From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754492Ab3KGVsB (ORCPT ); Thu, 7 Nov 2013 16:48:01 -0500 Received: from mail-ie0-f174.google.com ([209.85.223.174]:35514 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752009Ab3KGVrx (ORCPT ); Thu, 7 Nov 2013 16:47:53 -0500 Date: Thu, 7 Nov 2013 14:47:50 -0700 From: Bjorn Helgaas To: Konrad Rzeszutek Wilk Cc: Konrad Rzeszutek Wilk , Sucheta Chakraborty , "linux-pci@vger.kernel.org" , "x86@kernel.org" , Zhenzhong Duan , "linux-kernel@vger.kernel.org" , Ingo Molnar , "H. Peter Anvin" , xen-devel@lists.xenproject.org, Thomas Gleixner Subject: Re: [Xen-devel] [PATCH] PCI: Introduce two new MSI infrastructure calls for masking/unmasking. Message-ID: <20131107214750.GB2955@google.com> References: <1383772616-23060-1-git-send-email-konrad.wilk@oracle.com> <20131107014215.GA27725@andromeda.dapyr.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131107014215.GA27725@andromeda.dapyr.net> 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 Wed, Nov 06, 2013 at 09:42:15PM -0400, Konrad Rzeszutek Wilk wrote: > On Wed, Nov 06, 2013 at 04:51:52PM -0700, Bjorn Helgaas wrote: > > [+cc Thomas, Ingo, Peter, x86 list] > > > > On Wed, Nov 6, 2013 at 2:16 PM, Konrad Rzeszutek Wilk > > wrote: > > > Certain platforms do not allow writes in the MSI-X bars > > > to setup or tear down vector values. To combat against > > > the generic code trying to write to that and either silently > > > being ignored or crashing due to the pagetables being marked r/o > > > this patch introduces a platform over-write. > > > > > > Note that we keep two separate, non-weak, functions > > > default_mask_msi_irqs() and default_mask_msix_irqs() for the > > > behavior of the arch_mask_msi_irqs() and arch_mask_msix_irqs(), > > > as the default behavior is needed by x86 PCI code. > > > > > > For Xen, which does not allow the guest to write to MSI-X > > > tables - as the hypervisor is solely responsible for setting > > > the vector values - we implement two nops. > > > > > > CC: Bjorn Helgaas > > > CC: Sucheta Chakraborty > > > CC: Zhenzhong Duan > > > Signed-off-by: Konrad Rzeszutek Wilk > > > > I think this is safe, and I'd like to squeeze it into the v3.13 merge > > window next week, since it supersedes three patches Zhenzhong has been > > trying to get in since July [1], and this patch is much simpler to > > understand. > > > > I *think* this also fixes an actual bug on Xen. Konrad, is there a > > bugzilla or any kind of email problem description that we can include > > here as a reference? I think there's a lost interrupt with qlcnic, > > but I don't know the details or what the failure looks like to a user. > > It is pretty catastrophic. Here is the console log when I pass in > a PCI device (with MSI-X) to the guest: Perfect, thanks! I put the log info in https://bugzilla.kernel.org/show_bug.cgi?id=64581 and put this in my pci/misc branch for v3.13. I added the following to the changelog: This fixes a Xen guest crash when passing a PCI device with MSI-X to the guest. See the bugzilla for more details. [bhelgaas: add bugzilla info] Reference: https://bugzilla.kernel.org/show_bug.cgi?id=64581 Let me know if this needs any tweaking. Bjorn