From: Avi Kivity <avi@redhat.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: ya su <suya94335@gmail.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: large amount of NMI_INTERRUPT disgrade winxp VM performance much.
Date: Thu, 11 Aug 2011 09:43:54 +0300 [thread overview]
Message-ID: <4E437A2A.30606@redhat.com> (raw)
In-Reply-To: <625BA99ED14B2D499DC4E29D8138F15062D2B8909F@shsmsx502.ccr.corp.intel.com>
On 08/11/2011 08:41 AM, Tian, Kevin wrote:
> > qemu-system-x86-4454 [004] 549.958172: kvm_exit:
> > reason EXCEPTION_NMI rip 0x8051d5e1
> > qemu-system-x86-4454 [004] 549.958172: kvm_page_fault:
> > address c8f8a000 error_code b
>
> error_code 'b' means the page fault is caused by a write access in kernel
> space, but related page entry has reserved bit set. This is usually used by
> OS for some special tricks, e.g. to handle page swaps. You may check related
> setting in win guest.
>
In this case it was kvm setting the reserved bit.
Looking at your other trace, that server is probably an AMD with the NPT
feature, while your first one is an Intel without the equivalent (EPT).
For this type of workload, you need EPT or NPT.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2011-08-11 6:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-11 3:57 large amount of NMI_INTERRUPT disgrade winxp VM performance much ya su
2011-08-11 5:41 ` Tian, Kevin
2011-08-11 6:41 ` ya su
2011-08-11 6:43 ` Avi Kivity [this message]
2011-08-11 8:59 ` ya su
2011-08-11 9:54 ` Avi Kivity
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=4E437A2A.30606@redhat.com \
--to=avi@redhat.com \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=suya94335@gmail.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).