From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCHv4] device-assignment: don't touch pci command register Date: Wed, 18 Apr 2012 23:12:39 -0300 Message-ID: <20120419021239.GA17648@amt.cnet> References: <20120417121042.GA24138@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, Alex Williamson , Jan Kiszka , Avi Kivity To: "Michael S. Tsirkin" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8875 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484Ab2DSCQr (ORCPT ); Wed, 18 Apr 2012 22:16:47 -0400 Content-Disposition: inline In-Reply-To: <20120417121042.GA24138@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Apr 17, 2012 at 03:10:42PM +0300, Michael S. Tsirkin wrote: > Real command register is under kernel control: > it includes bits for triggering SERR, marking > BARs as invalid and such which are all under host > kernel control. > > While there's no known bug this triggers - since qemu does its > best to make guest state match device state - > it seems safer to avoid touching this register as much as > possible. > > With this patch, we don't touch any bits > except bus master which is ok to put under guest control > and intx mask which kvm interrupt sharing machinery > explicitly allows. > > Note: PCI_STATUS bears looking into as well. > > Tested-by: Alex Williamson > Signed-off-by: Michael S. Tsirkin Applied, thanks.