From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE6F030C632; Sat, 26 Sep 2026 00:50:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790383852; cv=none; b=iLMsU9R/Vk9V4o7tVwQiGM+yUy3aeHm0Zd82gh5dY6WYjj7lsILqOD7L+Gov4DIB5XypGuKl+ouJr4HIPY692A0RjT8UWtygXiL1z/MGxRQSy7V1RYXR79O6Qf6T7SLTmAiy00HxIE+Lo9LQCg3+WE9Up/m6+NQrNAbJSKIM+E8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790383852; c=relaxed/simple; bh=mZ6OpaKM8VSu2SUTDptmmvQXAdF/0DN8J0W5GQhjVxA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qiktlNRLEwrnvNwTXRQrosTzw8aAFMkCm/LJXyRIYjkjabM0uCJ8lWy6YQC0VA9BbypM1xWLzDPErOyrW0VAnHC9wm81o2wH74Te5hV1ajfzFFKwAScKpR23Of+ax3I88y7CFIZRfgV6BRvBB3coCVsA+j9vzT3EvsWRUNx1sw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UspMjIxQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UspMjIxQ" Received: by smtp.kernel.org (Postfix) with ESMTPS id B91C7C2BD04; Sat, 26 Sep 2026 00:50:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1790383851; bh=mZ6OpaKM8VSu2SUTDptmmvQXAdF/0DN8J0W5GQhjVxA=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=UspMjIxQEFvLsiPa9D9JSrei2wJz1ci0gFONIhtAqb67tNFtAT5mLgMCFE/dSH/BB ZOmZDz/RyUGjmGAitUGHv0I22Jp68jtWVc/gVDn+5ZWrpcP/kP8gYBxkt9HSTo6mFj PsFMRlr2JTrPguxNGQD9PDc+PJWCKaMcs75jihPYuvTygWEMfpJZUqQSbtIF0Aofkj DZ6EFz45igxPuiqL0zsK7RA9FaxomxQZRG5Ceis+7cwuatYA2KleYQ4wBm3Bz/wkw+ 9L+HNygzTF8LZY3DfKoCFwESTGhlcCE0g2W/HJCeOnGJxd8ZiytYlmIwNZ0pfzg31r Uy8ALX2tguiHg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id A14E9C9830E; Sat, 26 Sep 2026 00:50:51 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Fri, 25 Sep 2026 17:50:54 -0700 Subject: [PATCH RFC 07/17] KVM: selftests: Test rejection of unsupported filesystem for resource_fd Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260925-gmem-tmpfs-backend-v1-7-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; a=ed25519-sha256; t=1790383850; l=1760; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=c84B6n44NVtK2sHukMLB5KU4J3iKw7GkSZw3Puqe1NE=; b=mcUInbCP1l8RBE0LpSG40yF7SVS0NuEdAcubDuydYZGl6HTZiLO6aKz+MNMBBt9W88whJp98Y rYy1PfGCdV/CUbRH++lB6miMh/H7JzZ5SsHOreuZCnL0q9f+cNQcqzO 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 From: Ackerley Tng Add test coverage verifying that passing a directory file descriptor from an unsupported filesystem without provider operations as a resource file fails with EOPNOTSUPP. Signed-off-by: Ackerley Tng --- tools/testing/selftests/kvm/guest_memfd_test.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index 84b958b9ef715..31bc74c4c26bd 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -436,6 +436,27 @@ static void test_resource_fd_invalid(struct kvm_vm *vm) TEST_ASSERT_EQ(errno, EBADF); } +static void test_resource_fd_unsupported_fs(struct kvm_vm *vm) +{ + int fd, file_fd; + + /* + * Passing an FD from an unsupported filesystem without provider ops + * (e.g. the /proc mount root directory) is rejected by KVM with + * EOPNOTSUPP. + */ + file_fd = open("/proc", O_DIRECTORY | O_RDONLY); + TEST_ASSERT(file_fd >= 0, "open /proc failed"); + + fd = __vm_create_guest_memfd_resource(vm, page_size, + GUEST_MEMFD_FLAG_USE_RESOURCE, + file_fd); + TEST_ASSERT(fd < 0, "guest_memfd with /proc fd should fail"); + TEST_ASSERT_EQ(errno, EOPNOTSUPP); + + close(file_fd); +} + #define ____gmem_test(__test, __vm, __flags, __gmem_size, args...) \ do { \ int fd = vm_create_guest_memfd(__vm, __gmem_size, __flags); \ @@ -495,6 +516,7 @@ static void test_guest_memfd(unsigned long vm_type) test_guest_memfd_flags(vm); test_resource_fd_invalid(vm); + test_resource_fd_unsupported_fs(vm); __test_guest_memfd(vm, 0); -- 2.56.0.rc1.315.gc6ed9934b7-goog