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Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Wed, 10 Feb 2021 15:06:21 -0800
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Subject: [PATCH 11/15] KVM: selftests: Create VM with adjusted number of guest
 pages for perf tests
From:   Sean Christopherson <seanjc@google.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Sean Christopherson <seanjc@google.com>,
        Ben Gardon <bgardon@google.com>,
        Yanan Wang <wangyanan55@huawei.com>,
        Andrew Jones <drjones@redhat.com>,
        Peter Xu <peterx@redhat.com>,
        Aaron Lewis <aaronlewis@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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@google.com>
---
 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