Re: [PATCH v2 1/2] drivers/vfio_pci_core: Change PXD_ORDER check from switch case to if/else block
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From: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Date: 2026-03-09 14:24:25
Also in:
kvm, linux-mm
Le 09/03/2026 à 13:38, 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) <ritesh.list@gmail.com>Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
quoted hunk ↗ jump to hunk
--- v1 -> v2: 1. addressed review comments from Christophe [1] [1]: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flinuxppc-dev%2F0b8fce7a61561640634317a5e287cdb4794715fd.1772170860.git.ritesh.list%40gmail.com%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C2525bc52e4e645e2fb0208de7dd8d236%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639086567353080039%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=DZuZX3hss7yYqBwYz61VgEY6J%2F7OuLViaTMYP43VoBY%3D&reserved=0 drivers/vfio/pci/vfio_pci_core.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-)diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index d43745fe4c84..0967307235b8 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c@@ -1670,21 +1670,16 @@ 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) return vmf_insert_pfn(vmf->vma, vmf->address, pfn); -#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP - case PMD_ORDER: + + if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_PMD_PFNMAP) && order == PMD_ORDER) return vmf_insert_pfn_pmd(vmf, pfn, false); -#endif -#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP - case PUD_ORDER: + + if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_PUD_PFNMAP) && order == PUD_ORDER) return vmf_insert_pfn_pud(vmf, pfn, false); - break; -#endif - default: - return VM_FAULT_FALLBACK; - } + + return VM_FAULT_FALLBACK; } EXPORT_SYMBOL_GPL(vfio_pci_vmf_insert_pfn); --2.39.5