From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37719) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XXAe9-00008p-3z for qemu-devel@nongnu.org; Thu, 25 Sep 2014 11:07:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XXAe4-0006gV-Ad for qemu-devel@nongnu.org; Thu, 25 Sep 2014 11:07:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6287) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XXAe4-0006fU-1d for qemu-devel@nongnu.org; Thu, 25 Sep 2014 11:07:48 -0400 Date: Thu, 25 Sep 2014 16:07:34 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20140925150734.GJ2348@work-vm> References: <1400518826-19144-1-git-send-email-dgilbert@redhat.com> <1400571640.10626.7.camel@nilsson.home.kraxel.org> <20140520084725.GA2538@work-vm> <20140520091802.GP1302@redhat.com> <1400580641.29693.8.camel@nilsson.home.kraxel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH] -machine vmport=off: Allow disabling of VMWare ioport emulation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Slutz, Donald Christopher" Cc: "mst@redhat.com" , "qemu-devel@nongnu.org" , "armbru@redhat.com" , "Richard W.M. Jones" , Gerd Hoffmann , "aliguori@amazon.com" , Anthony PERARD * Slutz, Donald Christopher (dslutz@verizon.com) wrote: > What is happening with this patch? I would like to use this code. I need to rework it for the new machine types code; but it was pretty low down my list of priorities; but I can try and get a minute for it again. Dave > > -Don Slutz > > ________________________________________ > From: qemu-devel-bounces+don=cloudswitch.com@nongnu.org [qemu-devel-bounces+don=cloudswitch.com@nongnu.org] on behalf of Gerd Hoffmann [kraxel@redhat.com] > Sent: Tuesday, May 20, 2014 6:10 AM > To: Richard W.M. Jones > Cc: mst@redhat.com; qemu-devel@nongnu.org; armbru@redhat.com; Dr. David Alan Gilbert; aliguori@amazon.com; Anthony PERARD > Subject: Re: [Qemu-devel] [PATCH] -machine vmport=off: Allow disabling of VMWare ioport emulation > > Hi, > > > It was disabled in this patch. The commit message is saying that > > vmport cannot work in Xen, but I'm not exactly clear why. > > > > commit 1611977c3d8fdbdac6090cbd1f5555cee4aed6d9 > > Author: Anthony PERARD > > Date: Tue May 3 17:06:54 2011 +0100 > > > > pc, Disable vmport initialisation with Xen. > > > > This is because there is not synchronisation of the vcpu register > > between Xen and QEMU, so vmport can't work properly. > > Ah, ok. The backdoor has side effects (writing the port does modify > vcpu registers). That is the bit which is problematic for xen. Scratch > the idea then. > > Original patch is fine. > > Reviewed-by: Gerd Hoffmann > > cheers, > Gerd > > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK