On Fri, Jun 1, 2018 at 2:50 AM, Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote: > When specifying PCI devices on the kernel command line using a > BDF, the bus numbers can change when adding or replacing a device, > changing motherboard firmware, or applying kernel parameters like > pci=assign-buses. When this happens, it is usually undesirable to > apply whatever command line tweak to the wrong device. > > Therefore, it is useful to be able to specify devices with a base > bus number and the path of devfns needed to get to it. (Similar to > the "device scope" structure in the Intel VT-d spec, Section 8.3.1.) > > Thus, we add an option to specify devices in the following format: > > path:[<domain>:]<bus>:<slot>.<func>/<slot>.<func>[/ ...] > > The path can be any segment within the PCI hierarchy of any length and > determined through the use of 'lspci -t'. When specified this way, it is > less likely that a renumbered bus will result in a valid device specification > and the tweak won't be applied to the wrong device. > > Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Reviewed-by: Stephen Bates <sbates@xxxxxxxxxxxx> > Acked-by: Christian König <christian.koenig@xxxxxxx> > - specified in one of two formats: > + specified in one of three formats: ...in one of the following formats: in the first place and don't fix it each time you add/remove one? -- With Best Regards, Andy Shevchenko
