From: Paolo Bonzini <pbonzini@redhat.com>
To: "Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"vkuznets@redhat.com" <vkuznets@redhat.com>,
"rkagan@virtuozzo.com" <rkagan@virtuozzo.com>,
"graf@amazon.com" <graf@amazon.com>,
"jschoenh@amazon.de" <jschoenh@amazon.de>,
"karahmed@amazon.de" <karahmed@amazon.de>,
"rimasluk@amazon.com" <rimasluk@amazon.com>,
"Grimm, Jon" <Jon.Grimm@amd.com>
Subject: Re: [PATCH v4 12/17] svm: Temporary deactivate AVIC during ExtINT handling
Date: Sat, 2 Nov 2019 11:01:04 +0100 [thread overview]
Message-ID: <e57e11f4-ec24-6ad1-22ce-97da1910ed02@redhat.com> (raw)
In-Reply-To: <1572648072-84536-13-git-send-email-suravee.suthikulpanit@amd.com>
On 01/11/19 23:41, Suthikulpanit, Suravee wrote:
> + /*
> + * 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_update_avic(vcpu, false);
This must be pretty heavy-weight on SMP VMs, even if most ExtINT guests
do not need SMP in the guest. One alternative is to enable/disable
APICv when LVT or IOAPIC registers are written with ExtINT mode. Not a
blocker, just an idea to consider.
Paolo
next prev parent reply other threads:[~2019-11-02 10:01 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-01 22:41 [PATCH v4 00/17] kvm: x86: Support AMD SVM AVIC w/ in-kernel irqchip mode Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 01/17] kvm: x86: Modify kvm_x86_ops.get_enable_apicv() to use struct kvm parameter Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 02/17] kvm: lapic: Introduce APICv update helper function Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 03/17] kvm: x86: Introduce APICv deactivate bits Suthikulpanit, Suravee
2019-11-02 9:51 ` Paolo Bonzini
2019-11-01 22:41 ` [PATCH v4 04/17] kvm: x86: Add support for activate/de-activate APICv at runtime Suthikulpanit, Suravee
2019-11-02 9:52 ` Paolo Bonzini
2019-11-04 19:22 ` Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 05/17] kvm: x86: Add APICv activate/deactivate request trace points Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 06/17] kvm: x86: svm: Add support to activate/deactivate posted interrupts Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 07/17] svm: Add support for setup/destroy virutal APIC backing page for AVIC Suthikulpanit, Suravee
2019-11-04 21:53 ` Roman Kagan
2019-11-12 0:05 ` Suravee Suthikulpanit
2019-11-01 22:41 ` [PATCH v4 08/17] kvm: x86: Introduce APICv pre-update hook Suthikulpanit, Suravee
2019-11-04 22:05 ` Roman Kagan
2019-11-12 0:08 ` Suravee Suthikulpanit
2019-11-12 11:12 ` Roman Kagan
2019-11-01 22:41 ` [PATCH v4 09/17] svm: Add support for activate/deactivate AVIC at runtime Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 10/17] kvm: x86: hyperv: Use APICv update request interface Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 11/17] svm: Deactivate AVIC when launching guest with nested SVM support Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 12/17] svm: Temporary deactivate AVIC during ExtINT handling Suthikulpanit, Suravee
2019-11-02 10:01 ` Paolo Bonzini [this message]
2019-11-01 22:41 ` [PATCH v4 13/17] kvm: i8254: Deactivate APICv when using in-kernel PIT re-injection mode Suthikulpanit, Suravee
2019-11-02 9:57 ` Paolo Bonzini
2019-11-04 18:54 ` Suthikulpanit, Suravee
2019-11-04 21:49 ` Paolo Bonzini
2019-11-05 7:05 ` Graf (AWS), Alexander
2019-11-05 8:40 ` Roman Kagan
2019-11-04 23:17 ` Roman Kagan
2019-11-05 22:47 ` Paolo Bonzini
2019-11-11 17:37 ` Suravee Suthikulpanit
2019-11-12 12:22 ` Roman Kagan
2019-11-01 22:41 ` [PATCH v4 14/17] kvm: lapic: Clean up APIC predefined macros Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 15/17] kvm: ioapic: Refactor kvm_ioapic_update_eoi() Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 16/17] kvm: ioapic: Lazy update IOAPIC EOI Suthikulpanit, Suravee
2019-11-01 22:41 ` [PATCH v4 17/17] svm: Allow AVIC with in-kernel irqchip mode Suthikulpanit, Suravee
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