From c071ff41e1502990a0902c7c3fcf72a462e46330 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 11 Nov 2021 00:03:00 +0000 Subject: KVM: selftests: Expose align() helpers to tests Refactor align() to work with non-pointers and split into separate helpers for aligning up vs. down. Add align_ptr_up() for use with pointers. Expose all helpers so that they can be used by tests and/or other utilities. The align_down() helper in particular will be used to ensure gpa alignment for hugepages. No functional change intended. [Added sepearate up/down helpers and replaced open-coded alignment bit math throughout the KVM selftests.] Signed-off-by: Sean Christopherson Signed-off-by: David Matlack Reviewed-by: Ben Gardon Message-Id: <20211111000310.1435032-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/include/test_util.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'tools/testing/selftests/kvm/include/test_util.h') diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index f8fddc84c0d3..78c06310cc0e 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -117,4 +117,29 @@ static inline bool backing_src_is_shared(enum vm_mem_backing_src_type t) return vm_mem_backing_src_alias(t)->flag & MAP_SHARED; } +/* Aligns x up to the next multiple of size. Size must be a power of 2. */ +static inline uint64_t align_up(uint64_t x, uint64_t size) +{ + uint64_t mask = size - 1; + + TEST_ASSERT(size != 0 && !(size & (size - 1)), + "size not a power of 2: %lu", size); + return ((x + mask) & ~mask); +} + +static inline uint64_t align_down(uint64_t x, uint64_t size) +{ + uint64_t x_aligned_up = align_up(x, size); + + if (x == x_aligned_up) + return x; + else + return x_aligned_up - size; +} + +static inline void *align_ptr_up(void *x, size_t size) +{ + return (void *)align_up((unsigned long)x, size); +} + #endif /* SELFTEST_KVM_TEST_UTIL_H */ -- cgit v1.2.3 From f4870ef3e15ab889a689f99a579fe0fe7c53a960 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 11 Nov 2021 00:03:01 +0000 Subject: KVM: selftests: Assert mmap HVA is aligned when using HugeTLB Manually padding and aligning the mmap region is only needed when using THP. When using HugeTLB, mmap will always return an address aligned to the HugeTLB page size. Add a comment to clarify this and assert the mmap behavior for HugeTLB. [Removed requirement that HugeTLB mmaps must be padded per Yanan's feedback and added assertion that mmap returns aligned addresses when using HugeTLB.] Cc: Ben Gardon Cc: Yanan Wang Cc: Andrew Jones Cc: Peter Xu Cc: Aaron Lewis Signed-off-by: Sean Christopherson Signed-off-by: David Matlack Message-Id: <20211111000310.1435032-4-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/include/test_util.h | 1 + tools/testing/selftests/kvm/lib/kvm_util.c | 11 +++++++++++ tools/testing/selftests/kvm/lib/test_util.c | 5 +++++ 3 files changed, 17 insertions(+) (limited to 'tools/testing/selftests/kvm/include/test_util.h') diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index 78c06310cc0e..99e0dcdc923f 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -104,6 +104,7 @@ size_t get_trans_hugepagesz(void); size_t get_def_hugetlb_pagesz(void); const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i); size_t get_backing_src_pagesz(uint32_t i); +bool is_backing_src_hugetlb(uint32_t i); void backing_src_help(const char *flag); enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name); long get_run_delay(void); diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 63375118d48f..07f37456bba0 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -866,6 +866,12 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, alignment = 1; #endif + /* + * When using THP mmap is not guaranteed to returned a hugepage aligned + * address so we have to pad the mmap. Padding is not needed for HugeTLB + * because mmap will always return an address aligned to the HugeTLB + * page size. + */ if (src_type == VM_MEM_SRC_ANONYMOUS_THP) alignment = max(backing_src_pagesz, alignment); @@ -901,6 +907,11 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, "test_malloc failed, mmap_start: %p errno: %i", region->mmap_start, errno); + TEST_ASSERT(!is_backing_src_hugetlb(src_type) || + region->mmap_start == align_ptr_up(region->mmap_start, backing_src_pagesz), + "mmap_start %p is not aligned to HugeTLB page size 0x%lx", + region->mmap_start, backing_src_pagesz); + /* Align host address */ region->host_mem = align_ptr_up(region->mmap_start, alignment); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index b72429108993..6d23878bbfe1 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -283,6 +283,11 @@ size_t get_backing_src_pagesz(uint32_t i) } } +bool is_backing_src_hugetlb(uint32_t i) +{ + return !!(vm_mem_backing_src_alias(i)->flag & MAP_HUGETLB); +} + static void print_available_backing_src_types(const char *prefix) { int i; -- cgit v1.2.3