From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=40587 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PFPo2-0004Da-GJ for qemu-devel@nongnu.org; Mon, 08 Nov 2010 06:22:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PFPo1-0006Vg-Es for qemu-devel@nongnu.org; Mon, 08 Nov 2010 06:22:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47690) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PFPo1-0006VT-1y for qemu-devel@nongnu.org; Mon, 08 Nov 2010 06:22:33 -0500 Date: Mon, 8 Nov 2010 13:22:27 +0200 From: "Michael S. Tsirkin" Message-ID: <20101108112227.GA1075@redhat.com> References: <20101004215311.17070.54862.stgit@s20.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101004215311.17070.54862.stgit@s20.home> Subject: [Qemu-devel] Re: [PATCH] PCI: Bus number from the bridge, not the device List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: yamahata@valinux.co.jp, qemu-devel@nongnu.org On Mon, Oct 04, 2010 at 03:53:11PM -0600, Alex Williamson wrote: > pcibus_dev_print() was erroneously retrieving the device bus > number from the secondary bus number offset of the device > instead of the bridge above the device. This ends of landing > in the 2nd byte of the 3rd BAR for devices, which thankfully > is usually zero. pcibus_get_dev_path() copied this code, > inheriting the same bug. pcibus_get_dev_path() is used for > ramblock naming, so changing it can effect migration. However, > I've only seen this byte be non-zero for an assigned device, > which can't migrate anyway, so hopefully we won't run into > any issues. > > Signed-off-by: Alex Williamson Good catch. Applied. I don't really see why do we put the dev path in the bus object: why not let device supply its name? And I think this will affect nested bridges. However they are currently broken anyway: we really must convert to topological names as bus number is guest-assigned - they don't have to be unique, even. What does fixing this involve? Just changing pcibus_get_dev_path? > --- > > hw/pci.c | 5 ++--- > 1 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/hw/pci.c b/hw/pci.c > index 6d0934d..15416dd 100644 > --- a/hw/pci.c > +++ b/hw/pci.c > @@ -1940,8 +1940,7 @@ static void pcibus_dev_print(Monitor *mon, DeviceState *dev, int indent) > > monitor_printf(mon, "%*sclass %s, addr %02x:%02x.%x, " > "pci id %04x:%04x (sub %04x:%04x)\n", > - indent, "", ctxt, > - d->config[PCI_SECONDARY_BUS], > + indent, "", ctxt, pci_bus_num(d->bus), > PCI_SLOT(d->devfn), PCI_FUNC(d->devfn), > pci_get_word(d->config + PCI_VENDOR_ID), > pci_get_word(d->config + PCI_DEVICE_ID), > @@ -1965,7 +1964,7 @@ static char *pcibus_get_dev_path(DeviceState *dev) > char path[16]; > > snprintf(path, sizeof(path), "%04x:%02x:%02x.%x", > - pci_find_domain(d->bus), d->config[PCI_SECONDARY_BUS], > + pci_find_domain(d->bus), pci_bus_num(d->bus), > PCI_SLOT(d->devfn), PCI_FUNC(d->devfn)); > > return strdup(path); >