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author | Paolo Bonzini <pbonzini@redhat.com> | 2023-04-06 20:34:19 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-04-06 20:34:19 +0300 |
commit | 0bf9601f8ef0703523018e975d6c1f3fdfcff4b9 (patch) | |
tree | 85a77bbe60fd8ce78315d06c0b6fb37dab9cc484 | |
parent | fb5015bc8b733323b58f015b88e4f316010ec856 (diff) | |
parent | e81625218bf7986ba1351a98c43d346b15601d26 (diff) | |
download | linux-0bf9601f8ef0703523018e975d6c1f3fdfcff4b9.tar.xz |
Merge tag 'kvmarm-fixes-6.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 6.3, part #3
- Ensure the guest PMU context is restored before the first KVM_RUN,
fixing an issue where EL0 event counting is broken after vCPU
save/restore
- Actually initialize ID_AA64PFR0_EL1.{CSV2,CSV3} based on the
sanitized, system-wide values for protected VMs
-rw-r--r-- | arch/arm64/kvm/arm.c | 26 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/fixed_config.h | 5 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/nvhe/sys_regs.c | 7 | ||||
-rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 1 | ||||
-rw-r--r-- | arch/arm64/kvm/sys_regs.c | 1 |
5 files changed, 30 insertions, 10 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3f6a5efdbcf0..4b2e16e696a8 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1890,9 +1890,33 @@ static int __init do_pkvm_init(u32 hyp_va_bits) return ret; } +static u64 get_hyp_id_aa64pfr0_el1(void) +{ + /* + * Track whether the system isn't affected by spectre/meltdown in the + * hypervisor's view of id_aa64pfr0_el1, used for protected VMs. + * Although this is per-CPU, we make it global for simplicity, e.g., not + * to have to worry about vcpu migration. + * + * Unlike for non-protected VMs, userspace cannot override this for + * protected VMs. + */ + u64 val = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + + val &= ~(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) | + ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3)); + + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), + arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), + arm64_get_meltdown_state() == SPECTRE_UNAFFECTED); + + return val; +} + static void kvm_hyp_init_symbols(void) { - kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = get_hyp_id_aa64pfr0_el1(); kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1); kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1); diff --git a/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h b/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h index 07edfc7524c9..37440e1dda93 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h +++ b/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h @@ -33,11 +33,14 @@ * Allow for protected VMs: * - Floating-point and Advanced SIMD * - Data Independent Timing + * - Spectre/Meltdown Mitigation */ #define PVM_ID_AA64PFR0_ALLOW (\ ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_FP) | \ ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AdvSIMD) | \ - ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_DIT) \ + ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_DIT) | \ + ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) | \ + ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3) \ ) /* diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c index 08d2b004f4b7..edd969a1f36b 100644 --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -85,19 +85,12 @@ static u64 get_restricted_features_unsigned(u64 sys_reg_val, static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu) { - const struct kvm *kvm = (const struct kvm *)kern_hyp_va(vcpu->kvm); u64 set_mask = 0; u64 allow_mask = PVM_ID_AA64PFR0_ALLOW; set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val, PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); - /* Spectre and Meltdown mitigation in KVM */ - set_mask |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), - (u64)kvm->arch.pfr0_csv2); - set_mask |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), - (u64)kvm->arch.pfr0_csv3); - return (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask; } diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index c243b10f3e15..5eca0cdd961d 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -558,6 +558,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) for_each_set_bit(i, &mask, 32) kvm_pmu_set_pmc_value(kvm_vcpu_idx_to_pmc(vcpu, i), 0, true); } + kvm_vcpu_pmu_restore_guest(vcpu); } static bool kvm_pmu_counter_is_enabled(struct kvm_pmc *pmc) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1b2c161120be..34688918c811 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -794,7 +794,6 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, if (!kvm_supports_32bit_el0()) val |= ARMV8_PMU_PMCR_LC; kvm_pmu_handle_pmcr(vcpu, val); - kvm_vcpu_pmu_restore_guest(vcpu); } else { /* PMCR.P & PMCR.C are RAZ */ val = __vcpu_sys_reg(vcpu, PMCR_EL0) |