From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48041) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0l6V-0005j0-E0 for qemu-devel@nongnu.org; Thu, 12 May 2016 03:32:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b0l6P-0007kU-BS for qemu-devel@nongnu.org; Thu, 12 May 2016 03:32:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47106) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0l6P-0007k3-5l for qemu-devel@nongnu.org; Thu, 12 May 2016 03:32:09 -0400 Date: Thu, 12 May 2016 15:32:03 +0800 From: Peter Xu Message-ID: <20160512073203.GC4678@pxdev.xzpeter.org> References: <1462948831-931-1-git-send-email-peterx@redhat.com> <20160511065318.GA13293@pxdev.xzpeter.org> <20160512101020-mutt-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160512101020-mutt-send-email-mst@redhat.com> Subject: Re: [Qemu-devel] [PATCH] pci: fix requester id with PCI bridges List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org, rkrcmar@redhat.com, alex.williamson@redhat.com, jan.kiszka@web.de, pbonzini@redhat.com On Thu, May 12, 2016 at 10:11:31AM +0300, Michael S. Tsirkin wrote: > On Wed, May 11, 2016 at 02:53:18PM +0800, Peter Xu wrote: > > On Wed, May 11, 2016 at 02:40:30PM +0800, Peter Xu wrote: > > > Recently I encountered issue when debugging Intel IOMMU IR codes, > > > that interrupts are not working correctly with PCI bridges (reported > > > by Radim). This patch fixes the problem. I assume requester ID > > > should be the devfn on root PCI bus (that's how I understand it > > > before, and also in guest kernel, IRTE entry SID is filled in that > > > way), however I failed to find any good document to confirm > > > this. Please let me know if this is correct (or I made any > > > mistake). > > > > One thing to mention is that, this patch does *not* fix the problem > > if directly applied, because IR patchset introduced another patch > > that also need a similar fix. In case if there is someone (Radim?) > > who would like to try this patch, we need to apply this patch as > > well: > > > > ---8<--- > > > > diff --git a/target-i386/kvm.c b/target-i386/kvm.c > > index 80b3251..0876a1c 100644 > > --- a/target-i386/kvm.c > > +++ b/target-i386/kvm.c > > @@ -3342,7 +3342,8 @@ int kvm_arch_fixup_msi_route(struct kvm_irq_routing_entry *route, > > src.data = route->u.msi.data; > > > > ret = class->int_remap(iommu, &src, &dst, dev ? \ > > - pci_requester_id(dev) : X86_IOMMU_SID_INVALID); > > + pci_requester_id_recursive(dev) : \ > > + X86_IOMMU_SID_INVALID); > > if (ret) { > > trace_kvm_x86_fixup_msi_error(route->gsi); > > return 1; > > > > --->8--- > > > > This should be able to be applied directly onto IR v6 patchset as > > well. > > > > Thanks, > > > > -- peterx > > I really dislike the name pci_requester_id_recursive. Do you have better suggestion on this? :) > Are there cases where we need the original requester id value? > I am guessing not, and if I'm right we should just change the implementation > of pci_requester_id to DTRT. There are two other callers for it (besides the MSI one): - assigned_device_pci_cap_init() - do_pcie_aer_inject_error() For both the cases, I am not sure whether we can do the replacement. -- peterx