On Tue, 24 Feb 2026 19:39:42 -0800 Dimon Zhao <[email protected]> wrote:
> Due to a chip design limitation, only the VF > supports the igb_uio driver. The PF does not. > > The igb_uio driver requires allocating interrupts and configuring the > PCIe MSI-X table before the driver's probe function is called. > This pre-probe configuration is only possible on the VF due to the > hardware limitation; the PF can only configure the MSI-X table during > its probe process. > > Therefore, using igb_uio on the PF will fail. > This commit clarifies this restriction. > > Signed-off-by: Dimon Zhao <[email protected]> > --- > doc/guides/nics/nbl.rst | 11 ++++ > doc/guides/rel_notes/release_26_03.rst | 4 ++ > drivers/net/nbl/nbl_core.c | 2 + > drivers/net/nbl/nbl_dev/nbl_dev.c | 33 ++++++++++-- > drivers/net/nbl/nbl_dev/nbl_dev.h | 3 ++ > drivers/net/nbl/nbl_dispatch.c | 50 +++++++++++++++++++ > drivers/net/nbl/nbl_ethdev.c | 13 +++++ > .../nbl_hw/nbl_hw_leonis/nbl_hw_leonis_snic.c | 12 +++++ > .../nbl_hw/nbl_hw_leonis/nbl_hw_leonis_snic.h | 9 ++++ > .../nbl/nbl_hw/nbl_hw_leonis/nbl_res_leonis.c | 10 ++++ > drivers/net/nbl/nbl_include/nbl_def_channel.h | 5 ++ > .../net/nbl/nbl_include/nbl_def_dispatch.h | 3 ++ > drivers/net/nbl/nbl_include/nbl_def_hw.h | 3 ++ > .../net/nbl/nbl_include/nbl_def_resource.h | 3 ++ > 14 files changed, 157 insertions(+), 4 deletions(-) > > diff --git a/doc/guides/nics/nbl.rst b/doc/guides/nics/nbl.rst > index ba0a119dfd..c74826a3c2 100644 > --- a/doc/guides/nics/nbl.rst > +++ b/doc/guides/nics/nbl.rst > @@ -101,3 +101,14 @@ Limitations or Known Issues > 32-bit architectures are not supported. > > Windows and BSD are not supported yet. > + > +**igb_uio Driver Support** > + > +Due to chip design limitations, only the VF supports the ``igb_uio`` driver, > +PF does not support this driver. > + > +**uio_pci_generic Driver Support** > + > +The ``uio_pci_generic`` driver is not supported on either PF or VF devices. > +This is because the NBL PMD requires MSI-X interrupts to receive mailbox > +messages, but the ``uio_pci_generic`` driver does not support MSI-X > interrupts. The igb_uio driver is deprecated at this point, it is not upstream and has lots of issues. Can VFIO be used in no IOMMU mode for this instead?
