| Message ID | 20210512214502.2047008-6-axelrasmussen@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/5] KVM: selftests: allow different backing memory types for demand paging | expand |
On Wed, May 12, 2021 at 2:45 PM Axel Rasmussen <axelrasmussen@google.com> wrote: > > This lets us run the demand paging test on top of a shared > hugetlbfs-backed area. The "shared" is key, as this allows us to > exercise userfaultfd minor faults on hugetlbfs. > > Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> > --- > tools/testing/selftests/kvm/demand_paging_test.c | 6 ++++-- > tools/testing/selftests/kvm/include/test_util.h | 10 ++++++++++ > tools/testing/selftests/kvm/lib/kvm_util.c | 9 +++++++-- > tools/testing/selftests/kvm/lib/test_util.c | 6 ++++++ > 4 files changed, 27 insertions(+), 4 deletions(-) > > diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c > index ff29aaea3120..32942c9e0376 100644 > --- a/tools/testing/selftests/kvm/demand_paging_test.c > +++ b/tools/testing/selftests/kvm/demand_paging_test.c > @@ -502,8 +502,10 @@ int main(int argc, char *argv[]) > } > } > > - TEST_ASSERT(p.uffd_mode != UFFDIO_REGISTER_MODE_MINOR || p.src_type == VM_MEM_SRC_SHMEM, > - "userfaultfd MINOR mode requires shared memory; pick a different -t"); > + if (p.uffd_mode == UFFDIO_REGISTER_MODE_MINOR && > + !backing_src_is_shared(p.src_type)) { > + TEST_FAIL("userfaultfd MINOR mode requires shared memory; pick a different -t"); > + } > > for_each_guest_mode(run_test, &p); > > diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h > index 7377f00469ef..852d6d2cc285 100644 > --- a/tools/testing/selftests/kvm/include/test_util.h > +++ b/tools/testing/selftests/kvm/include/test_util.h > @@ -85,9 +85,19 @@ enum vm_mem_backing_src_type { > VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB, > VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, > VM_MEM_SRC_SHMEM, > + VM_MEM_SRC_SHARED_HUGETLB, > NUM_SRC_TYPES, > }; > > +/* > + * Whether or not the given source type is shared memory (as opposed to > + * anonymous). > + */ > +static inline bool backing_src_is_shared(enum vm_mem_backing_src_type t) > +{ > + return t == VM_MEM_SRC_SHMEM || t == VM_MEM_SRC_SHARED_HUGETLB; > +} Would it make sense to check (vm_mem_backing_src_alias(t)->flag & MAP_SHARED) == MAP_SHARED instead? > + > struct vm_mem_backing_src_alias { > const char *name; > uint32_t flag; > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > index 838d58633f7e..fed02153c919 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -756,8 +756,13 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, > region->mmap_size += alignment; > > region->fd = -1; > - if (src_type == VM_MEM_SRC_SHMEM) { > - region->fd = memfd_create("kvm_selftest", MFD_CLOEXEC); > + if (backing_src_is_shared(src_type)) { > + int memfd_flags = MFD_CLOEXEC; > + > + if (src_type == VM_MEM_SRC_SHARED_HUGETLB) > + memfd_flags |= MFD_HUGETLB; > + > + region->fd = memfd_create("kvm_selftest", memfd_flags); > TEST_ASSERT(region->fd != -1, > "memfd_create failed, errno: %i", errno); > > diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c > index c7a265da5090..65fb8b43782c 100644 > --- a/tools/testing/selftests/kvm/lib/test_util.c > +++ b/tools/testing/selftests/kvm/lib/test_util.c > @@ -240,6 +240,11 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i) > .name = "shmem", > .flag = MAP_SHARED, > }, > + [VM_MEM_SRC_SHARED_HUGETLB] = { > + .name = "shared_hugetlb", > + /* No MAP_HUGETLB, we use MFD_HUGETLB instead. */ Is it worth calling out the difference between the two flags here? > + .flag = MAP_SHARED, > + }, > }; > _Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES, > "Missing new backing src types?"); > @@ -262,6 +267,7 @@ size_t get_backing_src_pagesz(uint32_t i) > case VM_MEM_SRC_ANONYMOUS_THP: > return get_trans_hugepagesz(); > case VM_MEM_SRC_ANONYMOUS_HUGETLB: > + case VM_MEM_SRC_SHARED_HUGETLB: > return get_def_hugetlb_pagesz(); > default: > return MAP_HUGE_PAGE_SIZE(flag); > -- > 2.31.1.607.g51e8a6a459-goog >
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c index ff29aaea3120..32942c9e0376 100644 --- a/tools/testing/selftests/kvm/demand_paging_test.c +++ b/tools/testing/selftests/kvm/demand_paging_test.c @@ -502,8 +502,10 @@ int main(int argc, char *argv[]) } } - TEST_ASSERT(p.uffd_mode != UFFDIO_REGISTER_MODE_MINOR || p.src_type == VM_MEM_SRC_SHMEM, - "userfaultfd MINOR mode requires shared memory; pick a different -t"); + if (p.uffd_mode == UFFDIO_REGISTER_MODE_MINOR && + !backing_src_is_shared(p.src_type)) { + TEST_FAIL("userfaultfd MINOR mode requires shared memory; pick a different -t"); + } for_each_guest_mode(run_test, &p); diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index 7377f00469ef..852d6d2cc285 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -85,9 +85,19 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB, VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, VM_MEM_SRC_SHMEM, + VM_MEM_SRC_SHARED_HUGETLB, NUM_SRC_TYPES, }; +/* + * Whether or not the given source type is shared memory (as opposed to + * anonymous). + */ +static inline bool backing_src_is_shared(enum vm_mem_backing_src_type t) +{ + return t == VM_MEM_SRC_SHMEM || t == VM_MEM_SRC_SHARED_HUGETLB; +} + struct vm_mem_backing_src_alias { const char *name; uint32_t flag; diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 838d58633f7e..fed02153c919 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -756,8 +756,13 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, region->mmap_size += alignment; region->fd = -1; - if (src_type == VM_MEM_SRC_SHMEM) { - region->fd = memfd_create("kvm_selftest", MFD_CLOEXEC); + if (backing_src_is_shared(src_type)) { + int memfd_flags = MFD_CLOEXEC; + + if (src_type == VM_MEM_SRC_SHARED_HUGETLB) + memfd_flags |= MFD_HUGETLB; + + region->fd = memfd_create("kvm_selftest", memfd_flags); TEST_ASSERT(region->fd != -1, "memfd_create failed, errno: %i", errno); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index c7a265da5090..65fb8b43782c 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -240,6 +240,11 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i) .name = "shmem", .flag = MAP_SHARED, }, + [VM_MEM_SRC_SHARED_HUGETLB] = { + .name = "shared_hugetlb", + /* No MAP_HUGETLB, we use MFD_HUGETLB instead. */ + .flag = MAP_SHARED, + }, }; _Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES, "Missing new backing src types?"); @@ -262,6 +267,7 @@ size_t get_backing_src_pagesz(uint32_t i) case VM_MEM_SRC_ANONYMOUS_THP: return get_trans_hugepagesz(); case VM_MEM_SRC_ANONYMOUS_HUGETLB: + case VM_MEM_SRC_SHARED_HUGETLB: return get_def_hugetlb_pagesz(); default: return MAP_HUGE_PAGE_SIZE(flag);
This lets us run the demand paging test on top of a shared hugetlbfs-backed area. The "shared" is key, as this allows us to exercise userfaultfd minor faults on hugetlbfs. Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> --- tools/testing/selftests/kvm/demand_paging_test.c | 6 ++++-- tools/testing/selftests/kvm/include/test_util.h | 10 ++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 9 +++++++-- tools/testing/selftests/kvm/lib/test_util.c | 6 ++++++ 4 files changed, 27 insertions(+), 4 deletions(-)