vfio/pci: Fallback huge faults for unaligned pfn

The PFN must also be aligned to the fault order to insert a huge
pfnmap.  Test the alignment and fallback when unaligned.

Fixes: f9e54c3a2f ("vfio/pci: implement huge_fault support")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219619
Reported-by: Athul Krishna <athul.krishna.kr@protonmail.com>
Reported-by: Precific <precification@posteo.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Precific <precification@posteo.de>
Link: https://lore.kernel.org/r/20250102183416.1841878-1-alex.williamson@redhat.com
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Alex Williamson
2025-01-02 11:32:54 -07:00
parent fc033cf25e
commit 09dfc8a5f2

View File

@@ -1661,14 +1661,15 @@ static vm_fault_t vfio_pci_mmap_huge_fault(struct vm_fault *vmf,
unsigned long pfn, pgoff = vmf->pgoff - vma->vm_pgoff; unsigned long pfn, pgoff = vmf->pgoff - vma->vm_pgoff;
vm_fault_t ret = VM_FAULT_SIGBUS; vm_fault_t ret = VM_FAULT_SIGBUS;
if (order && (vmf->address & ((PAGE_SIZE << order) - 1) || pfn = vma_to_pfn(vma) + pgoff;
if (order && (pfn & ((1 << order) - 1) ||
vmf->address & ((PAGE_SIZE << order) - 1) ||
vmf->address + (PAGE_SIZE << order) > vma->vm_end)) { vmf->address + (PAGE_SIZE << order) > vma->vm_end)) {
ret = VM_FAULT_FALLBACK; ret = VM_FAULT_FALLBACK;
goto out; goto out;
} }
pfn = vma_to_pfn(vma);
down_read(&vdev->memory_lock); down_read(&vdev->memory_lock);
if (vdev->pm_runtime_engaged || !__vfio_pci_memory_enabled(vdev)) if (vdev->pm_runtime_engaged || !__vfio_pci_memory_enabled(vdev))
@@ -1676,18 +1677,18 @@ static vm_fault_t vfio_pci_mmap_huge_fault(struct vm_fault *vmf,
switch (order) { switch (order) {
case 0: case 0:
ret = vmf_insert_pfn(vma, vmf->address, pfn + pgoff); ret = vmf_insert_pfn(vma, vmf->address, pfn);
break; break;
#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
case PMD_ORDER: case PMD_ORDER:
ret = vmf_insert_pfn_pmd(vmf, __pfn_to_pfn_t(pfn + pgoff, ret = vmf_insert_pfn_pmd(vmf,
PFN_DEV), false); __pfn_to_pfn_t(pfn, PFN_DEV), false);
break; break;
#endif #endif
#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
case PUD_ORDER: case PUD_ORDER:
ret = vmf_insert_pfn_pud(vmf, __pfn_to_pfn_t(pfn + pgoff, ret = vmf_insert_pfn_pud(vmf,
PFN_DEV), false); __pfn_to_pfn_t(pfn, PFN_DEV), false);
break; break;
#endif #endif
default: default: