public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Joerg Roedel <joerg.roedel@amd.com>
To: Avi Kivity <avi@qumranet.com>
Cc: kvm-devel <kvm-devel@lists.sourceforge.net>,
	Glauber de Oliveira Costa <gcosta@redhat.com>
Subject: Re: Stop the clock!
Date: Tue, 4 Mar 2008 16:49:10 +0100	[thread overview]
Message-ID: <20080304154910.GI6504@amd.com> (raw)
In-Reply-To: <47CD28DE.7020502@qumranet.com>

On Tue, Mar 04, 2008 at 12:47:58PM +0200, Avi Kivity wrote:
> With paravirt clocksource, reboot and kexec are broken: the clock keeps updating after the reboot, and the new kernel will have a random memory location trampled occasionally.
> 
> So we need to stop the clock on kexec (in the guest) and reboot (in the host).  On the host side, this can be done either in the kernel, or in userspace via new ioctls.
> 
> Joerg, I think you mentioned you were working on a vm-wide reset ioctl()?  If so, that would be the place to stop the clock on reboot.
> 
> Glauber, can you extend the interface to support stopping the clock?  It needs to be done even outside kexec, for example if the the user decides to stop using your clock.

Yes, I am working on that ioctl(), but don't expect a patch this week
because I am busy with an other task temporarily.

Joerg

-- 
           |           AMD Saxony Limited Liability Company & Co. KG
 Operating |         Wilschdorfer Landstr. 101, 01109 Dresden, Germany
 System    |                  Register Court Dresden: HRA 4896
 Research  |              General Partner authorized to represent:
 Center    |             AMD Saxony LLC (Wilmington, Delaware, US)
           | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy


-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/

      parent reply	other threads:[~2008-03-04 15:49 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-04 10:47 Stop the clock! Avi Kivity
2008-03-04 12:41 ` Glauber Costa
2008-03-04 15:49 ` Joerg Roedel [this message]

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=20080304154910.GI6504@amd.com \
    --to=joerg.roedel@amd.com \
    --cc=avi@qumranet.com \
    --cc=gcosta@redhat.com \
    --cc=kvm-devel@lists.sourceforge.net \
    /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