From: Venkatesh Srinivas <venkateshs@xxxxxxxxxx> Linux 3.14 unconditionally reads the RAPL PMU MSRs on boot, without handling General Protection Faults on reading those MSRs. Rather than injecting a #GP, which prevents boot, handle the MSRs by returning 0 for their data. Zero was checked to be safe by code review of the RAPL PMU driver and in discussion with the original driver author (eranian@xxxxxxxxxx). Signed-off-by: Venkatesh Srinivas <venkateshs@xxxxxxxxxx> Signed-off-by: Jon Cargille <jcargill@xxxxxxxxxx> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3cc3f673785c8..4f9b7dd687e3c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3060,6 +3060,17 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_PERF_CTL: case MSR_AMD64_DC_CFG: case MSR_F15H_EX_CFG: + /* + * Intel Sandy Bridge CPUs must support the RAPL (running average power + * limit) MSRs. Just return 0, as we do not want to expose the host + * data here. Do not conditionalize this on CPUID, as KVM does not do + * so for existing CPU-specific MSRs. + */ + case MSR_RAPL_POWER_UNIT: + case MSR_PP0_ENERGY_STATUS: /* Power plane 0 (core) */ + case MSR_PP1_ENERGY_STATUS: /* Power plane 1 (graphics uncore) */ + case MSR_PKG_ENERGY_STATUS: /* Total package */ + case MSR_DRAM_ENERGY_STATUS: /* DRAM controller */ msr_info->data = 0; break; case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5: -- 2.26.0.110.g2183baf09c-goog
