From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [PATCH v3] pci: correct pci config size default for cap version 2 endpoints Date: Fri, 22 Jul 2011 15:30:31 -0600 Message-ID: <1311370232.2653.100.camel@bling.home> References: <20110722155338.43049.12587.stgit@dddsys0.bos.redhat.com> <20110722212422.GH9766@sequoia.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Donald Dutile , kvm@vger.kernel.org, mst@redhat.com To: Chris Wright Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55249 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932200Ab1GVVaf (ORCPT ); Fri, 22 Jul 2011 17:30:35 -0400 In-Reply-To: <20110722212422.GH9766@sequoia.sous-sol.org> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, 2011-07-22 at 14:24 -0700, Chris Wright wrote: > * Donald Dutile (ddutile@redhat.com) wrote: > > diff --git a/hw/device-assignment.c b/hw/device-assignment.c > > index 36ad6b0..34db52e 100644 > > --- a/hw/device-assignment.c > > +++ b/hw/device-assignment.c > > @@ -1419,16 +1419,18 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev) > > } > > > > if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_EXP, 0))) { > > - uint8_t version; > > + uint8_t version, size; > > uint16_t type, devctl, lnkcap, lnksta; > > uint32_t devcap; > > - int size = 0x3c; /* version 2 size */ > > > > version = pci_get_byte(pci_dev->config + pos + PCI_EXP_FLAGS); > > version &= PCI_EXP_FLAGS_VERS; > > if (version == 1) { > > size = 0x14; > > - } else if (version > 2) { > > + } else if (version == 2) { > > + /* don't include slot cap/stat/ctrl 2 regs; only support endpoints */ > > + size = 0x34; > > That doesn't look correct to me. The size is fixed, just that some > registers are Reserved Zero when they do not apply (e.g. endpoint only). Apparently it can be interpreted differently. In this case, we've seen a tg3 device expose a v2 PCI express capability at offset 0xcc. Using 0x3c bytes, we extend 8 bytes past the legacy config space area :( Alex