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charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260925-gmem-tmpfs-backend-v1-13-d36159822d18@google.com> References: <20260925-gmem-tmpfs-backend-v1-0-d36159822d18@google.com> In-Reply-To: <20260925-gmem-tmpfs-backend-v1-0-d36159822d18@google.com> To: Hugh Dickins , Baolin Wang , Andrew Morton , Sean Christopherson , Paolo Bonzini , David Hildenbrand , Jonathan Corbet , Shuah Khan , Randy Dunlap , Shuah Khan , vannapurve@google.com, erdemaktas@google.com, jxgao@google.com, rientjes@google.com, fvdl@google.com, jthoughton@google.com, tarunsahu@google.com, pratyush@kernel.org, fuad.tabba@linux.dev, Gregory Price , David Woodhouse , yan.y.zhao@intel.com, michael.roth@amd.com, suzuki.poulose@arm.com, Christian Brauner , Jason Gunthorpe , Nicolin Chen , Xu Yilun , aik@amd.com, aneesh.kumar@kernel.org, Vlastimil Babka Cc: kernel-team@android.com, kernel-team@meta.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Ackerley Tng X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; 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Signed-off-by: Ackerley Tng --- tools/testing/selftests/kvm/guest_memfd_test.c | 36 ++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index 94ef64474f2a0..81311be059923 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -543,6 +543,41 @@ static void test_resource_fd_tmpfs_huge(struct kvm_vm *vm) close(pool_fd); } +static void test_resource_fd_tmpfs_shared_pool(struct kvm_vm *vm) +{ + int pool_fd, fd1, fd2; + struct stat st1, st2; + + pool_fd = create_tmpfs_pool_fd("never", true, page_size * 2); + if (pool_fd < 0) + TEST_REQUIRE(false); + + fd1 = vm_create_guest_memfd_resource(vm, page_size, + GUEST_MEMFD_FLAG_USE_RESOURCE, + pool_fd); + + fd2 = vm_create_guest_memfd_resource(vm, page_size * 2, + GUEST_MEMFD_FLAG_USE_RESOURCE, + pool_fd); + + TEST_ASSERT(!fstat(fd1, &st1), "fstat on fd1 should succeed"); + TEST_ASSERT(st1.st_size == page_size, + "fd1 st_size (%lu) should match requested size (%lu)", + st1.st_size, page_size); + + TEST_ASSERT(!fstat(fd2, &st2), "fstat on fd2 should succeed"); + TEST_ASSERT(st2.st_size == page_size * 2, + "fd2 st_size (%lu) should match requested size (%lu)", + st2.st_size, page_size * 2); + + TEST_ASSERT(st1.st_ino != st2.st_ino, + "different guest_memfd instances should have distinct inodes"); + + close(fd2); + close(fd1); + close(pool_fd); +} + enum gmem_pool_type { GMEM_POOL_NONE, GMEM_POOL_FSMOUNT, @@ -673,6 +708,7 @@ static void test_guest_memfd(unsigned long vm_type) test_resource_fd_tmpfs_file(vm); test_resource_fd_tmpfs_swap(vm); test_resource_fd_tmpfs_huge(vm); + test_resource_fd_tmpfs_shared_pool(vm); __test_guest_memfd(vm, 0, GMEM_POOL_NONE); __test_guest_memfd(vm, GUEST_MEMFD_FLAG_USE_RESOURCE, GMEM_POOL_FSMOUNT); -- 2.56.0.rc1.315.gc6ed9934b7-goog