[PATCH 11/15] KVM: selftests: Create VM with adjusted number of guest pages for perf tests

From: Sean Christopherson
Date: Wed Feb 10 2021 - 18:13:31 EST


Use the already computed guest_num_pages when creating the so called
extra VM pages for a perf test, and add a comment explaining why the
pages are allocated as extra pages.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/perf_test_util.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
index 982a86c8eeaa..9b0cfdf10772 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
@@ -71,9 +71,12 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
TEST_ASSERT(vcpu_memory_bytes % pta->guest_page_size == 0,
"Guest memory size is not guest page size aligned.");

- vm = vm_create_with_vcpus(mode, vcpus,
- (vcpus * vcpu_memory_bytes) / pta->guest_page_size,
- 0, guest_code, NULL);
+ /*
+ * Pass guest_num_pages to populate the page tables for test memory.
+ * The memory is also added to memslot 0, but that's a benign side
+ * effect as KVM allows aliasing HVAs in memslots.
+ */
+ vm = vm_create_with_vcpus(mode, vcpus, 0, guest_num_pages, guest_code, NULL);
pta->vm = vm;

/*
--
2.30.0.478.g8a0d178c01-goog