| Message ID | 1589248647-22925-1-git-send-email-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V3] arm64/cpufeature: Validate hypervisor capabilities during CPU hotplug | expand |
On Tue, 12 May 2020 07:27:27 +0530, Anshuman Khandual wrote: > 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 <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Marc Zyngier <maz@kernel.org> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: James Morse <james.morse@arm.com> > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Cc: linux-arm-kernel@lists.infradead.org > Cc: kvmarm@lists.cs.columbia.edu > Cc: linux-kernel@vger.kernel.org Applied to arm64 (for-next/cpufeature), thanks! [1/1] arm64/cpufeature: Validate hypervisor capabilities during CPU hotplug https://git.kernel.org/arm64/c/c73433fc630c But please note that I made some changes to verify_hyp_capabilities() so that it's (a) static and (b) uses IS_ENABLED to avoid the dummy function definition. I also extended the IS_ENABLED_check so that it doesn't conflict with the KVM kconfig changes from Fuad. Please shout if you think I'm still missing something. Cheers,
On 05/20/2020 11:24 PM, Will Deacon wrote: > On Tue, 12 May 2020 07:27:27 +0530, Anshuman Khandual wrote: >> 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 <catalin.marinas@arm.com> >> Cc: Will Deacon <will@kernel.org> >> Cc: Marc Zyngier <maz@kernel.org> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Cc: James Morse <james.morse@arm.com> >> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: kvmarm@lists.cs.columbia.edu >> Cc: linux-kernel@vger.kernel.org > > Applied to arm64 (for-next/cpufeature), thanks! > > [1/1] arm64/cpufeature: Validate hypervisor capabilities during CPU hotplug > https://git.kernel.org/arm64/c/c73433fc630c > > But please note that I made some changes to verify_hyp_capabilities() so > that it's (a) static and (b) uses IS_ENABLED to avoid the dummy function > definition. I also extended the IS_ENABLED_check so that it doesn't > conflict with the KVM kconfig changes from Fuad. Please shout if you think > I'm still missing something. Normally I would have expected get_kvm_ipa_limit() to be unavailable without CONFIG_KVM_ARM_HOST, causing a build failure. But it does compile correctly. Probably the compiler does not really look for get_kvm_ipa_limit() definition after an early check and bailout on !IS_ENABLED(CONFIG_KVM_ARM_HOST). Nonetheless, changes looks good. Thank you. - Anshuman
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index afe08251ff95..1291ad5a9ccb 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -745,6 +745,24 @@ 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); } /* diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 9fac745aa7bb..30917fe7942a 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2181,6 +2181,36 @@ static void verify_sve_features(void) /* Add checks on other ZCR bits here if necessary */ } +#ifdef CONFIG_KVM_ARM_HOST +void verify_hyp_capabilities(void) +{ + u64 safe_mmfr1, mmfr0, mmfr1; + int parange, ipa_max; + unsigned int safe_vmid_bits, vmid_bits; + + safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + mmfr0 = read_cpuid(ID_AA64MMFR0_EL1); + mmfr1 = read_cpuid(ID_AA64MMFR1_EL1); + + /* Verify VMID bits */ + safe_vmid_bits = get_vmid_bits(safe_mmfr1); + vmid_bits = get_vmid_bits(mmfr1); + if (vmid_bits < safe_vmid_bits) { + pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id()); + cpu_die_early(); + } + + /* Verify IPA range */ + parange = mmfr0 & 0x7; + ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange); + if (ipa_max < get_kvm_ipa_limit()) { + pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id()); + cpu_die_early(); + } +} +#else /* !CONFIG_KVM_ARM_HOST */ +static inline void verify_hyp_capabilities(void) { } +#endif /* CONFIG_KVM_ARM_HOST */ /* * Run through the enabled system capabilities and enable() it on this CPU. @@ -2206,6 +2236,9 @@ static void verify_local_cpu_capabilities(void) if (system_supports_sve()) verify_sve_features(); + + if (is_hyp_mode_available()) + verify_hyp_capabilities(); } void check_local_cpu_capabilities(void) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 30b7ea680f66..841b492ff334 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -340,6 +340,11 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) return ret; } +u32 get_kvm_ipa_limit(void) +{ + return kvm_ipa_limit; +} + void kvm_set_ipa_limit(void) { unsigned int ipa_max, pa_max, va_max, parange;