This validates hypervisor capabilities like VMID width, IPA range for any
hot plug CPU against system finalized values. While here, it factors out
get_vmid_bits() for general use and also defines ID_AA64MMFR0_PARANGE_MASK.

Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <w...@kernel.org>
Cc: Marc Zyngier <m...@kernel.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: James Morse <james.mo...@arm.com>
Cc: Suzuki K Poulose <suzuki.poul...@arm.com>
Cc: linux-arm-ker...@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-ker...@vger.kernel.org

Suggested-by: Suzuki Poulose <suzuki.poul...@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khand...@arm.com>
---
Changes in V2:

- Added is_hyp_mode_available() check per Marc
- Moved verify_kvm_capabilities() into cpufeature.c per Marc
- Added helper get_kvm_ipa_limit() to fetch kvm_ipa_limit per Marc
- Renamed kvm as hyp including the commit message per Marc

Changes in V1: (https://patchwork.kernel.org/patch/11532565/)

 arch/arm64/include/asm/cpufeature.h | 20 +++++++++++++++++
 arch/arm64/include/asm/kvm_mmu.h    |  2 +-
 arch/arm64/include/asm/sysreg.h     |  1 +
 arch/arm64/kernel/cpufeature.c      | 33 +++++++++++++++++++++++++++++
 arch/arm64/kvm/reset.c              | 11 ++++++++--
 5 files changed, 64 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h 
b/arch/arm64/include/asm/cpufeature.h
index afe08251ff95..fbbb4d2216f0 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -745,6 +745,26 @@ 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;
+}
+
+#ifdef CONFIG_KVM_ARM_HOST
+u32 get_kvm_ipa_limit(void);
+#endif
+
 #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/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index c4ac0ac25a00..3510a4668970 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -705,6 +705,7 @@
 #define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1
 #define ID_AA64MMFR0_PARANGE_48                0x5
 #define ID_AA64MMFR0_PARANGE_52                0x6
+#define ID_AA64MMFR0_PARANGE_MASK      0x7
 
 #ifdef CONFIG_ARM64_PA_BITS_52
 #define ID_AA64MMFR0_PARANGE_MAX       ID_AA64MMFR0_PARANGE_52
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9fac745aa7bb..7e5ff452574c 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 & ID_AA64MMFR0_PARANGE_MASK;
+       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..1131b112dda2 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -340,11 +340,17 @@ 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;
 
-       parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 0x7;
+       parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) &
+                                               ID_AA64MMFR0_PARANGE_MASK;
        pa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
 
        /* Clamp the IPA limit to the PA size supported by the kernel */
@@ -406,7 +412,8 @@ int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long 
type)
                phys_shift = KVM_PHYS_SHIFT;
        }
 
-       parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 7;
+       parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) &
+                                               ID_AA64MMFR0_PARANGE_MASK;
        if (parange > ID_AA64MMFR0_PARANGE_MAX)
                parange = ID_AA64MMFR0_PARANGE_MAX;
        vtcr |= parange << VTCR_EL2_PS_SHIFT;
-- 
2.20.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Reply via email to