From 2ca1a06a5440ae8aa7bb0709336d759395b7bbb8 Mon Sep 17 00:00:00 2001 From: Venkatesh Srinivas Date: Thu, 16 Apr 2020 11:42:54 -0700 Subject: [PATCH] kvm: Handle reads of SandyBridge RAPL PMU MSRs rather than injecting #GP 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@google.com). Signed-off-by: Venkatesh Srinivas Signed-off-by: Jon Cargille Reviewed-by: Jim Mattson Message-Id: <20200416184254.248374-1-jcargill@google.com> Signed-off-by: Paolo Bonzini --- 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 3cc3f673785c..919d3c8f9b65 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: