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charset="utf-8" Message-Id: <20261106-gmem-alternative-providers-v3-19-8484dde66a7e@google.com> References: <20261106-gmem-alternative-providers-v3-0-8484dde66a7e@google.com> In-Reply-To: <20261106-gmem-alternative-providers-v3-0-8484dde66a7e@google.com> To: Alexey Kardashevskiy , "Aneesh Kumar K.V" , Christian Brauner , David Hildenbrand , David Woodhouse , Fred Griffoul , Jacob Pan , Jianxiong Gao , John Starks , Michael Roth , Paolo Bonzini , Samiullah Khawaja , Sean Christopherson , Suzuki K Poulose , Tarun Sahu , Vishal Annapurve , Xu Yilun , Fuad Tabba Cc: kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, Ackerley Tng X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=ed25519-sha256; t=1794011809; l=9639; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=Ywv4Awh60QVQXfJ42x/j6i2G3l1UGcU6b4v8gcyWpig=; b=EDb+BOFfQuAMKC477YknSboSYEtvDUgYLwNAzDBtxOPsFifr+qxx1Kgb2Sjumi6KnTOEoFdoN NlP5Q12K2NNCUhaXa9Jue3uo1cBdclLvjJJyIG6fbL7MBuPn4X5T/9n X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com Content-Transfer-Encoding: 7bit From: Ackerley Tng Move create_tmpfs_pool_fd() into lib/test_util.c and declare it in include/test_util.h so it can be reused across selftests. Extend guest_memfd_conversions_test using fixture variants to run all conversion test cases against both native guest_memfd and tmpfs-backed guest_memfd instances. Signed-off-by: Ackerley Tng --- tools/testing/selftests/kvm/guest_memfd_test.c | 52 -------------------- tools/testing/selftests/kvm/include/test_util.h | 2 + tools/testing/selftests/kvm/lib/test_util.c | 56 ++++++++++++++++++++++ .../kvm/x86/guest_memfd_conversions_test.c | 49 +++++++++++++++++-- 4 files changed, 102 insertions(+), 57 deletions(-) diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index fd249445ce3cc..cbc2f309664b2 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -481,58 +481,6 @@ static void test_resource_fd_memfd(struct kvm_vm *vm) close(file_fd); } -static int create_tmpfs_pool_fd(const char *huge, bool noswap, size_t size) -{ - char size_str[32]; - char template[] = "/tmp/gmem_test_dir_XXXXXX"; - char *mount_dir; - int fs_fd, mnt_fd, dir_fd; - - TEST_ASSERT(size && IS_ALIGNED(size, page_size), - "Pool size '0x%zx' must be positive and page-aligned", size); - - fs_fd = syscall(__NR_fsopen, "tmpfs", FSOPEN_CLOEXEC); - TEST_ASSERT(fs_fd >= 0, "fsopen failed"); - - if (noswap) - TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_SET_FLAG, - "noswap", NULL, 0), "fsconfig noswap failed"); - - if (huge) - TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_SET_STRING, - "huge", huge, 0), "fsconfig huge failed"); - - snprintf(size_str, sizeof(size_str), "%zu", size); - TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_SET_STRING, - "size", size_str, 0), "fsconfig size failed"); - - TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_CMD_CREATE, - NULL, NULL, 0), "fsconfig create failed"); - - mnt_fd = syscall(__NR_fsmount, fs_fd, FSMOUNT_CLOEXEC, 0); - TEST_ASSERT(mnt_fd > 0, "fsmount failed"); - close(fs_fd); - - mount_dir = mkdtemp(template); - TEST_ASSERT(mount_dir, "mkdtemp failed"); - - TEST_ASSERT(!syscall(__NR_move_mount, mnt_fd, "", AT_FDCWD, mount_dir, - MOVE_MOUNT_F_EMPTY_PATH), "move_mount failed"); - close(mnt_fd); - - dir_fd = open(mount_dir, O_RDONLY | O_DIRECTORY | O_CLOEXEC); - TEST_ASSERT(dir_fd >= 0, "open tmpfs mount directory failed"); - - /* - * Detach mount from namespace so removing mount_dir upon exit or - * unmount doesn't conflict, while dir_fd retains the active mount. - */ - TEST_ASSERT(!umount2(mount_dir, MNT_DETACH), "umount2 failed"); - TEST_ASSERT(!rmdir(mount_dir), "rmdir failed"); - - return dir_fd; -} - static void test_resource_fd_tmpfs_swap(struct kvm_vm *vm) { int pool_fd, fd; diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index c80019e24b2d0..e6707534f1951 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -244,4 +244,6 @@ char *strdup_printf(const char *fmt, ...) __attribute__((format(printf, 1, 2), n char *sys_get_cur_clocksource(void); +int create_tmpfs_pool_fd(const char *huge, bool noswap, size_t size); + #endif /* SELFTEST_KVM_TEST_UTIL_H */ diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index f5f7189f96a84..c5b264f533ad0 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -10,10 +10,14 @@ #include #include #include +#include #include +#include #include #include +#include #include +#include #include "linux/kernel.h" #include "test_util.h" @@ -483,3 +487,55 @@ char *sys_get_cur_clocksource(void) return clk_name; } + +int create_tmpfs_pool_fd(const char *huge, bool noswap, size_t size) +{ + char size_str[32]; + char template[] = "/tmp/gmem_test_dir_XXXXXX"; + char *mount_dir; + int fs_fd, mnt_fd, dir_fd; + + TEST_ASSERT(size && IS_ALIGNED(size, getpagesize()), + "Pool size '0x%zx' must be positive and page-aligned", size); + + fs_fd = syscall(__NR_fsopen, "tmpfs", FSOPEN_CLOEXEC); + TEST_ASSERT(fs_fd >= 0, "fsopen failed"); + + if (noswap) + TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_SET_FLAG, + "noswap", NULL, 0), "fsconfig noswap failed"); + + if (huge) + TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_SET_STRING, + "huge", huge, 0), "fsconfig huge failed"); + + snprintf(size_str, sizeof(size_str), "%zu", size); + TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_SET_STRING, + "size", size_str, 0), "fsconfig size failed"); + + TEST_ASSERT(!syscall(__NR_fsconfig, fs_fd, FSCONFIG_CMD_CREATE, + NULL, NULL, 0), "fsconfig create failed"); + + mnt_fd = syscall(__NR_fsmount, fs_fd, FSMOUNT_CLOEXEC, 0); + TEST_ASSERT(mnt_fd > 0, "fsmount failed"); + close(fs_fd); + + mount_dir = mkdtemp(template); + TEST_ASSERT(mount_dir, "mkdtemp failed"); + + TEST_ASSERT(!syscall(__NR_move_mount, mnt_fd, "", AT_FDCWD, mount_dir, + MOVE_MOUNT_F_EMPTY_PATH), "move_mount failed"); + close(mnt_fd); + + dir_fd = open(mount_dir, O_RDONLY | O_DIRECTORY | O_CLOEXEC); + TEST_ASSERT(dir_fd >= 0, "open tmpfs mount directory failed"); + + /* + * Detach mount from namespace so removing mount_dir upon exit or + * unmount doesn't conflict, while dir_fd retains the active mount. + */ + TEST_ASSERT(!umount2(mount_dir, MNT_DETACH), "umount2 failed"); + TEST_ASSERT(!rmdir(mount_dir), "rmdir failed"); + + return dir_fd; +} diff --git a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c index e1c84df0f0596..023df9cb9d4a6 100644 --- a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c +++ b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c @@ -20,12 +20,30 @@ FIXTURE(gmem_conversions) { struct kvm_vcpu *vcpu; int gmem_fd; + int resource_fd; /* HVA of the first byte of the memory mmap()-ed from gmem_fd. */ char *mem; }; typedef FIXTURE_DATA(gmem_conversions) test_data_t; +FIXTURE_VARIANT(gmem_conversions) { + int (*create_resource)(size_t size); +}; + +FIXTURE_VARIANT_ADD(gmem_conversions, native) { + .create_resource = NULL, +}; + +static int create_tmpfs_resource(size_t size) +{ + return create_tmpfs_pool_fd("never", true, size); +} + +FIXTURE_VARIANT_ADD(gmem_conversions, tmpfs) { + .create_resource = create_tmpfs_resource, +}; + FIXTURE_SETUP(gmem_conversions) { } static size_t page_size; @@ -37,8 +55,9 @@ static void guest_do_rmw(void); * Defer setup until the individual test is invoked so that tests can specify * the number of pages and flags for the guest_memfd instance. */ -static void gmem_conversions_do_setup(test_data_t *t, int nr_pages, - int gmem_flags) +static void gmem_conversions_do_setup(test_data_t *t, + const FIXTURE_VARIANT(gmem_conversions) * variant, + int nr_pages, int gmem_flags) { const struct vm_shape shape = { .mode = VM_MODE_DEFAULT, @@ -50,12 +69,27 @@ static void gmem_conversions_do_setup(test_data_t *t, int nr_pages, */ const gpa_t gpa = SZ_4G; const u32 slot = 1; + size_t size = nr_pages * page_size; struct kvm_vm *vm; + int gmem_fd = -1; vm = __vm_create_shape_with_one_vcpu(shape, &t->vcpu, nr_pages, guest_do_rmw); + t->resource_fd = -1; + + if (variant->create_resource) { + uint64_t flags = gmem_flags | GUEST_MEMFD_FLAG_USE_RESOURCE; + + t->resource_fd = variant->create_resource(size); + TEST_ASSERT(t->resource_fd >= 0, "Failed to create backing resource"); + + gmem_fd = __vm_create_guest_memfd_resource(vm, size, flags, + t->resource_fd); + TEST_ASSERT(gmem_fd >= 0, "Failed to create guest_memfd with resource"); + } + vm_mem_add(vm, VM_MEM_SRC_SHMEM, gpa, slot, nr_pages, - KVM_MEM_GUEST_MEMFD, -1, 0, gmem_flags); + KVM_MEM_GUEST_MEMFD, gmem_fd, 0, gmem_flags); t->gmem_fd = kvm_slot_to_fd(vm, slot); t->mem = addr_gpa2hva(vm, gpa); @@ -68,6 +102,11 @@ static void gmem_conversions_do_teardown(test_data_t *t) if (!t->vcpu) return; + if (t->resource_fd >= 0) { + close(t->resource_fd); + t->resource_fd = -1; + } + /* No need to close gmem_fd, it's owned by the VM structure. */ kvm_vm_free(t->vcpu->vm); t->vcpu = NULL; @@ -91,7 +130,7 @@ TEST_F(gmem_conversions, test) \ { \ const int nr = (__nr_pages); \ \ - gmem_conversions_do_setup(self, nr, flags); \ + gmem_conversions_do_setup(self, variant, nr, flags); \ __gmem_conversions_##test(self, nr); \ } \ static void __gmem_conversions_##test(test_data_t *t, int nr_pages) \ @@ -127,7 +166,7 @@ TEST_F(gmem_conversions, test) \ int i; \ \ for (i = 0; i < nr; ++i) { \ - gmem_conversions_do_setup(self, nr, flags); \ + gmem_conversions_do_setup(self, variant, nr, flags); \ __gmem_conversions_multipage_##test(self, nr, i); \ gmem_conversions_do_teardown(self); \ } \ -- 2.56.0.455.g6c5a503b38-goog