On Tue, May 21, 2024 at 02:14:57PM +0200, Niklas Schnelle wrote: > The s390 MMIO syscalls when using the classic PCI instructions do not > cause a page fault when follow_pte() fails due to the page not being > present. Besides being a general deficiency this breaks vfio-pci's mmap() > handling once VFIO_PCI_MMAP gets enabled as this lazily maps on first > access. Fix this by following a failed follow_pte() with > fixup_user_page() and retrying the follow_pte(). > > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> > --- > arch/s390/pci/pci_mmio.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Jason
