From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v3 1/3] KVM: nVMX: Rework interception of IRQs and NMIs Date: Fri, 07 Mar 2014 17:46:54 +0100 Message-ID: <5319F7FE.50106@redhat.com> References: <5319E975.1030400@redhat.com> <5319F3E2.3020205@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm To: Jan Kiszka , Gleb Natapov , Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4834 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753973AbaCGQrD (ORCPT ); Fri, 7 Mar 2014 11:47:03 -0500 In-Reply-To: <5319F3E2.3020205@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 07/03/2014 17:29, Jan Kiszka ha scritto: > On 2014-03-07 16:44, Paolo Bonzini wrote: >> With this patch do we still need >> >> if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >> /* >> * We get here if vmx_interrupt_allowed() said we can't >> * inject to L1 now because L2 must run. The caller will have >> * to make L2 exit right after entry, so we can inject to L1 >> * more promptly. >> */ >> return -EBUSY; >> >> in enable_irq_window? If not, enable_nmi_window and enable_irq_window >> can both return void. > > I don't see right now why this should have changed. We still cannot > interrupt vmlaunch/vmresume. But then shouldn't the ame be true for enable_nmi_window? It doesn't check is_guest_mode(vcpu) && nested_exit_on_nmi(vcpu). Since check_nested_events has already returned -EBUSY, perhaps the following: diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index fda1028..df320e9 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4522,15 +4522,6 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) { u32 cpu_based_vm_exec_control; - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) - /* - * We get here if vmx_interrupt_allowed() said we can't - * inject to L1 now because L2 must run. The caller will have - * to make L2 exit right after entry, so we can inject to L1 - * more promptly. - */ - return -EBUSY; - cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a03d611..83c2df5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5970,13 +5970,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) inject_pending_event(vcpu); - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) - req_immediate_exit |= - kvm_x86_ops->check_nested_events(vcpu, - req_int_win) != 0; + if (is_guest_mode(vcpu) && + kvm_x86_ops->check_nested_events && + kvm_x86_ops->check_nested_events(vcpu, req_int_win) != 0) + req_immediate_exit = true; /* enable NMI/IRQ window open exits if needed */ - if (vcpu->arch.nmi_pending) + else if (vcpu->arch.nmi_pending) req_immediate_exit |= kvm_x86_ops->enable_nmi_window(vcpu) != 0; else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win)