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From: Dan Hecht <dhecht@vmware.com>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>, Andrew Morton <akpm@osdl.org>,
	virtualization@lists.osdl.org, xen-devel@lists.xensource.com,
	Chris Wright <chrisw@sous-sol.org>,
	Ian Pratt <ian.pratt@xensource.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options.
Date: Tue, 13 Feb 2007 14:53:38 -0800	[thread overview]
Message-ID: <45D24172.9020800@vmware.com> (raw)
In-Reply-To: <20070213221830.542511707@goop.org>

On 02/13/2007 02:17 PM, Jeremy Fitzhardinge wrote:
> The XEN config option enables the Xen paravirt_ops interface, which is
> installed when the kernel finds itself running under Xen. (By some
> as-yet fully defined mechanism, implemented in a future patch.)
> 
> Xen is no longer a sub-architecture, so the X86_XEN subarch config
> option has gone.
> 
> The disabled config options are:
> - PREEMPT: Xen doesn't support it
> - HZ: set to 100Hz for now, to cut down on VCPU context switch rate.
>   This will be adapted to use tickless later.
> - kexec: not yet supported
> 

I assume you plan to eventually get all this stuff working but just want 
to prevent configurations that the Xen paravirt-ops isn't ready for at 
the moment?

Instead can you do it this way:

config XEN
     depends on PARAVIRT && !PREEMPT && HZ_100 && !DOUBLEFAULT && !KEXEC


thanks,
Dan


> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
> Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
> Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
> 
> ---
>  arch/i386/Kconfig       |    7 +++++--
>  arch/i386/Kconfig.debug |    1 +
>  arch/i386/xen/Kconfig   |   10 ++++++++++
>  kernel/Kconfig.hz       |    4 ++--
>  kernel/Kconfig.preempt  |    1 +
>  5 files changed, 19 insertions(+), 4 deletions(-)
> 
> ===================================================================
> --- a/arch/i386/Kconfig
> +++ b/arch/i386/Kconfig
> @@ -192,6 +192,8 @@ config PARAVIRT
>  	  under a hypervisor, improving performance significantly.
>  	  However, when run without a hypervisor the kernel is
>  	  theoretically slower.  If in doubt, say N.
> +
> +source "arch/i386/xen/Kconfig"
>  
>  config ACPI_SRAT
>  	bool
> @@ -298,12 +300,12 @@ config X86_UP_IOAPIC
>  
>  config X86_LOCAL_APIC
>  	bool
> -	depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
> +	depends on X86_UP_APIC || (((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH)
>  	default y
>  
>  config X86_IO_APIC
>  	bool
> -	depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
> +	depends on X86_UP_IOAPIC || ((SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH)
>  	default y
>  
>  config X86_VISWS_APIC
> @@ -743,6 +745,7 @@ source kernel/Kconfig.hz
>  
>  config KEXEC
>  	bool "kexec system call"
> +	depends on !XEN
>  	help
>  	  kexec is a system call that implements the ability to shutdown your
>  	  current kernel, and to start another kernel.  It is like a reboot
> ===================================================================
> --- a/arch/i386/Kconfig.debug
> +++ b/arch/i386/Kconfig.debug
> @@ -79,6 +79,7 @@ config DOUBLEFAULT
>  config DOUBLEFAULT
>  	default y
>  	bool "Enable doublefault exception handler" if EMBEDDED
> +	depends on !XEN
>  	help
>            This option allows trapping of rare doublefault exceptions that
>            would otherwise cause a system to silently reboot. Disabling this
> ===================================================================
> --- /dev/null
> +++ b/arch/i386/xen/Kconfig
> @@ -0,0 +1,10 @@
> +#
> +# This Kconfig describes xen options
> +#
> +
> +config XEN
> +	bool "Enable support for Xen hypervisor"
> +	depends PARAVIRT
> +	default y
> +	help
> +	  This is the Linux Xen port.
> ===================================================================
> --- a/kernel/Kconfig.hz
> +++ b/kernel/Kconfig.hz
> @@ -3,7 +3,7 @@
>  #
>  
>  choice
> -	prompt "Timer frequency"
> +	prompt "Timer frequency" if !XEN
>  	default HZ_250
>  	help
>  	 Allows the configuration of the timer frequency. It is customary
> @@ -49,7 +49,7 @@ endchoice
>  
>  config HZ
>  	int
> -	default 100 if HZ_100
> +	default 100 if HZ_100 || XEN
>  	default 250 if HZ_250
>  	default 300 if HZ_300
>  	default 1000 if HZ_1000
> ===================================================================
> --- a/kernel/Kconfig.preempt
> +++ b/kernel/Kconfig.preempt
> @@ -35,6 +35,7 @@ config PREEMPT_VOLUNTARY
>  
>  config PREEMPT
>  	bool "Preemptible Kernel (Low-Latency Desktop)"
> +	depends on !XEN
>  	help
>  	  This option reduces the latency of the kernel by making
>  	  all kernel code (that is not executing in a critical section)
> 


  parent reply	other threads:[~2007-02-13 23:26 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20070213221729.772002682@goop.org>
     [not found] ` <20070213221829.929261125@goop.org>
2007-02-13 22:39   ` [patch 06/21] Xen-paravirt: remove ctor for pgd cache Zachary Amsden
     [not found] ` <20070213221830.466651996@goop.org>
2007-02-13 22:45   ` [patch 13/21] Xen-paravirt: Add nosegneg capability to the vsyscall page notes Zachary Amsden
2007-02-13 22:49     ` Jeremy Fitzhardinge
2007-02-13 22:54       ` Zachary Amsden
2007-02-13 23:13         ` Jeremy Fitzhardinge
2007-02-14  5:38     ` [Xen-devel] " Rusty Russell
     [not found] ` <20070213221830.542511707@goop.org>
2007-02-13 22:53   ` Dan Hecht [this message]
2007-02-13 23:29     ` [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options Jeremy Fitzhardinge
2007-02-13 23:58       ` [Xen-devel] " Zachary Amsden
2007-02-13 23:58       ` Dan Hecht
     [not found] ` <20070213221830.238235953@goop.org>
2007-02-14  1:06   ` [patch 10/21] Xen-paravirt: Name: dont export paravirt_ops structure, do individual functions Zachary Amsden
2007-02-14  1:16     ` Jeremy Fitzhardinge
2007-02-14  1:18       ` Zachary Amsden
2007-02-14  1:37         ` Jeremy Fitzhardinge
2007-02-14  1:43           ` Zachary Amsden
2007-02-14  1:44             ` Jeremy Fitzhardinge
2007-02-14  5:51     ` Rusty Russell
2007-02-14 19:36     ` Christoph Hellwig
     [not found] ` <20070213221829.845132535@goop.org>
2007-02-14  1:23   ` [patch 05/21] Xen-paravirt: paravirt_ops: allocate a fixmap slot Dan Hecht
2007-02-14  1:36     ` Jeremy Fitzhardinge
2007-02-14  2:34       ` Dan Hecht
2007-02-14  8:43         ` Gerd Hoffmann
2007-02-14  8:37       ` [Xen-devel] " Jan Beulich
2007-02-14  9:15         ` Andi Kleen
     [not found] ` <20070213221829.513618819@goop.org>
2007-02-14  9:24   ` [patch 02/21] Xen-paravirt: Handle a zero-sized VT console Gerd Hoffmann
     [not found] ` <20070213221830.707197267@goop.org>
2007-02-13 23:54   ` [patch 16/21] Xen-paravirt: Add code into head.S to handle being booted by Xen Andi Kleen
2007-02-14  0:39     ` Jeremy Fitzhardinge
2007-02-14  8:56       ` [Xen-devel] " Jan Beulich
2007-02-14 18:53     ` Jeremy Fitzhardinge
2007-02-14 20:10       ` Eric W. Biederman
2007-02-14 20:41         ` Jeremy Fitzhardinge
2007-02-14 21:06           ` Eric W. Biederman
2007-02-15  0:13             ` Jeremy Fitzhardinge
2007-02-15  1:39               ` Eric W. Biederman
2007-02-15  1:52                 ` Jeremy Fitzhardinge
2007-02-15  2:18                   ` Eric W. Biederman
2007-02-15  2:23                     ` Jeremy Fitzhardinge
2007-02-15  2:41                       ` Eric W. Biederman
2007-02-14 20:33   ` Eric W. Biederman
2007-02-14 20:42     ` Jeremy Fitzhardinge
     [not found] ` <20070213221831.150207238@goop.org>
2007-02-14 20:40   ` [patch 21/21] Xen-paravirt: Add the Xen virtual network device driver Eric W. Biederman
     [not found] ` <20070213221830.619562494@goop.org>
2007-02-14 20:45   ` [patch 15/21] Xen-paravirt: Add Xen interface header files Eric W. Biederman
2007-02-15  0:10     ` Jeremy Fitzhardinge
2007-02-15 17:32       ` Christoph Hellwig
2007-02-16  2:24 [patch 00/21] Xen-paravirt: Xen guest implementation for paravirt_ops interface Jeremy Fitzhardinge
2007-02-16  2:25 ` [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options Jeremy Fitzhardinge
2007-02-16  6:14   ` Dan Hecht
2007-02-16  7:04     ` Jeremy Fitzhardinge
2007-02-16  7:52       ` Dan Hecht
2007-02-16  8:05         ` Jeremy Fitzhardinge
2007-02-16  8:37           ` Dan Hecht
2007-02-16 10:49             ` Keir Fraser
2007-02-16  7:06     ` Andrew Morton
2007-02-16  7:25       ` Jeremy Fitzhardinge
2007-02-16 10:09         ` Keir Fraser
2007-02-16  6:15   ` Zachary Amsden
2007-02-16  7:33     ` Eric W. Biederman
2007-02-16  8:14       ` Ian Campbell
2007-02-16  8:24         ` Eric W. Biederman
2007-02-16  8:31           ` Zachary Amsden
2007-02-18 11:32     ` Avi Kivity

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