From: Sean Christopherson <seanjc@xxxxxxxxxx>
Assert that the GPA for a memslot backed by a hugepage is aligned to
the hugepage size and fix perf_test_util accordingly. Lack of GPA
alignment prevents KVM from backing the guest with hugepages, e.g. x86's
write-protection of hugepages when dirty logging is activated is
otherwise not exercised.
Add a comment explaining that guest_page_size is for non-huge pages to
try and avoid confusion about what it actually tracks.
Cc: Ben Gardon <bgardon@xxxxxxxxxx>
Cc: Yanan Wang <wangyanan55@xxxxxxxxxx>
Cc: Andrew Jones <drjones@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Aaron Lewis <aaronlewis@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
[Used get_backing_src_pagesz() to determine alignment dynamically.]
Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/kvm_util.c | 2 ++
tools/testing/selftests/kvm/lib/perf_test_util.c | 7 ++++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 07f37456bba0..1f6a01c33dce 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -875,6 +875,8 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
if (src_type == VM_MEM_SRC_ANONYMOUS_THP)
alignment = max(backing_src_pagesz, alignment);
+ ASSERT_EQ(guest_paddr, align_up(guest_paddr, backing_src_pagesz));
+
/* Add enough memory to align up if necessary */
if (alignment > 1)
region->mmap_size += alignment;
diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
index 6b8d5020dc54..a015f267d945 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
@@ -55,11 +55,16 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
{
struct kvm_vm *vm;
uint64_t guest_num_pages;
+ uint64_t backing_src_pagesz = get_backing_src_pagesz(backing_src);
int i;
pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
perf_test_args.host_page_size = getpagesize();
+ /*
+ * Snapshot the non-huge page size. This is used by the guest code to
+ * access/dirty pages at the logging granularity.
+ */
perf_test_args.guest_page_size = vm_guest_mode_params[mode].page_size;
guest_num_pages = vm_adjust_num_guest_pages(mode,
@@ -92,7 +97,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
perf_test_args.guest_page_size;
- guest_test_phys_mem = align_down(guest_test_phys_mem, perf_test_args.host_page_size);
+ guest_test_phys_mem = align_down(guest_test_phys_mem, backing_src_pagesz);
#ifdef __s390x__
/* Align to 1M (segment size) */
guest_test_phys_mem = align_down(guest_test_phys_mem, 1 << 20);
--
2.34.0.rc1.387.gb447b232ab-goog
