[RFC PATCH 17/39] KVM: selftests: Add basic selftests for hugetlb-backed guest_memfd

[Ackerley Tng]

Add tests for 2MB and 1GB page sizes, and update the invalid flags
test for the new KVM_GUEST_MEMFD_HUGETLB flag.

Signed-off-by: Ackerley Tng <ackerley...@google.com>

---
 .../testing/selftests/kvm/guest_memfd_test.c  | 45 ++++++++++++++-----
 1 file changed, 35 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c 
b/tools/testing/selftests/kvm/guest_memfd_test.c
index ba0c8e996035..3618ce06663e 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -13,6 +13,7 @@
 
 #include <linux/bitmap.h>
 #include <linux/falloc.h>
+#include <linux/kvm.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -122,6 +123,7 @@ static void test_invalid_punch_hole(int fd, size_t 
page_size, size_t total_size)
 
 static void test_create_guest_memfd_invalid(struct kvm_vm *vm)
 {
+       uint64_t valid_flags = KVM_GUEST_MEMFD_HUGETLB;
        size_t page_size = getpagesize();
        uint64_t flag;
        size_t size;
@@ -135,6 +137,9 @@ static void test_create_guest_memfd_invalid(struct kvm_vm 
*vm)
        }
 
        for (flag = 0; flag; flag <<= 1) {
+               if (flag & valid_flags)
+                       continue;
+
                fd = __vm_create_guest_memfd(vm, page_size, flag);
                TEST_ASSERT(fd == -1 && errno == EINVAL,
                            "guest_memfd() with flag '0x%lx' should fail with 
EINVAL",
@@ -170,24 +175,16 @@ static void test_create_guest_memfd_multiple(struct 
kvm_vm *vm)
        close(fd1);
 }
 
-int main(int argc, char *argv[])
+static void test_guest_memfd(struct kvm_vm *vm, uint32_t flags, size_t 
page_size)
 {
-       size_t page_size;
        size_t total_size;
        int fd;
-       struct kvm_vm *vm;
 
        TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD));
 
-       page_size = getpagesize();
        total_size = page_size * 4;
 
-       vm = vm_create_barebones();
-
-       test_create_guest_memfd_invalid(vm);
-       test_create_guest_memfd_multiple(vm);
-
-       fd = vm_create_guest_memfd(vm, total_size, 0);
+       fd = vm_create_guest_memfd(vm, total_size, flags);
 
        test_file_read_write(fd);
        test_mmap(fd, page_size);
@@ -197,3 +194,31 @@ int main(int argc, char *argv[])
 
        close(fd);
 }
+
+int main(int argc, char *argv[])
+{
+       struct kvm_vm *vm;
+
+       TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD));
+
+       vm = vm_create_barebones();
+
+       test_create_guest_memfd_invalid(vm);
+       test_create_guest_memfd_multiple(vm);
+
+       printf("Test guest_memfd with 4K pages\n");
+       test_guest_memfd(vm, 0, getpagesize());
+       printf("\tPASSED\n");
+
+       printf("Test guest_memfd with 2M pages\n");
+       test_guest_memfd(vm, KVM_GUEST_MEMFD_HUGETLB | KVM_GUEST_MEMFD_HUGE_2MB,
+                        2UL << 20);
+       printf("\tPASSED\n");
+
+       printf("Test guest_memfd with 1G pages\n");
+       test_guest_memfd(vm, KVM_GUEST_MEMFD_HUGETLB | KVM_GUEST_MEMFD_HUGE_1GB,
+                        1UL << 30);
+       printf("\tPASSED\n");
+
+       return 0;
+}
-- 
2.46.0.598.g6f2099f65c-goog