From patchwork Sun Nov 5 16:30:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13446015 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C18DCC4332F for ; Sun, 5 Nov 2023 16:38:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230356AbjKEQig (ORCPT ); Sun, 5 Nov 2023 11:38:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230477AbjKEQiS (ORCPT ); Sun, 5 Nov 2023 11:38:18 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EF0C1B2 for ; Sun, 5 Nov 2023 08:35:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699202103; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=spqhuF0PZGaMSdHDZ1KRxocAKbjvl7sJJnsJWiVNP2k=; b=DsEzRa0FhUR3FE9kA4gbmfBUiJAKIoyC5lhBD6TGp7miv268YaiGQDx9tMk1o4Bmg4N3T0 kEj1q9xzFI0tVeGSx8HZY5CoOsu7RJit2nPTk9WlvSnnOBLsSIzGWZgV/3G8pJvgFUEsQ3 AKYJEQGUs2aTHLM3ltM6fYey9XNffOA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-591-9xnWxafYO26IbHoplvKORA-1; Sun, 05 Nov 2023 11:34:58 -0500 X-MC-Unique: 9xnWxafYO26IbHoplvKORA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 39603810FC1; Sun, 5 Nov 2023 16:34:56 +0000 (UTC) Received: from avogadro.redhat.com (unknown [10.39.192.93]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5ED902166B26; Sun, 5 Nov 2023 16:34:48 +0000 (UTC) From: Paolo Bonzini To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Sean Christopherson , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Xu Yilun , Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , David Matlack , Yu Zhang , Isaku Yamahata , =?utf-8?q?Micka=C3=ABl_Sala?= =?utf-8?q?=C3=BCn?= , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A. Shutemov" Subject: [PATCH 32/34] KVM: selftests: Add basic selftest for guest_memfd() Date: Sun, 5 Nov 2023 17:30:35 +0100 Message-ID: <20231105163040.14904-33-pbonzini@redhat.com> In-Reply-To: <20231105163040.14904-1-pbonzini@redhat.com> References: <20231105163040.14904-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Chao Peng Add a selftest to verify the basic functionality of guest_memfd(): + file descriptor created with the guest_memfd() ioctl does not allow read/write/mmap operations + file size and block size as returned from fstat are as expected + fallocate on the fd checks that offset/length on fallocate(FALLOC_FL_PUNCH_HOLE) should be page aligned + invalid inputs (misaligned size, invalid flags) are rejected + file size and inode are unique (the innocuous-sounding anon_inode_getfile() backs all files with a single inode...) Signed-off-by: Chao Peng Co-developed-by: Ackerley Tng Signed-off-by: Ackerley Tng Co-developed-by: Paolo Bonzini Signed-off-by: Paolo Bonzini Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Message-Id: <20231027182217.3615211-35-seanjc@google.com> Signed-off-by: Paolo Bonzini Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba --- tools/testing/selftests/kvm/Makefile | 1 + .../testing/selftests/kvm/guest_memfd_test.c | 206 ++++++++++++++++++ 2 files changed, 207 insertions(+) create mode 100644 tools/testing/selftests/kvm/guest_memfd_test.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index ecdea5e7afa8..fd3b30a4ca7b 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -134,6 +134,7 @@ TEST_GEN_PROGS_x86_64 += access_tracking_perf_test TEST_GEN_PROGS_x86_64 += demand_paging_test TEST_GEN_PROGS_x86_64 += dirty_log_test TEST_GEN_PROGS_x86_64 += dirty_log_perf_test +TEST_GEN_PROGS_x86_64 += guest_memfd_test TEST_GEN_PROGS_x86_64 += guest_print_test TEST_GEN_PROGS_x86_64 += hardware_disable_test TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c new file mode 100644 index 000000000000..ea0ae7e25330 --- /dev/null +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright Intel Corporation, 2023 + * + * Author: Chao Peng + */ + +#define _GNU_SOURCE +#include "test_util.h" +#include "kvm_util_base.h" +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static void test_file_read_write(int fd) +{ + char buf[64]; + + 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_mmap(int fd, size_t page_size) +{ + char *mem; + + mem = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT_EQ(mem, MAP_FAILED); +} + +static void test_file_size(int fd, size_t page_size, size_t total_size) +{ + struct stat sb; + int ret; + + ret = fstat(fd, &sb); + TEST_ASSERT(!ret, "fstat should succeed"); + TEST_ASSERT_EQ(sb.st_size, total_size); + TEST_ASSERT_EQ(sb.st_blksize, page_size); +} + +static void test_fallocate(int fd, size_t page_size, size_t total_size) +{ + int ret; + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, total_size); + TEST_ASSERT(!ret, "fallocate with aligned offset and size should succeed"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + page_size - 1, page_size); + TEST_ASSERT(ret, "fallocate with unaligned offset should fail"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, total_size, page_size); + TEST_ASSERT(ret, "fallocate beginning at total_size should fail"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, total_size + page_size, page_size); + TEST_ASSERT(ret, "fallocate beginning after total_size should fail"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + total_size, page_size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) at total_size should succeed"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + total_size + page_size, page_size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) after total_size should succeed"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + page_size, page_size - 1); + TEST_ASSERT(ret, "fallocate with unaligned size should fail"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + page_size, page_size); + TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) with aligned offset and size should succeed"); + + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, page_size, page_size); + TEST_ASSERT(!ret, "fallocate to restore punched hole should succeed"); +} + +static void test_invalid_punch_hole(int fd, size_t page_size, size_t total_size) +{ + struct { + off_t offset; + off_t len; + } testcases[] = { + {0, 1}, + {0, page_size - 1}, + {0, page_size + 1}, + + {1, 1}, + {1, page_size - 1}, + {1, page_size}, + {1, page_size + 1}, + + {page_size, 1}, + {page_size, page_size - 1}, + {page_size, page_size + 1}, + }; + int ret, i; + + for (i = 0; i < ARRAY_SIZE(testcases); i++) { + ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + testcases[i].offset, testcases[i].len); + TEST_ASSERT(ret == -1 && errno == EINVAL, + "PUNCH_HOLE with !PAGE_SIZE offset (%lx) and/or length (%lx) should fail", + testcases[i].offset, testcases[i].len); + } +} + +static void test_create_guest_memfd_invalid(struct kvm_vm *vm) +{ + size_t page_size = getpagesize(); + uint64_t flag; + size_t size; + int fd; + + for (size = 1; size < page_size; size++) { + fd = __vm_create_guest_memfd(vm, size, 0); + TEST_ASSERT(fd == -1 && errno == EINVAL, + "guest_memfd() with non-page-aligned page size '0x%lx' should fail with EINVAL", + size); + } + + for (flag = 1; flag; flag <<= 1) { + uint64_t bit; + + fd = __vm_create_guest_memfd(vm, page_size, flag); + TEST_ASSERT(fd == -1 && errno == EINVAL, + "guest_memfd() with flag '0x%lx' should fail with EINVAL", + flag); + + for_each_set_bit(bit, &valid_flags, 64) { + fd = __vm_create_guest_memfd(vm, page_size, flag | BIT_ULL(bit)); + TEST_ASSERT(fd == -1 && errno == EINVAL, + "guest_memfd() with flags '0x%llx' should fail with EINVAL", + flag | BIT_ULL(bit)); + } + } +} + +static void test_create_guest_memfd_multiple(struct kvm_vm *vm) +{ + int fd1, fd2, ret; + struct stat st1, st2; + + fd1 = __vm_create_guest_memfd(vm, 4096, 0); + TEST_ASSERT(fd1 != -1, "memfd creation should succeed"); + + ret = fstat(fd1, &st1); + TEST_ASSERT(ret != -1, "memfd fstat should succeed"); + TEST_ASSERT(st1.st_size == 4096, "memfd st_size should match requested size"); + + fd2 = __vm_create_guest_memfd(vm, 8192, 0); + TEST_ASSERT(fd2 != -1, "memfd creation should succeed"); + + ret = fstat(fd2, &st2); + TEST_ASSERT(ret != -1, "memfd fstat should succeed"); + TEST_ASSERT(st2.st_size == 8192, "second memfd st_size should match requested size"); + + ret = fstat(fd1, &st1); + TEST_ASSERT(ret != -1, "memfd fstat should succeed"); + TEST_ASSERT(st1.st_size == 4096, "first memfd st_size should still match requested size"); + TEST_ASSERT(st1.st_ino != st2.st_ino, "different memfd should have different inode numbers"); +} + +int main(int argc, char *argv[]) +{ + size_t page_size; + size_t total_size; + int fd; + struct kvm_vm *vm; + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD)); + + page_size = getpagesize(); + total_size = page_size * 4; + + vm = vm_create_barebones(); + + test_create_guest_memfd_invalid(vm); + test_create_guest_memfd_multiple(vm); + + fd = vm_create_guest_memfd(vm, total_size, 0); + + test_file_read_write(fd); + test_mmap(fd, page_size); + test_file_size(fd, page_size, total_size); + test_fallocate(fd, page_size, total_size); + test_invalid_punch_hole(fd, page_size, total_size); + + close(fd); +}