>On Wed, Dec 06, 2023 at 03:03:56PM -0400, Jason Gunthorpe wrote: >> On Wed, Dec 06, 2023 at 06:58:44PM +0000, Catalin Marinas wrote: >> > -------------8<---------------------------- >> > diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c >> > index 1929103ee59a..b89d2dfcd534 100644 >> > --- a/drivers/vfio/pci/vfio_pci_core.c >> > +++ b/drivers/vfio/pci/vfio_pci_core.c >> > @@ -1863,7 +1863,7 @@ int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma >> > * See remap_pfn_range(), called from vfio_pci_fault() but we can't >> > * change vm_flags within the fault handler. Set them now. >> > */ >> > - vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); >> > + vm_flags_set(vma, VM_VFIO | VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); >> > vma->vm_ops = &vfio_pci_mmap_ops; >> > >> > return 0; >> > diff --git a/include/linux/mm.h b/include/linux/mm.h >> > index 418d26608ece..6df46fd7836a 100644 >> > --- a/include/linux/mm.h >> > +++ b/include/linux/mm.h >> > @@ -391,6 +391,13 @@ extern unsigned int kobjsize(const void *objp); >> > # define VM_UFFD_MINOR VM_NONE >> > #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ >> > >> > +#ifdef CONFIG_64BIT >> > +#define VM_VFIO_BIT 39 >> > +#define VM_VFIO BIT(VM_VFIO_BIT) >> > +#else >> > +#define VM_VFIO VM_NONE >> > +#endif >> > + >> > /* Bits set in the VMA until the stack is in its final location */ >> > #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY) >> > -------------8<---------------------------- >> > >> > In KVM, Akita's patch would take this into account, not just rely on >> > "device==true". >> >> Yes, Ankit let's try this please. I would not call it VM_VFIO though >> >> VM_VFIO_ALLOW_WC ? > > Yeah. I don't really care about the name. Thanks, I will make the change to set the VM_VFIO_ALLOW_WC flag in vfio. Then make use of "device==true" and presence of the flag to decide on setting the S2 as NORMAL_NC.
