From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4A11E31A79 for ; Thu, 16 Nov 2023 14:29:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A24BA1691; Thu, 16 Nov 2023 06:30:37 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 074733F73F; Thu, 16 Nov 2023 06:29:49 -0800 (PST) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Suzuki K Poulose , James Morse , Zenghui Yu , Ard Biesheuvel , Anshuman Khandual Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: [PATCH v5 04/12] arm64: Add ARM64_HAS_LPA2 CPU capability Date: Thu, 16 Nov 2023 14:29:23 +0000 Message-Id: <20231116142931.1675485-5-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231116142931.1675485-1-ryan.roberts@arm.com> References: <20231116142931.1675485-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Expose FEAT_LPA2 as a capability so that we can take advantage of alternatives patching in the hypervisor. Although FEAT_LPA2 presence is advertised separately for stage1 and stage2, the expectation is that in practice both stages will either support or not support it. Therefore, we combine both into a single capability, allowing us to simplify the implementation. KVM requires support in both stages in order to use LPA2 since the same library is used for hyp stage 1 and guest stage 2 pgtables. Signed-off-by: Ryan Roberts --- arch/arm64/include/asm/cpufeature.h | 5 ++++ arch/arm64/kernel/cpufeature.c | 39 +++++++++++++++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 3 files changed, 45 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index f6d416fe49b0..acf109581ac0 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -819,6 +819,11 @@ static inline bool system_supports_tlb_range(void) return alternative_has_cap_unlikely(ARM64_HAS_TLB_RANGE); } +static inline bool system_supports_lpa2(void) +{ + return cpus_have_final_cap(ARM64_HAS_LPA2); +} + int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt); bool try_emulate_mrs(struct pt_regs *regs, u32 isn); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 0e7d0c2bab36..38dfdaff8176 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1768,6 +1768,39 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, return !meltdown_safe; } +#if defined(CONFIG_ARM64_4K_PAGES) || defined(CONFIG_ARM64_16K_PAGES) +static bool has_lpa2_at_stage1(u64 mmfr0) +{ + unsigned int tgran; + + tgran = cpuid_feature_extract_unsigned_field(mmfr0, + ID_AA64MMFR0_EL1_TGRAN_SHIFT); + return tgran == ID_AA64MMFR0_EL1_TGRAN_LPA2; +} + +static bool has_lpa2_at_stage2(u64 mmfr0) +{ + unsigned int tgran; + + tgran = cpuid_feature_extract_unsigned_field(mmfr0, + ID_AA64MMFR0_EL1_TGRAN_2_SHIFT); + return tgran == ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_LPA2; +} + +static bool has_lpa2(const struct arm64_cpu_capabilities *entry, int scope) +{ + u64 mmfr0; + + mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); + return has_lpa2_at_stage1(mmfr0) && has_lpa2_at_stage2(mmfr0); +} +#else +static bool has_lpa2(const struct arm64_cpu_capabilities *entry, int scope) +{ + return false; +} +#endif + #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 #define KPTI_NG_TEMP_VA (-(1UL << PMD_SHIFT)) @@ -2733,6 +2766,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP) }, + { + .desc = "52-bit Virtual Addressing for KVM (LPA2)", + .capability = ARM64_HAS_LPA2, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_lpa2, + }, {}, }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index b98c38288a9d..919eceb0b3da 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -37,6 +37,7 @@ HAS_GIC_PRIO_MASKING HAS_GIC_PRIO_RELAXED_SYNC HAS_HCX HAS_LDAPR +HAS_LPA2 HAS_LSE_ATOMICS HAS_MOPS HAS_NESTED_VIRT -- 2.25.1