From: Wanpeng Li <kernellwp@gmail.com>
To: Sean Christopherson <seanjc@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>, kvm <kvm@vger.kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH 1/2] KVM: LAPIC: write 0 to TMICT should also cancel vmx-preemption timer
Date: Tue, 8 Jun 2021 08:30:27 +0800 [thread overview]
Message-ID: <CANRm+CzMNctK1nWfTf10ch2TDB-6Trh4JSOGqONm4zjnctoP-g@mail.gmail.com> (raw)
In-Reply-To: <YLpIni1VKYYfUE8D@google.com>
On Fri, 4 Jun 2021 at 23:37, Sean Christopherson <seanjc@google.com> wrote:
>
> On Fri, Jun 04, 2021, Wanpeng Li wrote:
> > On Thu, 3 Jun 2021 at 23:20, Sean Christopherson <seanjc@google.com> wrote:
> > >
> > > On Thu, Jun 03, 2021, Wanpeng Li wrote:
> > > > From: Wanpeng Li <wanpengli@tencent.com>
> > > >
> > > > According to the SDM 10.5.4.1:
> > > >
> > > > A write of 0 to the initial-count register effectively stops the local
> > > > APIC timer, in both one-shot and periodic mode.
> > > >
> > > > The lapic timer oneshot/periodic mode which is emulated by vmx-preemption
> > > > timer doesn't stop since vmx->hv_deadline_tsc is still set.
> > >
> > > But the VMX preemption timer is only used for deadline, never for oneshot or
> > > periodic. Am I missing something?
> >
> > Yes, it is upstream.
>
> Huh. I always thought 'tscdeadline' alluded to the timer being in deadline mode
> and never looked closely at the arming code. Thanks!
>
> Maybe name the new helper cancel_apic_timer() to align with start_apic_timer()
> and restart_apic_timer()? With that:
>
> Reviewed-by: Sean Christopherson <seanjc@google.com>
Do it in v2, thanks.
Wanpeng
next prev parent reply other threads:[~2021-06-08 0:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 9:00 [PATCH 1/2] KVM: LAPIC: write 0 to TMICT should also cancel vmx-preemption timer Wanpeng Li
2021-06-03 9:00 ` [PATCH 2/2] KVM: LAPIC: reset TMCCT during vCPU reset Wanpeng Li
2021-06-03 12:27 ` Jim Mattson
2021-06-03 15:34 ` Sean Christopherson
2021-06-08 0:31 ` Wanpeng Li
2021-06-03 15:20 ` [PATCH 1/2] KVM: LAPIC: write 0 to TMICT should also cancel vmx-preemption timer Sean Christopherson
2021-06-04 0:36 ` Wanpeng Li
2021-06-04 15:37 ` Sean Christopherson
2021-06-08 0:30 ` Wanpeng Li [this message]
2021-06-03 23:02 ` David Matlack
2021-06-04 0:32 ` Wanpeng Li
2021-06-04 15:59 ` David Matlack
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=CANRm+CzMNctK1nWfTf10ch2TDB-6Trh4JSOGqONm4zjnctoP-g@mail.gmail.com \
--to=kernellwp@gmail.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.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).