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| author | Alex Mastro <amastro@fb.com> | 2026-01-14 10:57:17 -0800 |
|---|---|---|
| committer | Alex Williamson <alex@shazbot.org> | 2026-01-19 10:06:30 -0700 |
| commit | 557dbdf6c4e9c2dc3d4a4476c67ef14dca32378d (patch) | |
| tree | ccf91df662c70513326a45c4cfa74cb49158b14e /tools/testing/selftests/vfio/lib/include | |
| parent | 03b7c2d763c907f508edf8c317c0e920ce072a33 (diff) | |
| download | linux-557dbdf6c4e9c2dc3d4a4476c67ef14dca32378d.tar.gz linux-557dbdf6c4e9c2dc3d4a4476c67ef14dca32378d.zip | |
vfio: selftests: Align BAR mmaps for efficient IOMMU mapping
Update vfio_pci_bar_map() to align BAR mmaps for efficient huge page
mappings. The manual mmap alignment can be removed once mmap(!MAP_FIXED)
on vfio device fds improves to automatically return well-aligned
addresses.
Also add MADV_HUGEPAGE, which encourages the kernel to use huge pages
(e.g. when /sys/kernel/mm/transparent_hugepage/enabled is set to "madvise").
Drop MAP_FILE from mmap(). It is an ignored compatibility flag.
Signed-off-by: Alex Mastro <amastro@fb.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Tested-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20260114-map-mmio-test-v3-2-44e036d95e64@fb.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Diffstat (limited to 'tools/testing/selftests/vfio/lib/include')
| -rw-r--r-- | tools/testing/selftests/vfio/lib/include/libvfio.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/tools/testing/selftests/vfio/lib/include/libvfio.h b/tools/testing/selftests/vfio/lib/include/libvfio.h index 279ddcd70194..1b6da54cc2cb 100644 --- a/tools/testing/selftests/vfio/lib/include/libvfio.h +++ b/tools/testing/selftests/vfio/lib/include/libvfio.h @@ -23,4 +23,13 @@ const char *vfio_selftests_get_bdf(int *argc, char *argv[]); char **vfio_selftests_get_bdfs(int *argc, char *argv[], int *nr_bdfs); +/* + * Reserve virtual address space of size at an address satisfying + * (vaddr % align) == offset. + * + * Returns the reserved vaddr. The caller is responsible for unmapping + * the returned region. + */ +void *mmap_reserve(size_t size, size_t align, size_t offset); + #endif /* SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_H */ |