Re: [libvirt] [PATCH] Read PCI class from sysfs class file instead of config space.

On Tue, Dec 10, 2013 at 07:57:01AM -0200, Thadeu Lima de Souza Cascardo wrote: > When determining if a device is behind a PCI bridge, the PCI device > class is checked by reading the config space. However, there are some > devices which have the wrong class on the config space, but the class is > initialized by Linux correctly as a PCI BRIDGE. This class can be read > by the sysfs file '/sys/bus/pci/devices/xxxx:xx:xx.x/class'. Do you have any idea how long this file has been present in sysfs ? Hopefully it is a fairly ancient feature, so we can rely on it existing ? Otherwise we'll need to fallback to reading the config space when the sysfs file does not exist.

> One example of such bridge is IBM PCI Bridge 1014:03b9, which is > identified as a Host Bridge when reading the config space. > > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)linux.vnet.ibm.com&gt; > --- > src/util/virpci.c | 38 +++++++++++++++++++++++++++++++++++--- > 1 files changed, 35 insertions(+), 3 deletions(-) Looks reasonable to me, though prefer Laine to ACK it since he knows the PCI code best of anyone

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