diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/kvm/guest_memfd_test.c | 161 |
1 files changed, 139 insertions, 22 deletions
diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index 341ba616cf55..b88f580b2fd6 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -13,6 +13,8 @@ #include <linux/bitmap.h> #include <linux/falloc.h> +#include <setjmp.h> +#include <signal.h> #include <sys/mman.h> #include <sys/types.h> #include <sys/stat.h> @@ -34,12 +36,83 @@ static void test_file_read_write(int fd) "pwrite on a guest_mem fd should fail"); } -static void test_mmap(int fd, size_t page_size) +static void test_mmap_supported(int fd, size_t page_size, size_t total_size) +{ + const char val = 0xaa; + char *mem; + size_t i; + int ret; + + mem = mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + TEST_ASSERT(mem == MAP_FAILED, "Copy-on-write not allowed by guest_memfd."); + + mem = mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT(mem != MAP_FAILED, "mmap() for guest_memfd should succeed."); + + memset(mem, val, total_size); + for (i = 0; i < total_size; i++) + TEST_ASSERT_EQ(READ_ONCE(mem[i]), val); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, + page_size); + TEST_ASSERT(!ret, "fallocate the first page should succeed."); + + for (i = 0; i < page_size; i++) + TEST_ASSERT_EQ(READ_ONCE(mem[i]), 0x00); + for (; i < total_size; i++) + TEST_ASSERT_EQ(READ_ONCE(mem[i]), val); + + memset(mem, val, page_size); + for (i = 0; i < total_size; i++) + TEST_ASSERT_EQ(READ_ONCE(mem[i]), val); + + ret = munmap(mem, total_size); + TEST_ASSERT(!ret, "munmap() should succeed."); +} + +static sigjmp_buf jmpbuf; +void fault_sigbus_handler(int signum) +{ + siglongjmp(jmpbuf, 1); +} + +static void test_fault_overflow(int fd, size_t page_size, size_t total_size) +{ + struct sigaction sa_old, sa_new = { + .sa_handler = fault_sigbus_handler, + }; + size_t map_size = total_size * 4; + const char val = 0xaa; + char *mem; + size_t i; + int ret; + + mem = mmap(NULL, map_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT(mem != MAP_FAILED, "mmap() for guest_memfd should succeed."); + + sigaction(SIGBUS, &sa_new, &sa_old); + if (sigsetjmp(jmpbuf, 1) == 0) { + memset(mem, 0xaa, map_size); + TEST_ASSERT(false, "memset() should have triggered SIGBUS."); + } + sigaction(SIGBUS, &sa_old, NULL); + + for (i = 0; i < total_size; i++) + TEST_ASSERT_EQ(READ_ONCE(mem[i]), val); + + ret = munmap(mem, map_size); + TEST_ASSERT(!ret, "munmap() should succeed."); +} + +static void test_mmap_not_supported(int fd, size_t page_size, size_t total_size) { char *mem; mem = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); TEST_ASSERT_EQ(mem, MAP_FAILED); + + mem = mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT_EQ(mem, MAP_FAILED); } static void test_file_size(int fd, size_t page_size, size_t total_size) @@ -120,26 +193,19 @@ 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) +static void test_create_guest_memfd_invalid_sizes(struct kvm_vm *vm, + uint64_t guest_memfd_flags, + size_t page_size) { - 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, + fd = __vm_create_guest_memfd(vm, size, guest_memfd_flags); + TEST_ASSERT(fd < 0 && errno == EINVAL, "guest_memfd() with non-page-aligned page size '0x%lx' should fail with EINVAL", size); } - - for (flag = BIT(0); flag; flag <<= 1) { - 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); - } } static void test_create_guest_memfd_multiple(struct kvm_vm *vm) @@ -171,30 +237,81 @@ static void test_create_guest_memfd_multiple(struct kvm_vm *vm) close(fd1); } -int main(int argc, char *argv[]) +static void test_guest_memfd_flags(struct kvm_vm *vm, uint64_t valid_flags) { - size_t page_size; - size_t total_size; + size_t page_size = getpagesize(); + uint64_t flag; int fd; - struct kvm_vm *vm; - TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD)); + for (flag = BIT(0); flag; flag <<= 1) { + fd = __vm_create_guest_memfd(vm, page_size, flag); + if (flag & valid_flags) { + TEST_ASSERT(fd >= 0, + "guest_memfd() with flag '0x%lx' should succeed", + flag); + close(fd); + } else { + TEST_ASSERT(fd < 0 && errno == EINVAL, + "guest_memfd() with flag '0x%lx' should fail with EINVAL", + flag); + } + } +} + +static void test_guest_memfd(unsigned long vm_type) +{ + uint64_t flags = 0; + struct kvm_vm *vm; + size_t total_size; + size_t page_size; + int fd; page_size = getpagesize(); total_size = page_size * 4; - vm = vm_create_barebones(); + vm = vm_create_barebones_type(vm_type); + + if (vm_check_cap(vm, KVM_CAP_GUEST_MEMFD_MMAP)) + flags |= GUEST_MEMFD_FLAG_MMAP; - test_create_guest_memfd_invalid(vm); test_create_guest_memfd_multiple(vm); + test_create_guest_memfd_invalid_sizes(vm, flags, page_size); - 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); + + if (flags & GUEST_MEMFD_FLAG_MMAP) { + test_mmap_supported(fd, page_size, total_size); + test_fault_overflow(fd, page_size, total_size); + } else { + test_mmap_not_supported(fd, page_size, total_size); + } + test_file_size(fd, page_size, total_size); test_fallocate(fd, page_size, total_size); test_invalid_punch_hole(fd, page_size, total_size); + test_guest_memfd_flags(vm, flags); + close(fd); + kvm_vm_free(vm); +} + +int main(int argc, char *argv[]) +{ + unsigned long vm_types, vm_type; + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD)); + + /* + * Not all architectures support KVM_CAP_VM_TYPES. However, those that + * support guest_memfd have that support for the default VM type. + */ + vm_types = kvm_check_cap(KVM_CAP_VM_TYPES); + if (!vm_types) + vm_types = BIT(VM_TYPE_DEFAULT); + + for_each_set_bit(vm_type, &vm_types, BITS_PER_TYPE(vm_types)) + test_guest_memfd(vm_type); } |