From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: KVM call minutes for June 8
Date: Tue, 08 Jun 2010 11:01:19 -0500
Message-ID: <4C0E694F.8040607@codemonkey.ws>
References: <20100608150500.GA28492@x200.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org
To: Chris Wright <chrisw@redhat.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mail-iw0-f174.google.com ([209.85.214.174]:44284 "EHLO
	mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751657Ab0FHQBZ (ORCPT <rfc822;kvm@vger.kernel.org>);
	Tue, 8 Jun 2010 12:01:25 -0400
Received: by iwn37 with SMTP id 37so4755515iwn.19
        for <kvm@vger.kernel.org>; Tue, 08 Jun 2010 09:01:24 -0700 (PDT)
In-Reply-To: <20100608150500.GA28492@x200.localdomain>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 06/08/2010 10:05 AM, Chris Wright wrote:
> Accelerating counters (aka moving PIT to userspace, keeping HPET in
> userspace)
> - PIT (in-kernel, userspace, or split)
> - userspace PIT, too slow
> - kernel PIT (already seen bugs)
> - split PIT, not realistic w/out a sane interface (see bugs above)
> - exit to userspace is a base cost, add MSR save/restore, add qemu
>    overhead...and exit to userspace is expensive
> - hpet in userspace (at least minimal counter reading)
> - ioapic
>    - less than half is architectural, more than half endds of being
>       interrupt reinjection
>
> Live migration + hotplug
> - start a machine, hotplug device, allocate ram...can't migrate
>    - last_offset and ramblock sections coming from cmdline may not be
>      compatible w/ hotplug
>    - worst case is different ramblock order and data corruption
> - alex has patches to convert ramblocks into queuelist
>    - give name, offset
>    - will clean up and send out today
>
> migration events?
> - QMP (wire protocol) has nice async events
>    - QError reasonable
>    - migration is async command, can complete w/ error or success
> - QMP broken for error
>    - need context for error, default is monitor, but async command
>    - redo qerror_report, propagate error (or always have error context
>      available)
> - monitor and qmp done w/ same dispatch functions
>    - should do monitor in terms of qmp
>      - every qerror replacing monitor printf error
>        - ends up not sharing enough ($foo not found, where $foo is contextual)
> - async command (pass in command completion)
> - may have to do limited (throw away for 0.13 and redo properly for 0.14)
> - anthony has a (not fully working) tree, and will document direction on wiki
>    

http://wiki.qemu.org/Features/QMP2

Includes a pointer to the current tree I'm working out of.

Regards,

Anthony Liguori