From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751092Ab1KGVNI (ORCPT ); Mon, 7 Nov 2011 16:13:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64446 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750722Ab1KGVNF (ORCPT ); Mon, 7 Nov 2011 16:13:05 -0500 Date: Mon, 7 Nov 2011 23:14:14 +0200 From: "Michael S. Tsirkin" To: Rusty Russell Cc: Sasha Levin , linux-kernel , kvm , virtualization , Anthony Liguori Subject: Re: virtio-pci new configuration proposal Message-ID: <20111107211413.GA11577@redhat.com> References: <20111104114033.GA21308@redhat.com> <1320409939.3334.6.camel@lappy> <20111104135113.GA24452@redhat.com> <1320414804.3334.13.camel@lappy> <20111104142338.GB24452@redhat.com> <1320418385.3334.25.camel@lappy> <20111106073007.GA7146@redhat.com> <1320611097.3299.10.camel@lappy> <20111106213849.GA14292@redhat.com> <871utktsuw.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871utktsuw.fsf@rustcorp.com.au> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2011 at 03:46:23PM +1030, Rusty Russell wrote: > On Sun, 6 Nov 2011 23:38:49 +0200, "Michael S. Tsirkin" wrote: > > On Sun, Nov 06, 2011 at 10:24:57PM +0200, Sasha Levin wrote: > > > On Sun, 2011-11-06 at 09:30 +0200, Michael S. Tsirkin wrote: > > > > On Fri, Nov 04, 2011 at 04:53:05PM +0200, Sasha Levin wrote: > > > > > > I guess my assumption is that most options will be in use, > > > > > > not discarded dead-ends. > > > > > > > > > > I don't know about that. 64 bit features would be pretty rare for now - > > > > > and I don't think that setting the alignment will be also enabled by > > > > > default. > > The truth is somewhere between. New features tend to be used, and > importantly, they have to be offered. > > Anyway, the *per-device* config part will be contiguous. So we're > talking about pci-specific features. > > So far, the only three things make sense to have in a capability list: > MSI-X, the upper 32 feature bits, and the per-device config. > > Thanks, > Rusty. You mean the queue # to MSI-X vector mapping? One thing to remember is that it must be in the same type of BAR as the queue selection, since by PCI rules MMIO writes aren't I think ordered with PIO writes (it doesn't matter with KVM but might with another hypervisor). -- MST