From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: User space for lapic2 Date: Tue, 10 Jul 2007 16:45:20 +0300 Message-ID: <46938D70.7060106@qumranet.com> References: <10EA09EFD8728347A513008B6B0DA77A01BD7933@pdsmsx411.ccr.corp.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 To: "Dong, Eddie" Return-path: In-Reply-To: <10EA09EFD8728347A513008B6B0DA77A01BD7933-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@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 Dong, Eddie wrote: >> If we release a kernel with pic but not lapic, and userspace that >> defaults to user-pic+lapic, then that kernel will not work >> with a newer >> userspace that defaults to in-kernel pic+lapic. >> >> We need to switch in one go. I don't mind checking in patches to the >> lapic2 branch, and continually rebasing it against master, but >> a release >> will only happen when everything works. >> > > I think the difference here is if we can leave the live migration to > future, we all agree lapic should be with pic together and that is > almost there. > > Does "everything works" here mean live migration works? > > Yes. I don't think live migration is particularly difficult. You need a APIs to read and write the PIC+LAPIC states, and you write the state into the qemu device model, which already supports migration. You can even live migrate from a userspace PIC+LAPIC to a kernel PIC+LAPIC as the format is the same. CPU registers work the same way in kvm/qemu. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/