From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bandan Das Subject: Re: [PATCH v2 2/3] KVM: nVMX: Ack and write vector info to intr_info if L1 asks us to Date: Fri, 11 Apr 2014 15:17:47 -0400 Message-ID: References: <1396299625-8285-1-git-send-email-bsd@redhat.com> <1396299625-8285-3-git-send-email-bsd@redhat.com> <20140411183332.GA13157@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain Cc: kvm@vger.kernel.org, Paolo Bonzini , Gleb Natapov , Jan Kiszka To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4533 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750880AbaDKTRv (ORCPT ); Fri, 11 Apr 2014 15:17:51 -0400 In-Reply-To: <20140411183332.GA13157@amt.cnet> (Marcelo Tosatti's message of "Fri, 11 Apr 2014 15:33:32 -0300") Sender: kvm-owner@vger.kernel.org List-ID: Marcelo Tosatti writes: > On Mon, Mar 31, 2014 at 05:00:24PM -0400, Bandan Das wrote: >> This feature emulates the "Acknowledge interrupt on exit" behavior. >> We can safely emulate it for L1 to run L2 even if L0 itself has it >> disabled (to run L1). >> >> Signed-off-by: Bandan Das >> --- >> arch/x86/kvm/irq.c | 1 + >> arch/x86/kvm/vmx.c | 19 +++++++++++++++++++ >> 2 files changed, 20 insertions(+) >> >> diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c >> index 484bc87..bd0da43 100644 >> --- a/arch/x86/kvm/irq.c >> +++ b/arch/x86/kvm/irq.c >> @@ -113,6 +113,7 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v) >> >> return kvm_get_apic_interrupt(v); /* APIC */ >> } >> +EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); >> >> void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) >> { >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 3e7f60c..bdc8f2d 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -4489,6 +4489,18 @@ static bool nested_exit_on_intr(struct kvm_vcpu *vcpu) >> PIN_BASED_EXT_INTR_MASK; >> } >> >> +/* >> + * In nested virtualization, check if L1 has enabled >> + * interrupt acknowledgement that writes the interrupt vector >> + * info on vmexit >> + * >> + */ >> +static bool nested_exit_intr_ack_set(struct kvm_vcpu *vcpu) >> +{ >> + return get_vmcs12(vcpu)->vm_exit_controls & >> + VM_EXIT_ACK_INTR_ON_EXIT; >> +} >> + >> static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu) >> { >> return get_vmcs12(vcpu)->pin_based_vm_exec_control & >> @@ -8442,6 +8454,13 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, >> prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info, >> exit_qualification); >> >> + if ((exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT) >> + && nested_exit_intr_ack_set(vcpu)) { >> + int irq = kvm_cpu_get_interrupt(vcpu); > > Can irq be -1 ? If it is, I think that's a bug because if we exited for this reason with INTR_ACK set, the hypervisor expects a valid vector number to be available. What about adding a BUG_ON ? >> + vmcs12->vm_exit_intr_info = irq | >> + INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR; >> + } >> + >> trace_kvm_nested_vmexit_inject(vmcs12->vm_exit_reason, >> vmcs12->exit_qualification, >> vmcs12->idt_vectoring_info_field, >> -- >> 1.8.3.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html