KVM: selftests: Cache list of MSRs to save/restore

Cache the list of MSRs to save restore, mostly to justify not freeing the
list in the caller, which simplifies consumption of the list.

Opportunistically move the XSS test's so called is_supported_msr() to
common code as kvm_msr_is_in_save_restore_list().  The XSS is "supported"
by KVM, it's simply not in the save/restore list because KVM doesn't yet
allow a non-zero value.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 6 insertions, 21 deletions

diff --git a/tools/testing/selftests/kvm/x86_64/xss_msr_test.c b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c
index 3529376747c2..7bd15f8a805c 100644
--- a/tools/testing/selftests/kvm/x86_64/xss_msr_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c
@@ -17,28 +17,11 @@
 
 #define X86_FEATURE_XSAVES	(1<<3)
 
-bool is_supported_msr(u32 msr_index)
-{
-	struct kvm_msr_list *list;
-	bool found = false;
-	int i;
-
-	list = kvm_get_msr_index_list();
-	for (i = 0; i < list->nmsrs; ++i) {
-		if (list->indices[i] == msr_index) {
-			found = true;
-			break;
-		}
-	}
-
-	free(list);
-	return found;
-}
-
 int main(int argc, char *argv[])
 {
 	struct kvm_cpuid_entry2 *entry;
 	bool xss_supported = false;
+	bool xss_in_msr_list;
 	struct kvm_vm *vm;
 	uint64_t xss_val;
 	int i, r;
@@ -64,12 +47,14 @@ int main(int argc, char *argv[])
 	 * At present, KVM only supports a guest IA32_XSS value of 0. Verify
 	 * that trying to set the guest IA32_XSS to an unsupported value fails.
 	 * Also, in the future when a non-zero value succeeds check that
-	 * IA32_XSS is in the KVM_GET_MSR_INDEX_LIST.
+	 * IA32_XSS is in the list of MSRs to save/restore.
 	 */
+	xss_in_msr_list = kvm_msr_is_in_save_restore_list(MSR_IA32_XSS);
 	for (i = 0; i < MSR_BITS; ++i) {
 		r = _vcpu_set_msr(vm, VCPU_ID, MSR_IA32_XSS, 1ull << i);
-		TEST_ASSERT(r == 0 || is_supported_msr(MSR_IA32_XSS),
-			    "IA32_XSS was able to be set, but was not found in KVM_GET_MSR_INDEX_LIST.\n");
+
+		TEST_ASSERT(r == 0 || xss_in_msr_list,
+			    "IA32_XSS was able to be set, but was not in save/restore list");
 	}
 
 	kvm_vm_free(vm);