[PATCH v3 4/6] selftests: KVM: Separate static alloc from KVM_GET_SUPPORTED_CPUID call

[Oliver Upton <oupton@google.com>]

The library code allows for a single allocation of CPUID to store the
value returned by KVM_GET_SUPPORTED_CPUID. Subsequent calls to the
helper simply return a pointer to the aforementioned allocation. A
subsequent change introduces a selftest that contains test cases which
adjust the CPUID value before calling KVM_SET_CPUID2. Using a single
definition of CPUID is problematic, as the changes are not isolated to a
single test case.

Create a helper that allocates memory for CPUID on a per-call basis.

Signed-off-by: Oliver Upton <oupton@google.com>
---
 .../selftests/kvm/include/x86_64/processor.h  |  1 +
 .../selftests/kvm/lib/x86_64/processor.c      | 33 +++++++++++++++----
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 8a470da7b71a..e36ab7de7717 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -390,6 +390,7 @@ void kvm_x86_state_cleanup(struct kvm_x86_state *state);
 
 struct kvm_msr_list *kvm_get_msr_index_list(void);
 uint64_t kvm_get_feature_msr(uint64_t msr_index);
+struct kvm_cpuid2 *_kvm_get_supported_cpuid(void);
 struct kvm_cpuid2 *kvm_get_supported_cpuid(void);
 
 struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vm *vm, uint32_t vcpuid);
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 9f000dfb5594..b8921cd09ede 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -772,17 +772,14 @@ static struct kvm_cpuid2 *allocate_kvm_cpuid2(void)
  *
  * Return: The supported KVM CPUID
  *
- * Get the guest CPUID supported by KVM.
+ * Gets the supported guest CPUID with the KVM_GET_SUPPORTED_CPUID ioctl.
  */
-struct kvm_cpuid2 *kvm_get_supported_cpuid(void)
+struct kvm_cpuid2 *_kvm_get_supported_cpuid(void)
 {
-	static struct kvm_cpuid2 *cpuid;
+	struct kvm_cpuid2 *cpuid;
 	int ret;
 	int kvm_fd;
 
-	if (cpuid)
-		return cpuid;
-
 	cpuid = allocate_kvm_cpuid2();
 	kvm_fd = open_kvm_dev_path_or_exit();
 
@@ -794,6 +791,30 @@ struct kvm_cpuid2 *kvm_get_supported_cpuid(void)
 	return cpuid;
 }
 
+/*
+ * KVM Supported CPUID Get
+ *
+ * Input Args: None
+ *
+ * Output Args: None
+ *
+ * Return: The supported KVM CPUID
+ *
+ * Gets the supported guest CPUID with the KVM_GET_SUPPORTED_CPUID ioctl.
+ * The first call creates a static allocation of CPUID for the process.
+ * Subsequent calls will return a pointer to the previously allocated CPUID.
+ */
+struct kvm_cpuid2 *kvm_get_supported_cpuid(void)
+{
+	static struct kvm_cpuid2 *cpuid;
+
+	if (cpuid)
+		return cpuid;
+
+	cpuid = _kvm_get_supported_cpuid();
+	return cpuid;
+}
+
 /*
  * KVM Get MSR
  *
-- 
2.35.1.574.g5d30c73bfb-goog