From: Ackerley Tng via B4 Relay <devnull+ackerleytng.google.com@kernel.org>
To: Hugh Dickins <hughd@google.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Andrew Morton <akpm@linux-foundation.org>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
David Hildenbrand <david@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
Randy Dunlap <rdunlap@infradead.org>,
Shuah Khan <shuah@kernel.org>,
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 <gourry@gourry.net>,
David Woodhouse <dwmw2@infradead.org>,
yan.y.zhao@intel.com, michael.roth@amd.com,
suzuki.poulose@arm.com, Christian Brauner <brauner@kernel.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
Nicolin Chen <nicolinc@nvidia.com>,
Xu Yilun <yilun.xu@linux.intel.com>,
aik@amd.com, aneesh.kumar@kernel.org,
Vlastimil Babka <vbabka@kernel.org>
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 <ackerleytng@google.com>
Subject: [PATCH RFC 14/17] KVM: selftests: Test memory allocation against shared tmpfs resource pool
Date: Fri, 25 Sep 2026 17:51:01 -0700 [thread overview]
Message-ID: <20260925-gmem-tmpfs-backend-v1-14-d36159822d18@google.com> (raw)
In-Reply-To: <20260925-gmem-tmpfs-backend-v1-0-d36159822d18@google.com>
From: Ackerley Tng <ackerleytng@google.com>
Verify that allocating folios in multiple guest_memfd instances sharing
the same tmpfs resource pool consumes blocks from the underlying pool as
reported by filesystem statistics.
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
tools/testing/selftests/kvm/guest_memfd_test.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index 81311be059923..4610eeab39be6 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -19,6 +19,7 @@
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/statvfs.h>
#include "kvm_syscalls.h"
#include "kvm_util.h"
@@ -545,7 +546,8 @@ static void test_resource_fd_tmpfs_huge(struct kvm_vm *vm)
static void test_resource_fd_tmpfs_shared_pool(struct kvm_vm *vm)
{
- int pool_fd, fd1, fd2;
+ int pool_fd, fd1, fd2, ret;
+ struct statvfs svfs;
struct stat st1, st2;
pool_fd = create_tmpfs_pool_fd("never", true, page_size * 2);
@@ -573,6 +575,18 @@ static void test_resource_fd_tmpfs_shared_pool(struct kvm_vm *vm)
TEST_ASSERT(st1.st_ino != st2.st_ino,
"different guest_memfd instances should have distinct inodes");
+ ret = fallocate(fd1, FALLOC_FL_KEEP_SIZE, 0, page_size);
+ TEST_ASSERT(!ret, "fallocate on fd1 should succeed");
+
+ TEST_ASSERT(!fstatvfs(pool_fd, &svfs), "fstatvfs on pool_fd should succeed");
+ TEST_ASSERT_EQ(svfs.f_blocks - svfs.f_bfree, 1);
+
+ ret = fallocate(fd2, FALLOC_FL_KEEP_SIZE, 0, page_size);
+ TEST_ASSERT(!ret, "fallocate on fd2 should succeed");
+
+ TEST_ASSERT(!fstatvfs(pool_fd, &svfs), "fstatvfs on pool_fd should succeed");
+ TEST_ASSERT_EQ(svfs.f_blocks - svfs.f_bfree, 2);
+
close(fd2);
close(fd1);
close(pool_fd);
--
2.56.0.rc1.315.gc6ed9934b7-goog
next prev parent reply other threads:[~2026-09-26 0:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-26 0:50 [PATCH RFC 00/17] Allow guest_memfd to be created using a resource (pool) fd Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 01/17] mm: shmem: Implement guest_memfd provider operations for tmpfs Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 02/17] KVM: guest_memfd: Support provider folio allocation Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 03/17] KVM: guest_memfd: Support provider folio invalidation Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 04/17] KVM: guest_memfd: Add helper to attach resource provider file Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 05/17] KVM: selftests: Add helper to create guest_memfd with a resource file Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 06/17] KVM: selftests: Test negative validation of resource_fd argument Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 07/17] KVM: selftests: Test rejection of unsupported filesystem for resource_fd Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 08/17] KVM: selftests: Test rejection of tmpfs file " Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 09/17] KVM: selftests: Test rejection of swap tmpfs mounts Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 10/17] KVM: selftests: Test rejection of hugepage " Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 11/17] KVM: selftests: Test guest_memfd with anonymous fsmount() tmpfs pool Ackerley Tng via B4 Relay
2026-09-26 0:50 ` [PATCH RFC 12/17] KVM: selftests: Test guest_memfd with mounted tmpfs root directory Ackerley Tng via B4 Relay
2026-09-26 0:51 ` [PATCH RFC 13/17] KVM: selftests: Test guest_memfd resource pool sharing across instances Ackerley Tng via B4 Relay
2026-09-26 0:51 ` Ackerley Tng via B4 Relay [this message]
2026-09-26 0:51 ` [PATCH RFC 15/17] KVM: selftests: Test that shared tmpfs resource pool size limit is respected Ackerley Tng via B4 Relay
2026-09-26 0:51 ` [PATCH RFC 16/17] KVM: selftests: Test guest execution with tmpfs-backed guest_memfd Ackerley Tng via B4 Relay
2026-09-26 0:51 ` [PATCH RFC 17/17] KVM: selftests: Document testing TODOs Ackerley Tng via B4 Relay
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