diff options
Diffstat (limited to 'arch/arm64/kvm/hypercalls.c')
| -rw-r--r-- | arch/arm64/kvm/hypercalls.c | 80 |
1 files changed, 71 insertions, 9 deletions
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index ead21b98b620..30da78f72b3b 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -9,16 +9,65 @@ #include <kvm/arm_hypercalls.h> #include <kvm/arm_psci.h> +static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val) +{ + struct system_time_snapshot systime_snapshot; + u64 cycles = ~0UL; + u32 feature; + + /* + * system time and counter value must captured at the same + * time to keep consistency and precision. + */ + ktime_get_snapshot(&systime_snapshot); + + /* + * This is only valid if the current clocksource is the + * architected counter, as this is the only one the guest + * can see. + */ + if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER) + return; + + /* + * The guest selects one of the two reference counters + * (virtual or physical) with the first argument of the SMCCC + * call. In case the identifier is not supported, error out. + */ + feature = smccc_get_arg1(vcpu); + switch (feature) { + case KVM_PTP_VIRT_COUNTER: + cycles = systime_snapshot.cycles - vcpu_read_sys_reg(vcpu, CNTVOFF_EL2); + break; + case KVM_PTP_PHYS_COUNTER: + cycles = systime_snapshot.cycles; + break; + default: + return; + } + + /* + * This relies on the top bit of val[0] never being set for + * valid values of system time, because that is *really* far + * in the future (about 292 years from 1970, and at that stage + * nobody will give a damn about it). + */ + val[0] = upper_32_bits(systime_snapshot.real); + val[1] = lower_32_bits(systime_snapshot.real); + val[2] = upper_32_bits(cycles); + val[3] = lower_32_bits(cycles); +} + int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { u32 func_id = smccc_get_function(vcpu); - long val = SMCCC_RET_NOT_SUPPORTED; + u64 val[4] = {SMCCC_RET_NOT_SUPPORTED}; u32 feature; gpa_t gpa; switch (func_id) { case ARM_SMCCC_VERSION_FUNC_ID: - val = ARM_SMCCC_VERSION_1_1; + val[0] = ARM_SMCCC_VERSION_1_1; break; case ARM_SMCCC_ARCH_FEATURES_FUNC_ID: feature = smccc_get_arg1(vcpu); @@ -28,10 +77,10 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) case SPECTRE_VULNERABLE: break; case SPECTRE_MITIGATED: - val = SMCCC_RET_SUCCESS; + val[0] = SMCCC_RET_SUCCESS; break; case SPECTRE_UNAFFECTED: - val = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED; + val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED; break; } break; @@ -54,22 +103,35 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) break; fallthrough; case SPECTRE_UNAFFECTED: - val = SMCCC_RET_NOT_REQUIRED; + val[0] = SMCCC_RET_NOT_REQUIRED; break; } break; case ARM_SMCCC_HV_PV_TIME_FEATURES: - val = SMCCC_RET_SUCCESS; + val[0] = SMCCC_RET_SUCCESS; break; } break; case ARM_SMCCC_HV_PV_TIME_FEATURES: - val = kvm_hypercall_pv_features(vcpu); + val[0] = kvm_hypercall_pv_features(vcpu); break; case ARM_SMCCC_HV_PV_TIME_ST: gpa = kvm_init_stolen_time(vcpu); if (gpa != GPA_INVALID) - val = gpa; + val[0] = gpa; + break; + case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID: + val[0] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0; + val[1] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1; + val[2] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2; + val[3] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3; + break; + case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID: + val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES); + val[0] |= BIT(ARM_SMCCC_KVM_FUNC_PTP); + break; + case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID: + kvm_ptp_get_time(vcpu, val); break; case ARM_SMCCC_TRNG_VERSION: case ARM_SMCCC_TRNG_FEATURES: @@ -81,6 +143,6 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) return kvm_psci_call(vcpu); } - smccc_set_retval(vcpu, val, 0, 0, 0); + smccc_set_retval(vcpu, val[0], val[1], val[2], val[3]); return 1; } |