| Message ID | 20210519200339.829146-8-axelrasmussen@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: selftests: exercise userfaultfd minor faults | expand |
On Wed, May 19, 2021 at 1:04 PM Axel Rasmussen <axelrasmussen@google.com> wrote: > > This lets us run the demand paging test on top of a shmem-backed area. > In follow-up commits, we'll 1) leverage this new capability to create an > alias mapping, and then 2) use the alias mapping to exercise UFFD minor > faults. > > Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> > --- > tools/testing/selftests/kvm/include/test_util.h | 1 + > tools/testing/selftests/kvm/lib/kvm_util.c | 15 +++++++++++++++ > tools/testing/selftests/kvm/lib/test_util.c | 5 +++++ > 3 files changed, 21 insertions(+) > > diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h > index fade3130eb01..7377f00469ef 100644 > --- a/tools/testing/selftests/kvm/include/test_util.h > +++ b/tools/testing/selftests/kvm/include/test_util.h > @@ -84,6 +84,7 @@ enum vm_mem_backing_src_type { > VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB, > VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB, > VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, > + VM_MEM_SRC_SHMEM, > NUM_SRC_TYPES, > }; > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > index bc405785ac8b..e4a8d0c43c5e 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -757,6 +757,21 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, > if (alignment > 1) > region->mmap_size += alignment; > > + region->fd = -1; Ah I guess this is the corresponding change from the previous patch. > + if (src_type == VM_MEM_SRC_SHMEM) { > + region->fd = memfd_create("kvm_selftest", MFD_CLOEXEC); > + TEST_ASSERT(region->fd != -1, > + "memfd_create failed, errno: %i", errno); > + > + ret = ftruncate(region->fd, region->mmap_size); > + TEST_ASSERT(ret == 0, "ftruncate failed, errno: %i", errno); > + > + ret = fallocate(region->fd, > + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0, > + region->mmap_size); > + TEST_ASSERT(ret == 0, "fallocate failed, errno: %i", errno); > + } > + > region->mmap_start = mmap(NULL, region->mmap_size, > PROT_READ | PROT_WRITE, > vm_mem_backing_src_alias(src_type)->flag, > diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c > index 06ddde068736..c7a265da5090 100644 > --- a/tools/testing/selftests/kvm/lib/test_util.c > +++ b/tools/testing/selftests/kvm/lib/test_util.c > @@ -236,6 +236,10 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i) > .name = "anonymous_hugetlb_16gb", > .flag = anon_huge_flags | MAP_HUGE_16GB, > }, > + [VM_MEM_SRC_SHMEM] = { > + .name = "shmem", > + .flag = MAP_SHARED, > + }, > }; > _Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES, > "Missing new backing src types?"); > @@ -253,6 +257,7 @@ size_t get_backing_src_pagesz(uint32_t i) > > switch (i) { > case VM_MEM_SRC_ANONYMOUS: > + case VM_MEM_SRC_SHMEM: > return getpagesize(); > case VM_MEM_SRC_ANONYMOUS_THP: > return get_trans_hugepagesz(); > -- > 2.31.1.751.gd2f1c929bd-goog >
diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index fade3130eb01..7377f00469ef 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -84,6 +84,7 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB, VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB, VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, + VM_MEM_SRC_SHMEM, NUM_SRC_TYPES, }; diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index bc405785ac8b..e4a8d0c43c5e 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -757,6 +757,21 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, if (alignment > 1) region->mmap_size += alignment; + region->fd = -1; + if (src_type == VM_MEM_SRC_SHMEM) { + region->fd = memfd_create("kvm_selftest", MFD_CLOEXEC); + TEST_ASSERT(region->fd != -1, + "memfd_create failed, errno: %i", errno); + + ret = ftruncate(region->fd, region->mmap_size); + TEST_ASSERT(ret == 0, "ftruncate failed, errno: %i", errno); + + ret = fallocate(region->fd, + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0, + region->mmap_size); + TEST_ASSERT(ret == 0, "fallocate failed, errno: %i", errno); + } + region->mmap_start = mmap(NULL, region->mmap_size, PROT_READ | PROT_WRITE, vm_mem_backing_src_alias(src_type)->flag, diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index 06ddde068736..c7a265da5090 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -236,6 +236,10 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i) .name = "anonymous_hugetlb_16gb", .flag = anon_huge_flags | MAP_HUGE_16GB, }, + [VM_MEM_SRC_SHMEM] = { + .name = "shmem", + .flag = MAP_SHARED, + }, }; _Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES, "Missing new backing src types?"); @@ -253,6 +257,7 @@ size_t get_backing_src_pagesz(uint32_t i) switch (i) { case VM_MEM_SRC_ANONYMOUS: + case VM_MEM_SRC_SHMEM: return getpagesize(); case VM_MEM_SRC_ANONYMOUS_THP: return get_trans_hugepagesz();
This lets us run the demand paging test on top of a shmem-backed area. In follow-up commits, we'll 1) leverage this new capability to create an alias mapping, and then 2) use the alias mapping to exercise UFFD minor faults. Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> --- tools/testing/selftests/kvm/include/test_util.h | 1 + tools/testing/selftests/kvm/lib/kvm_util.c | 15 +++++++++++++++ tools/testing/selftests/kvm/lib/test_util.c | 5 +++++ 3 files changed, 21 insertions(+)