mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Wanpeng Li <kernellwp@gmail.com>,
	Haozhong Zhang <haozhong.zhang@intel.com>
Cc: kvm <kvm@vger.kernel.org>, Radim Krcmar <rkrcmar@redhat.com>,
	Yunhong Jiang <yunhong.jiang@intel.com>,
	Wanpeng Li <wanpeng.li@hotmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Jan Kiszka <jan.kiszka@siemens.com>
Subject: Re: [PATCH] KVM: VMX: switch to hrtimer for TSC deadline timer when L2 guest is running
Date: Wed, 6 Jul 2016 08:04:09 +0200	[thread overview]
Message-ID: <1a2c4809-ac93-d0cc-b79a-5ff891d7920c@redhat.com> (raw)
In-Reply-To: <CANRm+Cwfwm3ENPxsh5y+tyvQXir82fruVqJVSfU-gioe2A+N7w@mail.gmail.com>



On 06/07/2016 07:37, Wanpeng Li wrote:
> Cc Jan,
> 2016-07-06 13:10 GMT+08:00 Haozhong Zhang <haozhong.zhang@intel.com>:
>> A different VMCS is loaded when L2 guest is running, so it's incorrect
>> to use the VMX preemption timer for L1 TSC deadline timer. This patch
>> switches to hrtimer for L1 TSC deadline timer when entering L2 guest,
>> and switches back to VMX preemption timer when nested VMEXIT from L2 to
>> L1.
> 
> Nested preemption timer is emulated by hrtimer, so it doesn't
> influence vmcs02, why this is needed?

I agree (and nested APIC timer is emulated by L1).  Because the L1 APIC
timer is set in the preemption timer before vmentry, this should not be
necessary.

Paolo

  reply	other threads:[~2016-07-06  6:04 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-06  5:10 Haozhong Zhang
2016-07-06  5:37 ` Wanpeng Li
2016-07-06  6:04   ` Paolo Bonzini [this message]
2016-07-06  6:05   ` Haozhong Zhang
2016-07-06  7:46     ` Paolo Bonzini
2016-07-06  8:01       ` Haozhong Zhang
2016-07-06  8:09         ` Haozhong Zhang
2016-07-06  8:14           ` Paolo Bonzini
2016-07-06  8:21             ` Haozhong Zhang

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=1a2c4809-ac93-d0cc-b79a-5ff891d7920c@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=haozhong.zhang@intel.com \
    --cc=jan.kiszka@siemens.com \
    --cc=kernellwp@gmail.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rkrcmar@redhat.com \
    --cc=wanpeng.li@hotmail.com \
    --cc=yunhong.jiang@intel.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
all inboxes | Powered by JetHome®