Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757711Ab0LBOmh (ORCPT ); Thu, 2 Dec 2010 09:42:37 -0500 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:22825 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757394Ab0LBOmg (ORCPT ); Thu, 2 Dec 2010 09:42:36 -0500 X-IronPort-AV: E=Sophos;i="4.59,288,1288569600"; d="scan'208";a="3156064" Date: Thu, 2 Dec 2010 14:42:28 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball-desktop To: Jeremy Fitzhardinge CC: Stefano Stabellini , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , Jeremy Fitzhardinge Subject: Re: [Xen-devel] [PATCH 0/5] Xen PV on HVM fixes In-Reply-To: <4CF69840.3040704@goop.org> Message-ID: References: <4CF69840.3040704@goop.org> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2074 Lines: 53 On Wed, 1 Dec 2010, Jeremy Fitzhardinge wrote: > On 12/01/2010 10:22 AM, Stefano Stabellini wrote: > > Hi all, > > this patch series is a collection of fixes for Xen PV on HVM. > > > > The first two patches fix two pirq remapping problems with MSIs, they > > have been sent to the list few times already for comments. > > The three following patches are new and fix save/restore bugs. > > Are you targeting these at 3.6.37-rc? Yes, because the bugs are pretty serious. > If so, each changelog commit > should explicitly say what bug is being fixed, and what the impact of > the bug is. The last 3 are OK, but it isn't clear to me whether the > first two are strictly bugfixes or not. > The first patch fixes find_unbound_pirq that otherwise would be based on PHYSDEVOP_get_nr_pirqs that is actually not supported by Xen, therefore it would fail. So find_unbound_pirq would return a number starting from nr_irqs that might very well be out of range in Xen. The symptom of this bug is that when you passthrough an MSI capable pci device to a PV on HVM guest, Linux would fail to enable MSIs on the device. The second patch fixes a bug in xen_hvm_setup_msi_irqs that manifests itself when trying to enable the same MSI for the second time: qemu is responsible for remapping MSIs into pirqs and considers the old MSI to pirq mapping still valid at this point but xen_hvm_setup_msi_irqs would try to assign a new pirq anyway. A simple way to reproduce this bug is to assign an MSI capable network card to a PV on HVM guest, if the user brings down the corresponding ethernet interface and up again, Linux would fail to enable MSIs on the device. I have updated the first two commit messages with these info, the branch is still the same: git://xenbits.xen.org/people/sstabellini/linux-pvhvm.git 2.6.37-rc4-pvhvm-fixes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/