From 5f3c6a6c50093815eb56c97ba5cbadef36fbd889 Mon Sep 17 00:00:00 2001 From: Haozhong Zhang Date: Mon, 14 Dec 2015 23:13:38 +0800 Subject: KVM: VMX: Fix host initiated access to guest MSR_TSC_AUX [ Upstream commit 81b1b9ca6d5ca5f3ce91c0095402def657cf5db3 ] The current handling of accesses to guest MSR_TSC_AUX returns error if vcpu does not support rdtscp, though those accesses are initiated by host. This can result in the reboot failure of some versions of QEMU. This patch fixes this issue by passing those host initiated accesses for further handling instead. Signed-off-by: Haozhong Zhang Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 21008619878d..048830f2927d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2691,7 +2691,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vcpu->arch.ia32_xss; break; case MSR_TSC_AUX: - if (!to_vmx(vcpu)->rdtscp_enabled) + if (!to_vmx(vcpu)->rdtscp_enabled && !msr_info->host_initiated) return 1; /* Otherwise falls through */ default: @@ -2797,7 +2797,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) clear_atomic_switch_msr(vmx, MSR_IA32_XSS); break; case MSR_TSC_AUX: - if (!vmx->rdtscp_enabled) + if (!vmx->rdtscp_enabled && !msr_info->host_initiated) return 1; /* Check reserved bit, higher 32 bits should be zero */ if ((data >> 32) != 0) -- cgit v1.2.3