From: Sean Christopherson <[email protected]> KVM unconditionally intercepts WRMSR to MSR_IA32_DEBUGCTLMSR. In the unlikely event that L1 allows L2 to write L1's MSR_IA32_DEBUGCTLMSR, but but saves L2's value on VM-Exit, update vmcs12 during L2's WRMSR so as to eliminate the need to VMREAD the value from vmcs02 on nested VM-Exit.
Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> --- arch/x86/kvm/vmx/nested.c | 4 +--- arch/x86/kvm/vmx/vmx.c | 8 ++++++++ 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 68c031e2cc4d..138f27597c91 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3563,10 +3563,8 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) (vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) | (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE); - if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS) { + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS) kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7); - vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); - } if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER) vmcs12->guest_ia32_efer = vcpu->arch.efer; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ede2ac670f5b..975b2705c5b2 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1845,6 +1845,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) get_vmcs12(vcpu)->guest_sysenter_esp = data; vmcs_writel(GUEST_SYSENTER_ESP, data); break; + case MSR_IA32_DEBUGCTLMSR: + if (is_guest_mode(vcpu) && get_vmcs12(vcpu)->vm_exit_controls & + VM_EXIT_SAVE_DEBUG_CONTROLS) + get_vmcs12(vcpu)->guest_ia32_debugctl = data; + + ret = kvm_set_msr_common(vcpu, msr_info); + break; + case MSR_IA32_BNDCFGS: if (!kvm_mpx_supported() || (!msr_info->host_initiated && -- 1.8.3.1
