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557dbdf6c4
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>
104 lines
2.3 KiB
C
104 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <linux/align.h>
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#include "../../../kselftest.h"
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#include <libvfio.h>
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static bool is_bdf(const char *str)
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{
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unsigned int s, b, d, f;
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int length, count;
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count = sscanf(str, "%4x:%2x:%2x.%2x%n", &s, &b, &d, &f, &length);
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return count == 4 && length == strlen(str);
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}
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static char **get_bdfs_cmdline(int *argc, char *argv[], int *nr_bdfs)
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{
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int i;
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for (i = *argc - 1; i > 0 && is_bdf(argv[i]); i--)
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continue;
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i++;
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*nr_bdfs = *argc - i;
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*argc -= *nr_bdfs;
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return *nr_bdfs ? &argv[i] : NULL;
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}
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static char *get_bdf_env(void)
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{
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char *bdf;
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bdf = getenv("VFIO_SELFTESTS_BDF");
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if (!bdf)
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return NULL;
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VFIO_ASSERT_TRUE(is_bdf(bdf), "Invalid BDF: %s\n", bdf);
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return bdf;
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}
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char **vfio_selftests_get_bdfs(int *argc, char *argv[], int *nr_bdfs)
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{
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static char *env_bdf;
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char **bdfs;
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bdfs = get_bdfs_cmdline(argc, argv, nr_bdfs);
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if (bdfs)
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return bdfs;
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env_bdf = get_bdf_env();
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if (env_bdf) {
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*nr_bdfs = 1;
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return &env_bdf;
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}
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fprintf(stderr, "Unable to determine which device(s) to use, skipping test.\n");
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fprintf(stderr, "\n");
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fprintf(stderr, "To pass the device address via environment variable:\n");
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fprintf(stderr, "\n");
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fprintf(stderr, " export VFIO_SELFTESTS_BDF=\"segment:bus:device.function\"\n");
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fprintf(stderr, " %s [options]\n", argv[0]);
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fprintf(stderr, "\n");
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fprintf(stderr, "To pass the device address(es) via argv:\n");
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fprintf(stderr, "\n");
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fprintf(stderr, " %s [options] segment:bus:device.function ...\n", argv[0]);
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fprintf(stderr, "\n");
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exit(KSFT_SKIP);
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}
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const char *vfio_selftests_get_bdf(int *argc, char *argv[])
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{
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int nr_bdfs;
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return vfio_selftests_get_bdfs(argc, argv, &nr_bdfs)[0];
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}
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void *mmap_reserve(size_t size, size_t align, size_t offset)
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{
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void *map_base, *map_align;
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size_t delta;
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VFIO_ASSERT_GT(align, offset);
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delta = align - offset;
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map_base = mmap(NULL, size + align, PROT_NONE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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VFIO_ASSERT_NE(map_base, MAP_FAILED);
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map_align = (void *)(ALIGN((uintptr_t)map_base + delta, align) - delta);
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if (map_align > map_base)
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VFIO_ASSERT_EQ(munmap(map_base, map_align - map_base), 0);
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VFIO_ASSERT_EQ(munmap(map_align + size, map_base + align - map_align), 0);
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return map_align;
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}
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