From: Sean Christopherson Date: Fri, 1 Nov 2024 19:14:46 +0000 (-0700) Subject: KVM: nVMX: Use vmcs01's controls shadow to check for IRQ/NMI windows at VM-Enter X-Git-Tag: v6.14-rc1~94^2~5^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c829d2c35650e9e24dc338234bd14e4c7c6231f5;p=thirdparty%2Fkernel%2Flinux.git KVM: nVMX: Use vmcs01's controls shadow to check for IRQ/NMI windows at VM-Enter Use vmcs01's execution controls shadow to check for IRQ/NMI windows after a successful nested VM-Enter, instead of snapshotting the information prior to emulating VM-Enter. It's quite difficult to see that the entire reason controls are snapshot prior nested VM-Enter is to read them from vmcs01 (vmcs02 is loaded if nested VM-Enter is successful). That could be solved with a comment, but explicitly using vmcs01's shadow makes the code self-documenting to a certain extent. No functional change intended (vmcs01's execution controls must not be modified during emulation of nested VM-Enter). Link: https://lore.kernel.org/r/20241101191447.1807602-5-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 3570c30195156..f4064c68dd17e 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3500,7 +3500,6 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx = to_vmx(vcpu); struct vmcs12 *vmcs12 = get_vmcs12(vcpu); enum vm_entry_failure_code entry_failure_code; - bool evaluate_pending_interrupts; union vmx_exit_reason exit_reason = { .basic = EXIT_REASON_INVALID_STATE, .failed_vmentry = 1, @@ -3519,9 +3518,6 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, kvm_service_local_tlb_flush_requests(vcpu); - evaluate_pending_interrupts = exec_controls_get(vmx) & - (CPU_BASED_INTR_WINDOW_EXITING | CPU_BASED_NMI_WINDOW_EXITING); - if (!vmx->nested.nested_run_pending || !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) vmx->nested.pre_vmenter_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); @@ -3604,9 +3600,11 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, * Re-evaluate pending events if L1 had a pending IRQ/NMI/INIT/SIPI * when it executed VMLAUNCH/VMRESUME, as entering non-root mode can * effectively unblock various events, e.g. INIT/SIPI cause VM-Exit - * unconditionally. + * unconditionally. Take care to pull data from vmcs01 as appropriate, + * e.g. when checking for interrupt windows, as vmcs02 is now loaded. */ - if (unlikely(evaluate_pending_interrupts) || + if ((__exec_controls_get(&vmx->vmcs01) & (CPU_BASED_INTR_WINDOW_EXITING | + CPU_BASED_NMI_WINDOW_EXITING)) || kvm_apic_has_pending_init_or_sipi(vcpu) || kvm_apic_has_interrupt(vcpu)) kvm_make_request(KVM_REQ_EVENT, vcpu);