From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [RFC][PATCH 1/2] KVM: In-kernel PIT model Date: Mon, 21 Jan 2008 10:53:26 +0100 Message-ID: <47946B96.4040508@siemens.com> References: <200801211718.23664.sheng.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Avi Kivity To: "Yang, Sheng" Return-path: In-Reply-To: <200801211718.23664.sheng.yang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Yang, Sheng wrote: > --- /dev/null > +++ b/arch/x86/kvm/i8254.h ... > +#define PIT_BASE_ADDRESS 0x40 > +#define SPEAKER_BASE_ADDRESS 0x61 > +#define PIT_MEM_LENGTH 4 > +#define PIT_FREQ 1193181 The PIT may not be limited to x86 platforms. So I would propose to make the setup more generic and flexible. And I would move the code out of arch/x86, just the speaker support should remain there. I'm currently struggling with emulating a proprietary platform that has (among other specialties...) a different PIT base frequency, and I already had to patch user space qemu for customizable frequencies. Maybe this kernel extension is a good chance to generalize the PIT setup, and I would be happy to contribute to this if there is a consensus. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ------------------------------------------------------------------------- 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/