From: "Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>
To: Paolo Bonzini <pbonzini@redhat.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 13/17] kvm: i8254: Deactivate APICv when using in-kernel PIT re-injection mode.
Date: Mon, 4 Nov 2019 18:54:57 +0000 [thread overview]
Message-ID: <b4e61499-7247-d39e-cd46-c53388ba347a@amd.com> (raw)
In-Reply-To: <70fb2b49-2198-bde4-a38b-f37bc8bc9847@redhat.com>
Paolo,
Thanks for quick response.
On 11/2/19 4:57 AM, Paolo Bonzini wrote:
> On 01/11/19 23:41, Suthikulpanit, Suravee wrote:
>> + /*
>> + * AMD SVM AVIC accelerates EOI write and does not trap.
>> + * This cause in-kernel PIT re-inject mode to fail
>> + * since it checks ps->irq_ack before kvm_set_irq()
>> + * and relies on the ack notifier to timely queue
>> + * the pt->worker work iterm and reinject the missed tick.
>> + * So, deactivate APICv when PIT is in reinject mode.
>> + */
>> if (reinject) {
>> + kvm_request_apicv_update(kvm, false, APICV_DEACT_BIT_PIT_REINJ);
>> /* The initial state is preserved while ps->reinject == 0. */
>> kvm_pit_reset_reinject(pit);
>> kvm_register_irq_ack_notifier(kvm, &ps->irq_ack_notifier);
>> kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
>> } else {
>> + kvm_request_apicv_update(kvm, true, APICV_DEACT_BIT_PIT_REINJ);
>> kvm_unregister_irq_ack_notifier(kvm, &ps->irq_ack_notifier);
>> kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
>
> This is not too nice for Intel which does support (through the EOI exit
> mask) APICv even if PIT reinjection active.
I see you point.
> We can work around it by adding a global mask of inhibit reasons that
> apply to the vendor, and initializing it as soon as possible in vmx.c/svm.c.
>
> Then kvm_request_apicv_update can ignore reasons that the vendor doesn't
> care about.
>
> Paolo
>
What about we enhance the pre_update_apivc_exec_ctrl() to also return
success/fail. In here, the vendor specific code can decide to update
APICv state or not.
Thanks,
Suravee
next prev parent reply other threads:[~2019-11-04 18:55 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
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b4e61499-7247-d39e-cd46-c53388ba347a@amd.com \
--to=suravee.suthikulpanit@amd.com \
--cc=Jon.Grimm@amd.com \
--cc=graf@amazon.com \
--cc=joro@8bytes.org \
--cc=jschoenh@amazon.de \
--cc=karahmed@amazon.de \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=rimasluk@amazon.com \
--cc=rkagan@virtuozzo.com \
--cc=rkrcmar@redhat.com \
--cc=vkuznets@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).