From a0d4f8034446df402a879dac04cab61f71c4fafc Mon Sep 17 00:00:00 2001 From: Krish Sadhukhan Date: Tue, 4 Dec 2018 19:00:13 -0500 Subject: [PATCH] KVM nVMX: MSRs should not be stored if VM-entry fails during or after loading guest state According to section "VM-entry Failures During or After Loading Guest State" in Intel SDM vol 3C, "No MSRs are saved into the VM-exit MSR-store area." when bit 31 of the exit reason is set. Reported-by: Krish Sadhukhan Suggested-by: Jim Mattson Signed-off-by: Krish Sadhukhan Reviewed-by: Darren Kenny Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index bb3a7030eb39..b347d975589d 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3504,6 +3504,18 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, * L2 to IDT_VECTORING_INFO_FIELD. */ vmcs12_save_pending_event(vcpu, vmcs12); + + /* + * According to spec, there's no need to store the guest's + * MSRs if the exit is due to a VM-entry failure that occurs + * during or after loading the guest state. Since this exit + * does not fall in that category, we need to save the MSRs. + */ + if (nested_vmx_store_msr(vcpu, + vmcs12->vm_exit_msr_store_addr, + vmcs12->vm_exit_msr_store_count)) + nested_vmx_abort(vcpu, + VMX_ABORT_SAVE_GUEST_MSR_FAIL); } /* @@ -3835,10 +3847,6 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, * immutable. */ nested_flush_cached_shadow_vmcs12(vcpu, vmcs12); - - if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr, - vmcs12->vm_exit_msr_store_count)) - nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL); } else { /* * The only expected VM-instruction error is "VM entry with -- 2.39.5