On Thu, Jun 8, 2023 at 12:59 PM David Marchand <david.march...@redhat.com> wrote: > > On Thu, Jun 8, 2023 at 7:38 AM Jerin Jacob <jerinjac...@gmail.com> wrote: > > > > On Thu, Jun 8, 2023 at 2:31 AM Abdullah Sevincer > > <abdullah.sevin...@intel.com> wrote: > > > > > > vfio-pci driver in Linux kernel 6.2 enables PASID by default. > > > In DLB hardware, enabling PASID puts DLB in SIOV mode. This > > > breaks DLB PF-PMD mode. For DLB PF-PMD mode to function properly > > > PASID needs to be disabled for kernel 6.2. > > > > > > In this commit this issue is addressed and PASID is disabled > > > by writing a zero to PASID control register. > > > > > > Signed-off-by: Abdullah Sevincer <abdullah.sevin...@intel.com> > > > > > + /* The current Linux kernel vfio driver does not expose PASID > > > capability to > > > + * users. It also enables PASID by default, which breaks DLB PF > > > PMD. We have > > > + * to use the hardcoded offset for now to disable PASID. > > > + */ > > > + pasid_cap_offset = DLB2_PCI_PASID_CAP_OFFSET; > > > + > > > + off = pasid_cap_offset + DLB2_PCI_PASID_CTRL; > > > > +++ additional folks. > > > > Is make sense to move this helper function to PCI common for disabling > > PASID for a PCI device so that other driver can use if needed > > as the implementation is not specific to DLB2. > > Yes, having a helper sounds like a first step (and we probably have > more helpers to add seeing how drivers tend to redefine non vendor > specific pci configs, but that's another story).
@Abdullah Sevincer Please move the implementation to code PCI code. > > Now, about PASID being enabled by default with Linux 6.2, is this > breaking of dlb PF something special? Or can we expect many (all?) > other devices to break too? > If so, maybe we should disable it in the pci common code. @Abdullah Sevincer Is implicitly enabling SIOV based on PASID configuration DLB2 behavior or general PCI behavior that may affect other NIC's? > > > -- > David Marchand >
