On Wed, Jan 29, 2025 at 09:17:38AM -0800, Stephen Hemminger wrote:
> On Wed, 29 Jan 2025 10:54:16 +0200
> Shani Peretz <shper...@nvidia.com> wrote:
>
> > DPDK provides two formats for specifying PCI device numbers:
> > a full version ("0000:08:00.0") and a short version ("08:00.0").
> > Issues can occur when an application uses one format (e.g., short)
> > while running testpmd, then attempts to use the other format
> > (e.g., full) in a later command, resulting in a failure.
> >
> > The issue is that find_device goes over the list of devices and
> > compares the user-provided string to the rte_device structure's
> > device->name (device->name is just the string received from devargs
> > (i.e "08:00.0" or "0000:08:00.0")).
> > Notice that there's another field that represents the device name,
> > but this one is in the rte_pci_bus struct. This name is actually the result
> > of the PCI parse function ("0000:08:00.0").
> > If we want to accurately compare these names, we'll need to bring both
> > sides to the same representation by invoking the parse function on
> > the user input.
> >
> > To make the cmp_dev_name function applicable to all buses—not just PCI—
> > the proposed solution is to utilize the parse function implemented by
> > each bus. When comparing names, we will call parse on the supplied
> > string as well as on the device name itself and compare the results.
> > This will allow consistent comparisons between different representations
> > of same devices.
> >
> > Also, the pci_common_set function has been modified to improve naming
> > consistency for PCI buses.
> > Now, the name stored in rte_device for PCI buses will match the parsed
> > name that is also stored in rte_pci_device name,
> > rather than using the user-provided string from devargs.
> > As a result, when a new PCI device is registered, the name displayed in
> > the device list will be the parsed version.
> >
> > Added tests that compare and find devices in various forms of names
> > under test_devargs.
> >
> > Fixes: a3ee360f4440 ("eal: add hotplug add/remove device")
>
> Maybe just fix for now by normalizing the PCI device string when before
> storing and after parsing? That would allow for simple fix that can be
> backported.
> The more complex generalization of bus address is too much to go to stable
> branch.
One idea for backport, perhaps?
https://patches.dpdk.org/project/dpdk/patch/20241119155723.2307189-1-bruce.richard...@intel.com/
