On Tue, May 21, 2024 at 02:14:58PM +0200, Niklas Schnelle wrote: > On s390 there is a virtual PCI device called ISM which has a few rather > annoying oddities. For one it claims to have a 256 TiB PCI BAR (not > a typo) which leads to any attempt to mmap() it failing during vmap. > > Even if one tried to map this "BAR" only partially the mapping would not > be usable on systems with MIO support enabled however. This is because > of another oddity in that this virtual PCI device does not support the > newer memory I/O (MIO) PCI instructions and legacy PCI instructions are > not accessible by user-space when MIO is in use. If this device needs to > be accessed by user-space it will thus need a vfio-pci variant driver. > Until then work around both issues by excluding resources which don't > fit between IOREMAP_START and IOREMAP_END in vfio_pci_probe_mmaps(). > > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> > --- > drivers/vfio/pci/vfio_pci_core.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Jason
