From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Suthikulpanit, Suravee" Subject: [RFC PATCH 6/8] svm: Temporary deactivate AVIC during ExtINT handling Date: Mon, 4 Feb 2019 14:42:22 +0000 Message-ID: <20190204144128.9489-7-suravee.suthikulpanit@amd.com> References: <20190204144128.9489-1-suravee.suthikulpanit@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: "joro@8bytes.org" , "rkrcmar@redhat.com" , "pbonzini@redhat.com" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "hpa@zytor.com" , "jsteckli@amazon.de" , "sironi@amazon.de" , "wawei@amazon.de" , "Suthikulpanit, Suravee" To: "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "x86@kernel.org" Return-path: In-Reply-To: <20190204144128.9489-1-suravee.suthikulpanit@amd.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org AMD AVIC does not support ExtINT. Therefore, AVIC must be temporary deactivated and fall back to using legacy interrupt injection via vINTR and interrupt window. Introduce svm_request_activate/deactivate_avic() helper functions, which handle steps required to activate/deactivate AVIC. Signed-off-by: Suravee Suthikulpanit --- arch/x86/kvm/svm.c | 57 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 54 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a23b1e77acb6..580ab40ba207 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -383,6 +383,8 @@ static u8 rsm_ins_bytes[] =3D "\x0f\xaa"; static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0); static void svm_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa); static void svm_complete_interrupts(struct vcpu_svm *svm); +static void svm_request_activate_avic(struct kvm_vcpu *vcpu); +static bool svm_get_enable_apicv(struct kvm_vcpu *vcpu); =20 static int nested_svm_exit_handled(struct vcpu_svm *svm); static int nested_svm_intercept(struct vcpu_svm *svm); @@ -2085,6 +2087,9 @@ static void avic_set_running(struct kvm_vcpu *vcpu, b= ool is_run) { struct vcpu_svm *svm =3D to_svm(vcpu); =20 + if (!kvm_vcpu_apicv_active(vcpu)) + return; + svm->avic_is_running =3D is_run; if (is_run) avic_vcpu_load(vcpu, vcpu->cpu); @@ -2319,6 +2324,10 @@ static void svm_vcpu_blocking(struct kvm_vcpu *vcpu) =20 static void svm_vcpu_unblocking(struct kvm_vcpu *vcpu) { + if (kvm_check_request(KVM_REQ_APICV_ACTIVATE, vcpu)) + kvm_vcpu_activate_apicv(vcpu); + if (kvm_check_request(KVM_REQ_APICV_DEACTIVATE, vcpu)) + kvm_vcpu_deactivate_apicv(vcpu); avic_set_running(vcpu, true); } =20 @@ -4460,6 +4469,15 @@ static int interrupt_window_interception(struct vcpu= _svm *svm) { kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); svm_clear_vintr(svm); + + /* + * For AVIC, the only reason to end up here is ExtINTs. + * In this case AVIC was temporarily disabled for + * requesting the IRQ window and we have to re-enable it. + */ + if (svm_get_enable_apicv(&svm->vcpu)) + svm_request_activate_avic(&svm->vcpu); + svm->vmcb->control.int_ctl &=3D ~V_IRQ_MASK; mark_dirty(svm->vmcb, VMCB_INTR); ++svm->vcpu.stat.irq_window_exits; @@ -5150,6 +5168,34 @@ static void svm_hwapic_isr_update(struct kvm_vcpu *v= cpu, int max_isr) { } =20 +static bool is_avic_active(struct vcpu_svm *svm) +{ + return (svm_get_enable_apicv(&svm->vcpu) && + svm->vmcb->control.int_ctl & AVIC_ENABLE_MASK); +} + +static void svm_request_activate_avic(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm =3D to_svm(vcpu); + + if (!lapic_in_kernel(vcpu) || is_avic_active(svm)) + return; + + avic_setup_access_page(vcpu, false); + kvm_make_apicv_activate_request(vcpu->kvm); +} + +static void svm_request_deactivate_avic(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm =3D to_svm(vcpu); + + if (!lapic_in_kernel(vcpu) || !is_avic_active(svm)) + return; + + avic_destroy_access_page(vcpu); + kvm_make_apicv_deactivate_request(vcpu->kvm); +} + /* Note: Currently only used by Hyper-V. */ static void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { @@ -5437,9 +5483,6 @@ static void enable_irq_window(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm =3D to_svm(vcpu); =20 - if (kvm_vcpu_apicv_active(vcpu)) - return; - /* * In case GIF=3D0 we can't rely on the CPU to tell us when GIF becomes * 1, because that's a separate STGI/VMRUN intercept. The next time we @@ -5449,6 +5492,14 @@ static void enable_irq_window(struct kvm_vcpu *vcpu) * window under the assumption that the hardware will set the GIF. */ if ((vgif_enabled(svm) || gif_set(svm)) && nested_svm_intr(svm)) { + /* + * IRQ window is not needed when AVIC is enabled, + * unless we have pending ExtINT since it cannot be injected + * via AVIC. In such case, we need to temporarily disable AVIC, + * and fallback to injecting IRQ via V_IRQ. + */ + if (kvm_vcpu_apicv_active(vcpu)) + svm_request_deactivate_avic(&svm->vcpu); svm_set_vintr(svm); svm_inject_irq(svm, 0x0); } --=20 2.17.1