@@ -485,8 +485,10 @@ int main(int argc, char *argv[])
}
}
- TEST_ASSERT(p.uffd_mode != UFFDIO_REGISTER_MODE_MINOR || p.src_type == VM_MEM_SRC_SHMEM,
- "userfaultfd MINOR mode requires shared memory; pick a different -t");
+ if (p.uffd_mode == UFFDIO_REGISTER_MODE_MINOR &&
+ !backing_src_is_shared(p.src_type)) {
+ TEST_FAIL("userfaultfd MINOR mode requires shared memory; pick a different -t");
+ }
for_each_guest_mode(run_test, &p);
@@ -17,6 +17,7 @@
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
+#include <sys/mman.h>
#include "kselftest.h"
static inline int _no_printf(const char *format, ...) { return 0; }
@@ -85,6 +86,7 @@ enum vm_mem_backing_src_type {
VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB,
VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB,
VM_MEM_SRC_SHMEM,
+ VM_MEM_SRC_SHARED_HUGETLB,
NUM_SRC_TYPES,
};
@@ -101,4 +103,13 @@ size_t get_backing_src_pagesz(uint32_t i);
void backing_src_help(void);
enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name);
+/*
+ * Whether or not the given source type is shared memory (as opposed to
+ * anonymous).
+ */
+static inline bool backing_src_is_shared(enum vm_mem_backing_src_type t)
+{
+ return vm_mem_backing_src_alias(t)->flag & MAP_SHARED;
+}
+
#endif /* SELFTEST_KVM_TEST_UTIL_H */
@@ -758,8 +758,13 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
region->mmap_size += alignment;
region->fd = -1;
- if (src_type == VM_MEM_SRC_SHMEM) {
- region->fd = memfd_create("kvm_selftest", MFD_CLOEXEC);
+ if (backing_src_is_shared(src_type)) {
+ int memfd_flags = MFD_CLOEXEC;
+
+ if (src_type == VM_MEM_SRC_SHARED_HUGETLB)
+ memfd_flags |= MFD_HUGETLB;
+
+ region->fd = memfd_create("kvm_selftest", memfd_flags);
TEST_ASSERT(region->fd != -1,
"memfd_create failed, errno: %i", errno);
@@ -240,6 +240,16 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i)
.name = "shmem",
.flag = MAP_SHARED,
},
+ [VM_MEM_SRC_SHARED_HUGETLB] = {
+ .name = "shared_hugetlb",
+ /*
+ * No MAP_HUGETLB, we use MFD_HUGETLB instead. Since
+ * we're using "file backed" memory, we need to specify
+ * this when the FD is created, not when the area is
+ * mapped.
+ */
+ .flag = MAP_SHARED,
+ },
};
_Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES,
"Missing new backing src types?");
@@ -262,6 +272,7 @@ size_t get_backing_src_pagesz(uint32_t i)
case VM_MEM_SRC_ANONYMOUS_THP:
return get_trans_hugepagesz();
case VM_MEM_SRC_ANONYMOUS_HUGETLB:
+ case VM_MEM_SRC_SHARED_HUGETLB:
return get_def_hugetlb_pagesz();
default:
return MAP_HUGE_PAGE_SIZE(flag);
This lets us run the demand paging test on top of a shared hugetlbfs-backed area. The "shared" is key, as this allows us to exercise userfaultfd minor faults on hugetlbfs. Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> --- tools/testing/selftests/kvm/demand_paging_test.c | 6 ++++-- tools/testing/selftests/kvm/include/test_util.h | 11 +++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 9 +++++++-- tools/testing/selftests/kvm/lib/test_util.c | 11 +++++++++++ 4 files changed, 33 insertions(+), 4 deletions(-)