From nobody Fri Oct 3 16:41:15 2025 Received: from fra-out-004.esa.eu-central-1.outbound.mail-perimeter.amazon.com (fra-out-004.esa.eu-central-1.outbound.mail-perimeter.amazon.com [3.74.81.189]) (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 BD6B8221557; Thu, 28 Aug 2025 15:31:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=3.74.81.189 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756395085; cv=none; b=HPLyahBU2L58dEUtx6jKrYs42q9KFTSApU0btYb9pHE8r+pn1dmlTiyTykH7Qr/isC8Yn2s/XVZ+Nd1g3fdmHyNgYvSf2UF8FPHaP2q/hBqCvgs7a07vfNDB39FsNnnTZjh9eAn6Oul06Yxm6gHa92tHweEwPMUcjHRMGmmU1W8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756395085; c=relaxed/simple; bh=mk7b2YyAsivRkDVPxo2FPF/ODspXCEyaZ6Ip/VG95w8=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=C/V+3v+k7Z/778BLTdYkSgs8i+wuaMuifXShSZEnQ+SnGgA7zHxissDjTCp7Xm6xCqjFXO1R/Y7qiLEE9mqwdW/jnzxgmdu+FyjAca+NPAxYcLTAKyoagTu/kZEoMMr0vG1unUQSPkwAyHwAAwpzbDUHVx3wKxonT4syRM0hKSI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.co.uk; spf=pass smtp.mailfrom=amazon.co.uk; dkim=pass (2048-bit key) header.d=amazon.co.uk header.i=@amazon.co.uk header.b=fDTlmxfA; arc=none smtp.client-ip=3.74.81.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.co.uk header.i=@amazon.co.uk header.b="fDTlmxfA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.uk; i=@amazon.co.uk; q=dns/txt; s=amazoncorp2; t=1756395083; x=1787931083; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=V5me1vbEPjC3lLIXGRdLlLGlsFqu+EM7eB3QDsegrgE=; b=fDTlmxfARDA3jzhTnVBIgNK8V7gIMuqtwWUqqSUIB91/ggZAk8DuKC7l ZdEwdHcbY7nri5/Wrn9ZpvlerVGWlb9/SOcbSL0b8QQsvPFhlkRYUebpN lkAXXWAOH+iFP6WkN6UxbKMdzdzCxQwahEMvHjLxQLKEz79CN6MmGb8cA AUUOE69gK3Lis1muIPb4PIowWoU3+afhH+3KLHPYI6VDFRzDDuC5J1ntm MEKpwAXJZ9G3/KBoFCcpg88wYwtnoNLQUT2FWJcxz6vmDU/sdgOxBx+QD aT8gHg1Zyg4fTtHiSzaZop0jnSfTpnQDUwmKLGU6PV9lPlhYi/z3Iv8GM w==; X-CSE-ConnectionGUID: I2OtGiczTv6U+aeUYpDu2g== X-CSE-MsgGUID: BA0NUChcRRyEMf7aQczCTg== X-IronPort-AV: E=Sophos;i="6.18,214,1751241600"; d="scan'208";a="1327209" Received: from ip-10-6-11-83.eu-central-1.compute.internal (HELO smtpout.naws.eu-central-1.prod.farcaster.email.amazon.dev) ([10.6.11.83]) by internal-fra-out-004.esa.eu-central-1.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Aug 2025 15:31:13 +0000 Received: from EX19MTAEUB002.ant.amazon.com [54.240.197.232:17221] by smtpin.naws.eu-central-1.prod.farcaster.email.amazon.dev [10.0.16.219:2525] with esmtp (Farcaster) id 2368e651-18b1-4fbf-946e-1f80a29a505a; Thu, 28 Aug 2025 15:31:13 +0000 (UTC) X-Farcaster-Flow-ID: 2368e651-18b1-4fbf-946e-1f80a29a505a Received: from EX19D022EUC003.ant.amazon.com (10.252.51.167) by EX19MTAEUB002.ant.amazon.com (10.252.51.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.17; Thu, 28 Aug 2025 15:31:13 +0000 Received: from EX19D022EUC002.ant.amazon.com (10.252.51.137) by EX19D022EUC003.ant.amazon.com (10.252.51.167) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.17; Thu, 28 Aug 2025 15:31:12 +0000 Received: from EX19D022EUC002.ant.amazon.com ([fe80::bd:307b:4d3a:7d80]) by EX19D022EUC002.ant.amazon.com ([fe80::bd:307b:4d3a:7d80%3]) with mapi id 15.02.2562.017; Thu, 28 Aug 2025 15:31:12 +0000 From: "Kalyazin, Nikita" To: "pbonzini@redhat.com" , "shuah@kernel.org" CC: "kvm@vger.kernel.org" , "linux-kselftest@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "michael.day@amd.com" , "david@redhat.com" , "jthoughton@google.com" , "Roy, Patrick" , "Thomson, Jack" , "Manwaring, Derek" , "Cali, Marco" , "Kalyazin, Nikita" Subject: [PATCH v4 2/2] KVM: selftests: update guest_memfd write tests Thread-Topic: [PATCH v4 2/2] KVM: selftests: update guest_memfd write tests Thread-Index: AQHcGDDJcxHhkxTsa0ilibpNOQvawQ== Date: Thu, 28 Aug 2025 15:31:12 +0000 Message-ID: <20250828153049.3922-3-kalyazin@amazon.com> References: <20250828153049.3922-1-kalyazin@amazon.com> In-Reply-To: <20250828153049.3922-1-kalyazin@amazon.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Transfer-Encoding: quoted-printable 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" This is to reflect that the write syscall is now implemented for guest_memfd. Signed-off-by: Nikita Kalyazin --- .../testing/selftests/kvm/guest_memfd_test.c | 85 +++++++++++++++++-- 1 file changed, 79 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing= /selftests/kvm/guest_memfd_test.c index b3ca6737f304..7217a3232055 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -24,18 +24,90 @@ #include "test_util.h" #include "ucall_common.h" =20 -static void test_file_read_write(int fd) +static void test_file_read(int fd) { char buf[64]; =20 TEST_ASSERT(read(fd, buf, sizeof(buf)) < 0, "read on a guest_mem fd should fail"); - TEST_ASSERT(write(fd, buf, sizeof(buf)) < 0, - "write on a guest_mem fd should fail"); TEST_ASSERT(pread(fd, buf, sizeof(buf), 0) < 0, "pread on a guest_mem fd should fail"); - TEST_ASSERT(pwrite(fd, buf, sizeof(buf), 0) < 0, - "pwrite on a guest_mem fd should fail"); +} + +static void test_file_write(int fd, size_t total_size) +{ + size_t page_size =3D getpagesize(); + void *buf =3D NULL; + int ret; + + ret =3D posix_memalign(&buf, page_size, total_size); + TEST_ASSERT_EQ(ret, 0); + + /* Check arguments correctness checks work as expected */ + + ret =3D pwrite(fd, buf, page_size - 1, 0); + TEST_ASSERT(ret =3D=3D -1, "write unaligned count on a guest_mem fd shoul= d fail"); + TEST_ASSERT_EQ(errno, EINVAL); + + ret =3D pwrite(fd, buf, page_size, 1); + TEST_ASSERT(ret =3D=3D -1, "write unaligned offset on a guest_mem fd shou= ld fail"); + TEST_ASSERT_EQ(errno, EINVAL); + + ret =3D pwrite(fd, buf, page_size, total_size); + TEST_ASSERT(ret =3D=3D -1, "writing past the file size on a guest_mem fd = should fail"); + TEST_ASSERT_EQ(errno, EINVAL); + + ret =3D pwrite(fd, NULL, page_size, 0); + TEST_ASSERT(ret =3D=3D -1, "supplying a NULL buffer when writing a guest_= mem fd should fail"); + TEST_ASSERT_EQ(errno, EFAULT); + + /* Check double population is not allowed */ + + ret =3D pwrite(fd, buf, page_size, 0); + TEST_ASSERT(ret =3D=3D page_size, "page-aligned write on a guest_mem fd s= hould succeed"); + + ret =3D pwrite(fd, buf, page_size, 0); + TEST_ASSERT(ret =3D=3D -1, "write on already populated guest_mem fd shoul= d fail"); + TEST_ASSERT_EQ(errno, ENOSPC); + + ret =3D fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, page= _size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) should succeed"); + + /* Check population is allowed again after punching a hole */ + + ret =3D pwrite(fd, buf, page_size, 0); + TEST_ASSERT(ret =3D=3D page_size, "page-aligned write on a punched guest_= mem fd should succeed"); + + ret =3D fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, page= _size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) should succeed"); + + /* Check population of already allocated memory is allowed */ + + ret =3D fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, page_size); + TEST_ASSERT(!ret, "fallocate with aligned offset and size should succeed"= ); + + ret =3D pwrite(fd, buf, page_size, 0); + TEST_ASSERT(ret =3D=3D page_size, "write on a preallocated guest_mem fd s= hould succeed"); + + ret =3D fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, page= _size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) should succeed"); + + /* Check population works until an already populated page is encountered = */ + + ret =3D pwrite(fd, buf, total_size, 0); + TEST_ASSERT(ret =3D=3D total_size, "page-aligned write on a guest_mem fd = should succeed"); + + ret =3D fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, page= _size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) should succeed"); + + ret =3D pwrite(fd, buf, total_size, 0); + TEST_ASSERT(ret =3D=3D page_size, "write on a guest_mem fd should not ove= rwrite data"); + + ret =3D fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, tota= l_size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) should succeed"); + + + free(buf); } =20 static void test_mmap_supported(int fd, size_t page_size, size_t total_siz= e) @@ -281,7 +353,8 @@ static void test_guest_memfd(unsigned long vm_type) =20 fd =3D vm_create_guest_memfd(vm, total_size, flags); =20 - test_file_read_write(fd); + test_file_read(fd); + test_file_write(fd, total_size); =20 if (flags & GUEST_MEMFD_FLAG_MMAP) { test_mmap_supported(fd, page_size, total_size); --=20 2.50.1