| Message ID | 20231105163040.14904-33-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: guest_memfd() and per-page attributes | expand |
Hi, On Sun, Nov 5, 2023 at 4:35 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > > From: Chao Peng <chao.p.peng@linux.intel.com> > > 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 <chao.p.peng@linux.intel.com> > Co-developed-by: Ackerley Tng <ackerleytng@google.com> > Signed-off-by: Ackerley Tng <ackerleytng@google.com> > Co-developed-by: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > Co-developed-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Sean Christopherson <seanjc@google.com> > Message-Id: <20231027182217.3615211-35-seanjc@google.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > 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 <chao.p.peng@linux.intel.com> > + */ > + > +#define _GNU_SOURCE > +#include "test_util.h" > +#include "kvm_util_base.h" > +#include <linux/bitmap.h> > +#include <linux/falloc.h> > +#include <sys/mman.h> > +#include <sys/types.h> > +#include <sys/stat.h> > + > +#include <stdlib.h> > +#include <string.h> > +#include <unistd.h> > +#include <errno.h> > +#include <stdio.h> > +#include <fcntl.h> The include ordering should be fixed. Otherwise, Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Cheers, /fuad > + > +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); > +} > -- > 2.39.1 > >
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 <chao.p.peng@linux.intel.com> + */ + +#define _GNU_SOURCE +#include "test_util.h" +#include "kvm_util_base.h" +#include <linux/bitmap.h> +#include <linux/falloc.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <stdio.h> +#include <fcntl.h> + +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); +}