From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57487) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TdUSp-0007kM-GU for qemu-devel@nongnu.org; Tue, 27 Nov 2012 18:21:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TdUSk-0005j9-4i for qemu-devel@nongnu.org; Tue, 27 Nov 2012 18:21:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:16970) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TdUSj-0005il-Sg for qemu-devel@nongnu.org; Tue, 27 Nov 2012 18:21:10 -0500 Message-ID: <1354058462.1809.182.camel@bling.home> From: Alex Williamson Date: Tue, 27 Nov 2012 16:21:02 -0700 In-Reply-To: <50B547F3.1080907@web.de> References: <20121127215203.5751.6523.stgit@bling.home> <50B547F3.1080907@web.de> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 0/4] MSI affinity for assigned devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org On Wed, 2012-11-28 at 00:08 +0100, Jan Kiszka wrote: > On 2012-11-27 23:00, Alex Williamson wrote: > > This is post-1.3 material, so I'll just post it as an RFC for now. > > > > MSI routing updates aren't currently handled by pci-assign or > > vfio-pci (when using KVM acceleration), which means that trying to > > set interrupt SMP affinity in the guest has no effect unless MSI is > > completely disabled and re-enabled. This series fixes this for both > > device assignment backends using similar schemes. We store the last > > MSIMessage programmed to KVM and do updates to the MSI route when it > > changes. pci-assign takes a little bit of refactoring to make this > > happen cleanly. Thanks, > > This should rather be done by implementing vector notifiers for MSI as > well. That way the device model no longer has to track reasons for > vector changes in an open-coded fashion, just like we already do for MSI-X. > > Was on my todo list for a long time, but I never reached this item. MSI masking is optional and not many devices seem to support it. What I see with a linux guest is that it just overwrites the address/data while MSI is enabled. What were you thinking for notifiers? mask, unmask, update? I'm not sure I'm interested enough in this to add MSI vector notifiers. Thanks, Alex