Test that invalid inputs for KVM_CREATE_GUEST_MEMFD, such as non-page-aligned page size and invalid flags, are rejected by the KVM_CREATE_GUEST_MEMFD with EINVAL

Signed-off-by: Ackerley Tng ackerleytng@google.com --- .../testing/selftests/kvm/guest_memfd_test.c | 49 +++++++++++++++++++ .../selftests/kvm/include/kvm_util_base.h | 11 ++++- 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index eb93c608a7e0..4d2b110ab0d6 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -8,6 +8,7 @@ #define _GNU_SOURCE #include "test_util.h" #include "kvm_util_base.h" +#include <linux/bitmap.h> #include <linux/falloc.h> #include <sys/mman.h> #include <sys/types.h> @@ -90,6 +91,52 @@ static void test_fallocate(int fd, size_t page_size, size_t total_size) TEST_ASSERT(!ret, "fallocate to restore punched hole should succeed"); }

+static void test_create_guest_memfd_invalid(struct kvm_vm *vm) +{ + uint64_t valid_flags = 0; + size_t page_size = getpagesize(); + uint64_t flag; + size_t size; + int fd; + + for (size = 1; size < page_size; size++) { + fd = __vm_create_guest_memfd(vm, size, 0); + TEST_ASSERT(fd == -1 && errno == EINVAL, + "guest_memfd() with non-page-aligned page size '0x%lx' should fail with EINVAL", + size); + } + + if (thp_configured()) { + for (size = page_size * 2; size < get_trans_hugepagesz(); size += page_size) { + fd = __vm_create_guest_memfd(vm, size, KVM_GUEST_MEMFD_ALLOW_HUGEPAGE); + TEST_ASSERT(fd == -1 && errno == EINVAL, + "guest_memfd() with non-hugepage-aligned page size '0x%lx' should fail with EINVAL", + size); + } + + valid_flags = KVM_GUEST_MEMFD_ALLOW_HUGEPAGE; + } + + for (flag = 1; flag; flag <<= 1) { + uint64_t bit; + + 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", + flag); + + for_each_set_bit(bit, &valid_flags, 64) { + fd = __vm_create_guest_memfd(vm, page_size, flag | BIT_ULL(bit)); + TEST_ASSERT(fd == -1 && errno == EINVAL, + "guest_memfd() with flags '0x%llx' should fail with EINVAL", + flag | BIT_ULL(bit)); + } + } +} +

int main(int argc, char *argv[]) { @@ -103,6 +150,8 @@ int main(int argc, char *argv[])

vm = vm_create_barebones();

+ test_create_guest_memfd_invalid(vm); + fd = vm_create_guest_memfd(vm, total_size, 0);

test_file_read_write(fd); diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index 39b38c75b99c..8bdfadd72349 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -474,7 +474,8 @@ static inline uint64_t vm_get_stat(struct kvm_vm *vm, const char *stat_name) }

void vm_create_irqchip(struct kvm_vm *vm); -static inline int vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size, + +static inline int __vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size, uint64_t flags) { struct kvm_create_guest_memfd gmem = { @@ -482,7 +483,13 @@ static inline int vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size, .flags = flags, };

- int fd = __vm_ioctl(vm, KVM_CREATE_GUEST_MEMFD, &gmem); + return __vm_ioctl(vm, KVM_CREATE_GUEST_MEMFD, &gmem); +} + +static inline int vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size, + uint64_t flags) +{ + int fd = __vm_create_guest_memfd(vm, size, flags);

TEST_ASSERT(fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_GUEST_MEMFD, fd)); return fd; -- 2.42.0.rc1.204.g551eb34607-goog