Le 27/02/2026 à 07:16, Ritesh Harjani (IBM) a écrit :
Architectures like PowerPC uses runtime defined values for
PMD_ORDER/PUD_ORDER. This is because it can use either RADIX or HASH MMU
at runtime using kernel cmdline. So the pXd_index_size is not known at
compile time. Without this fix, when we add huge pfn support on powerpc
in the next patch, vfio_pci_core driver compilation can fail with the
following errors.
CC [M] drivers/vfio/vfio_main.o
CC [M] drivers/vfio/group.o
CC [M] drivers/vfio/container.o
CC [M] drivers/vfio/virqfd.o
CC [M] drivers/vfio/vfio_iommu_spapr_tce.o
CC [M] drivers/vfio/pci/vfio_pci_core.o
CC [M] drivers/vfio/pci/vfio_pci_intrs.o
CC [M] drivers/vfio/pci/vfio_pci_rdwr.o
CC [M] drivers/vfio/pci/vfio_pci_config.o
CC [M] drivers/vfio/pci/vfio_pci.o
AR kernel/built-in.a
../drivers/vfio/pci/vfio_pci_core.c: In function ‘vfio_pci_vmf_insert_pfn’:
../drivers/vfio/pci/vfio_pci_core.c:1678:9: error: case label does not reduce
to an integer constant
1678 | case PMD_ORDER:
| ^~~~
../drivers/vfio/pci/vfio_pci_core.c:1682:9: error: case label does not reduce
to an integer constant
1682 | case PUD_ORDER:
| ^~~~
make[6]: *** [../scripts/Makefile.build:289: drivers/vfio/pci/vfio_pci_core.o]
Error 1
make[6]: *** Waiting for unfinished jobs....
make[5]: *** [../scripts/Makefile.build:546: drivers/vfio/pci] Error 2
make[5]: *** Waiting for unfinished jobs....
make[4]: *** [../scripts/Makefile.build:546: drivers/vfio] Error 2
make[3]: *** [../scripts/Makefile.build:546: drivers] Error 2
Fixes: f9e54c3a2f5b7 ("vfio/pci: implement huge_fault support")
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
drivers/vfio/pci/vfio_pci_core.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index d43745fe4c84..5395a6f30904 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1670,21 +1670,20 @@ vm_fault_t vfio_pci_vmf_insert_pfn(struct
vfio_pci_core_device *vdev,
if (vdev->pm_runtime_engaged || !__vfio_pci_memory_enabled(vdev))
return VM_FAULT_SIGBUS;
- switch (order) {
- case 0:
+ if (order == 0) {
return vmf_insert_pfn(vmf->vma, vmf->address, pfn);
+ }
Those braces are unneeded as all legs of the if/else are single lines
#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
ifdef could be replaced by IS_ENABLED() because PxD_ORDER and
vmf_insert_pfn_xxx() are declared all the time
- case PMD_ORDER:
+ else if (order == PMD_ORDER) {
'else' is not needed because every 'if' leads to a return statement
return vmf_insert_pfn_pmd(vmf, pfn, false);
+ }
#endif
#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
- case PUD_ORDER:
+ else if (order == PUD_ORDER) {
return vmf_insert_pfn_pud(vmf, pfn, false);
- break;
+ }
#endif
- default:
- return VM_FAULT_FALLBACK;
- }
+ return VM_FAULT_FALLBACK;
So at the end we should get something like:
if (!order)
return vmf_insert_pfn(vmf->vma, vmf->address, pfn);
if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_PMD_PFNMAP) && order == PMD_ORDER)
return vmf_insert_pfn_pmd(vmf, pfn, false);
if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_PUD_PFNMAP) && order == PMD_ORDER)
return vmf_insert_pfn_pud(vmf, pfn, false);
return VM_FAULT_FALLBACK;
}
EXPORT_SYMBOL_GPL(vfio_pci_vmf_insert_pfn);
--
2.53.0
