From c73433fc630cda102f6527d4e5dfd289a9baec08 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 12 May 2020 07:27:27 +0530 Subject: arm64/cpufeature: Validate hypervisor capabilities during CPU hotplug This validates hypervisor capabilities like VMID width, IPA range for any hot plug CPU against system finalized values. KVM's view of the IPA space is used while allowing a given CPU to come up. While here, it factors out get_vmid_bits() for general use. Cc: Catalin Marinas Cc: Will Deacon Cc: Marc Zyngier Cc: Mark Rutland Cc: James Morse Cc: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org Suggested-by: Suzuki Poulose Signed-off-by: Anshuman Khandual Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/1589248647-22925-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/cpufeature.h | 18 ++++++++++++++++++ arch/arm64/include/asm/kvm_mmu.h | 2 +- 2 files changed, 19 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index f5c4672e498b..928814d35669 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -752,6 +752,24 @@ static inline bool cpu_has_hw_af(void) extern bool cpu_has_amu_feat(int cpu); #endif +static inline unsigned int get_vmid_bits(u64 mmfr1) +{ + int vmid_bits; + + vmid_bits = cpuid_feature_extract_unsigned_field(mmfr1, + ID_AA64MMFR1_VMIDBITS_SHIFT); + if (vmid_bits == ID_AA64MMFR1_VMIDBITS_16) + return 16; + + /* + * Return the default here even if any reserved + * value is fetched from the system register. + */ + return 8; +} + +u32 get_kvm_ipa_limit(void); + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 30b0e8d6b895..a7137e144b97 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -416,7 +416,7 @@ static inline unsigned int kvm_get_vmid_bits(void) { int reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); - return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8; + return get_vmid_bits(reg); } /* -- cgit v1.2.3