From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759262AbXIYEF1 (ORCPT ); Tue, 25 Sep 2007 00:05:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751298AbXIYEFU (ORCPT ); Tue, 25 Sep 2007 00:05:20 -0400 Received: from emailhub.stusta.mhn.de ([141.84.69.5]:32842 "EHLO mailhub.stusta.mhn.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751183AbXIYEFT (ORCPT ); Tue, 25 Sep 2007 00:05:19 -0400 Date: Tue, 25 Sep 2007 06:05:37 +0200 From: Adrian Bunk To: Rusty Russell Cc: lkml - Kernel Mailing List , virtualization , Andi Kleen Subject: Re: [PATCH 1/3] Virtualization config cleanup: Select CONFIG_PARAVIRT when required Message-ID: <20070925040537.GL6800@stusta.de> References: <1190692688.27805.276.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1190692688.27805.276.camel@localhost.localdomain> User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 25, 2007 at 01:58:08PM +1000, Rusty Russell wrote: > (Unless there are complaints, I'll push this as part of the lguest > patches for 2.6.24, since there are lguest config changes there too). > > Andi points out that PARAVIRT is an option best selected when needed. > > We introduce PARAVIRT_GUEST for the menu itself, and select PARAVIRT > if the user turns on anything which needs it. > > Signed-off-by: Rusty Russell > --- > arch/i386/Kconfig | 33 ++++++++++++++++++++------------- > arch/i386/xen/Kconfig | 1 + > 2 files changed, 21 insertions(+), 13 deletions(-) > > =================================================================== > --- a/arch/i386/Kconfig > +++ b/arch/i386/Kconfig > @@ -214,24 +214,30 @@ config X86_ES7000 > > endchoice > > -menuconfig PARAVIRT > +config PARAVIRT > + bool > + depends on !(X86_VISWS || X86_VOYAGER) > + help > + This changes the kernel so it can modify itself when it is run > + under a hypervisor, potentially improving performance significantly > + over full virtualization. However, when run without a hypervisor > + the kernel is theoretically slower and slightly larger. > + > +menuconfig PARAVIRT_GUEST > - bool "Paravirtualized guest support (EXPERIMENTAL)" > - depends on EXPERIMENTAL > + bool "Paravirtualized guest support" > - depends on !(X86_VISWS || X86_VOYAGER) > - help > - Paravirtualization is a way of running multiple instances of > - Linux on the same machine, under a hypervisor. This option > - changes the kernel so it can modify itself when it is run > - under a hypervisor, improving performance significantly. > - However, when run without a hypervisor the kernel is > - theoretically slower. If in doubt, say N. > - > -if PARAVIRT > + help > + Say Y here to get to see options related to running Linux under > + various hypervisors. This option alone does not add any kernel code. > + > + If you say N, all options in this submenu will be skipped and disabled. > + > +if PARAVIRT_GUEST > > source "arch/i386/xen/Kconfig" > > config VMI > bool "VMI Guest support" > + select PARAVIRT depends on !(X86_VISWS || X86_VOYAGER) > help > VMI provides a paravirtualized interface to the VMware ESX server > (it could be used by other hypervisors in theory too, but is not > @@ -239,6 +246,7 @@ config VMI > > config LGUEST_GUEST > bool "Lguest guest support" > + select PARAVIRT > depends on !X86_PAE depends on !(X86_VISWS || X86_VOYAGER) > help > Lguest is a tiny in-kernel hypervisor. Selecting this will > =================================================================== > --- a/arch/i386/xen/Kconfig > +++ b/arch/i386/xen/Kconfig > @@ -4,6 +4,7 @@ > > config XEN > bool "Xen guest support" > + select PARAVIRT > depends on X86_CMPXCHG && X86_TSC && !NEED_MULTIPLE_NODES depends on !(X86_VISWS || X86_VOYAGER) > help > This is the Linux Xen port. Enabling this will allow the cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed