public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
	KVM list <kvm@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/6] KVM MMU: optimize for writing cr4
Date: Mon, 12 Apr 2010 18:42:48 +0800	[thread overview]
Message-ID: <4BC2F928.2060407@cn.fujitsu.com> (raw)
In-Reply-To: <4BC2DB27.7060005@redhat.com>

Hi Avi,

Thanks for your comments.

Avi Kivity wrote:

> Later we have:
> 
>>         kvm_x86_ops->set_cr4(vcpu, cr4);
>>         vcpu->arch.cr4 = cr4;
>>         vcpu->arch.mmu.base_role.cr4_pge = (cr4 & X86_CR4_PGE) &&
>> !tdp_enabled;
> 
> All of which depend on cr4.

Oh, destroy_kvm_mmu() is not really destroyed cr3 and we can reload it later
form shadow page cache, so, maybe this patch is unnecessary.

But, i have a another question here, why we need encode 'cr4 & X86_CR4_PGE' into
base_role.cr4_gpe? Why we need allocation different shadow page for global page
and no-global page?

As i know, global page is not static in TLB, and x86 cpu also may flush them form TLB,
maybe we no need treat global page specially... Am i miss something? :-(

Xiao


  reply	other threads:[~2010-04-12 10:45 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-12  7:59 [PATCH 1/6] KVM MMU: remove unused struct Xiao Guangrong
2010-04-12  8:01 ` [PATCH 2/6] KVM MMU: fix kvm_mmu_zap_page() and its calling path Xiao Guangrong
2010-04-12  8:24   ` Avi Kivity
2010-04-12  8:53     ` Xiao Guangrong
2010-04-12  9:08       ` Avi Kivity
2010-04-12  9:22         ` Xiao Guangrong
2010-04-12 10:25           ` Avi Kivity
2010-04-12 12:22             ` Xiao Guangrong
2010-04-12 12:49               ` Avi Kivity
2010-04-12 17:10   ` Marcelo Tosatti
2010-04-13  1:34     ` Xiao Guangrong
2010-04-13 14:59       ` Marcelo Tosatti
2010-04-14  2:14         ` Xiao Guangrong
2010-04-14 16:31           ` Marcelo Tosatti
2010-04-12  8:02 ` [PATCH 3/6] KVM MMU: optimize/cleanup for marking parent unsync Xiao Guangrong
2010-04-12  8:32   ` Avi Kivity
2010-04-12  8:55     ` Xiao Guangrong
2010-04-12 17:12   ` Marcelo Tosatti
2010-04-13  1:53     ` Xiao Guangrong
2010-04-13 11:58       ` Avi Kivity
2010-04-13 15:01       ` Marcelo Tosatti
2010-04-14  3:23         ` Xiao Guangrong
2010-04-14  3:58           ` Xiao Guangrong
2010-04-14 16:35           ` Marcelo Tosatti
2010-04-12  8:03 ` [PATCH 4/6] KVM MMU: optimize for writing cr4 Xiao Guangrong
2010-04-12  8:34   ` Avi Kivity
2010-04-12 10:42     ` Xiao Guangrong [this message]
2010-04-12 11:22       ` Avi Kivity
2010-04-13  3:07         ` Xiao Guangrong
2010-04-13  6:42           ` Avi Kivity
2010-04-12  8:05 ` [PATCH 5/6] KVM MMU: reduce kvm_mmu_page size Xiao Guangrong
2010-04-12  8:36   ` Avi Kivity
2010-04-12 11:11     ` Xiao Guangrong
2010-04-12  8:06 ` [PATCH 6/6] KVM MMU: optimize synchronization shadow pages Xiao Guangrong
2010-04-12  8:43   ` Avi Kivity
2010-04-12 11:14     ` Xiao Guangrong

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=4BC2F928.2060407@cn.fujitsu.com \
    --to=xiaoguangrong@cn.fujitsu.com \
    --cc=avi@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mtosatti@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