From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Donnelly Subject: Re: R/W HG memory mappings with kvm? Date: Fri, 10 Jul 2009 10:38:11 +1200 Message-ID: <5f370d430907091538t4285f57eua8f2e0756788c0a9@mail.gmail.com> References: <5f370d430907051541o752d3dbag80d5cb251e5e4d00@mail.gmail.com> <4A51A9F0.7000909@redhat.com> <5f370d430907071523t120da246wf366dbfbbac9169b@mail.gmail.com> <4A54225F.1050703@redhat.com> <4A551387.3000702@cs.ualberta.ca> <5f370d430907081501m60064c7dp23ebd4153c9050f1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Avi Kivity , kvm@vger.kernel.org To: Cam Macdonell Return-path: Received: from mail-gx0-f226.google.com ([209.85.217.226]:52604 "EHLO mail-gx0-f226.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbZGIWiM convert rfc822-to-8bit (ORCPT ); Thu, 9 Jul 2009 18:38:12 -0400 Received: by gxk26 with SMTP id 26so824375gxk.13 for ; Thu, 09 Jul 2009 15:38:11 -0700 (PDT) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Jul 9, 2009 at 6:01 PM, Cam Macdonell wrote= : >> Is there a corresponding qemu patch for the backend to the guest pci >> driver? > > Oops right. =A0 For some reason I can't my driver patch in patchwork. > > http://kerneltrap.org/mailarchive/linux-kvm/2009/5/7/5665734 Thanks for the link, I have read through the thread now. It seems very relevant to what I am doing. Have you found a link to your qemu-kvm backend patches? Or are you running your own git tree? I don't really know where to look. >> I'm curious how the buffer memory is allocated and how BAR >> accesses are handled from the host side. > > The memory for the device allocated as a POSIX shared memory object a= nd then > mmapped on to the allocated BAR region in Qemu's allocated memory. =A0= That's > actually one spot that needs a bit of fixing by passing the already > allocated memory object to qemu instead of mmapping on to it. Right, I would be passing the memory in pre-allocated as well, but should be a relatively simple change. Regards, Stephen.