not supported in a guest environment. This hides
>> BRBE feature availability via masking ID_AA64DFR0_EL1.BRBE field. This also
>> blocks guest accesses into BRBE system registers and instructions as if the
>> underlying hardware never implemented FEAT_BRBE feature.
>>
>> Cc: Marc Zyngier <maz@kernel.org>
>> Cc: Oliver Upton <oliver.upton@linux.dev>
>> Cc: James Morse <james.morse@arm.com>
>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: kvmarm@lists.linux.dev
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> Changes in V16:
>>
>> - Added BRB_INF_SRC_TGT_EL1 macro for corresponding BRB_[INF|SRC|TGT] expansion
>>
>> arch/arm64/kvm/sys_regs.c | 56 +++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 56 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
>> index 30253bd19917..6a06dc2f0c06 100644
>> --- a/arch/arm64/kvm/sys_regs.c
>> +++ b/arch/arm64/kvm/sys_regs.c
>> @@ -1304,6 +1304,11 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r,
>> return 0;
>> }
>> +#define BRB_INF_SRC_TGT_EL1(n) \
>> + { SYS_DESC(SYS_BRBINF##n##_EL1), undef_access }, \
>> + { SYS_DESC(SYS_BRBSRC##n##_EL1), undef_access }, \
>> + { SYS_DESC(SYS_BRBTGT##n##_EL1), undef_access } \
>> +
>> /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
>> #define DBG_BCR_BVR_WCR_WVR_EL1(n) \
>> { SYS_DESC(SYS_DBGBVRn_EL1(n)), \
>> @@ -1707,6 +1712,9 @@ static u64 read_sanitised_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
>> /* Hide SPE from guests */
>> val &= ~ID_AA64DFR0_EL1_PMSVer_MASK;
>> + /* Hide BRBE from guests */
>> + val &= ~ID_AA64DFR0_EL1_BRBE_MASK;
>> +
>> return val;
>> }
>> @@ -2195,6 +2203,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>> { SYS_DESC(SYS_DC_CISW), access_dcsw },
>> { SYS_DESC(SYS_DC_CIGSW), access_dcgsw },
>> { SYS_DESC(SYS_DC_CIGDSW), access_dcgsw },
>> + { SYS_DESC(OP_BRB_IALL), undef_access },
>> + { SYS_DESC(OP_BRB_INJ), undef_access },
>>
>
> heads up: This may conflict with Marc's patches to move the sys instructions to a separate table. But otherwise, looks good to me.
Sure, will rebase this on recent changes.
next prev parent reply other threads:[~2024-01-30 3:40 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-25 9:41 [PATCH V16 0/8] arm64/perf: Enable branch stack sampling Anshuman Khandual
2024-01-25 9:41 ` [PATCH V16 1/8] arm64/sysreg: Add BRBE registers and fields Anshuman Khandual
2024-01-25 14:20 ` Mark Brown
2024-02-21 13:52 ` Mark Rutland
2024-02-21 13:59 ` Mark Brown
2024-02-21 14:05 ` Mark Rutland
2024-02-21 14:07 ` Mark Brown
2024-02-23 5:28 ` Anshuman Khandual
2024-02-23 13:31 ` Mark Brown
2024-02-23 6:36 ` Anshuman Khandual
2024-02-26 4:22 ` [PATCH] arm64/hw_breakpoint: Determine lengths from generic perf breakpoint macros Anshuman Khandual
2024-02-26 4:26 ` Anshuman Khandual
2024-02-26 4:24 ` [PATCH] arm64/sysreg: Add BRBE registers and fields Anshuman Khandual
2024-02-26 13:18 ` Mark Brown
2024-02-27 10:06 ` Mark Rutland
2024-01-25 9:41 ` [PATCH V16 2/8] KVM: arm64: Prevent guest accesses into BRBE system registers/instructions Anshuman Khandual
2024-01-29 12:15 ` Suzuki K Poulose
2024-01-30 3:40 ` Anshuman Khandual [this message]
2024-02-21 14:01 ` Mark Rutland
2024-02-23 7:28 ` Anshuman Khandual
2024-02-27 10:04 ` Mark Rutland
2024-02-27 11:13 ` Anshuman Khandual
2024-02-29 11:45 ` Suzuki K Poulose
2024-02-29 12:50 ` Mark Rutland
2024-02-29 15:43 ` Suzuki K Poulose
2024-03-01 7:46 ` Anshuman Khandual
2024-03-01 12:49 ` Mark Rutland
2024-01-25 9:41 ` [PATCH V16 3/8] drivers: perf: arm_pmuv3: Enable branch stack sampling framework Anshuman Khandual
2024-01-25 13:44 ` Suzuki K Poulose
2024-01-29 4:35 ` Anshuman Khandual
2024-02-21 17:25 ` Mark Rutland
2024-03-01 5:37 ` Anshuman Khandual
2024-03-01 13:52 ` Mark Rutland
2024-01-25 9:41 ` [PATCH V16 4/8] drivers: perf: arm_pmuv3: Enable branch stack sampling via FEAT_BRBE Anshuman Khandual
2024-02-21 18:23 ` Mark Rutland
2024-02-28 8:11 ` Anshuman Khandual
2024-02-28 11:52 ` Mark Rutland
2024-02-29 8:55 ` Anshuman Khandual
2024-01-25 9:41 ` [PATCH V16 5/8] KVM: arm64: nvhe: Disable branch generation in nVHE guests Anshuman Khandual
2024-01-29 12:20 ` Suzuki K Poulose
2024-01-30 3:41 ` Anshuman Khandual
2024-02-29 18:40 ` Marc Zyngier
2024-03-01 2:20 ` Anshuman Khandual
2024-01-25 9:41 ` [PATCH V16 6/8] perf: test: Speed up running brstack test on an Arm model Anshuman Khandual
2024-01-25 9:41 ` [PATCH V16 7/8] perf: test: Remove empty lines from branch filter test output Anshuman Khandual
2024-01-25 9:41 ` [PATCH V16 8/8] perf: test: Extend branch stack sampling test for Arm64 BRBE Anshuman Khandual
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