[PATCH 4/5] KVM: selftests: Use for-loop to handle all successful SEV migrations

[Sean Christopherson <seanjc@google.com>]

Use the main for-loop in the "SEV migrate from" testcase to handle all
successful migrations, as there is nothing inherently unique about the
original source VM beyond it needing to be created as an SEV VM.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../selftests/kvm/x86/sev_migrate_tests.c     | 31 +++++++++----------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
index 0580bee5888e..b501c916edf5 100644
--- a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
+++ b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
@@ -14,7 +14,7 @@
 #include "kselftest.h"
 
 #define NR_MIGRATE_TEST_VCPUS 4
-#define NR_MIGRATE_TEST_VMS 3
+#define NR_MIGRATE_TEST_VMS 4
 #define NR_LOCK_TESTING_THREADS 3
 #define NR_LOCK_TESTING_ITERATIONS 10000
 
@@ -72,26 +72,23 @@ static void sev_migrate_from(struct kvm_vm *dst, struct kvm_vm *src)
 
 static void test_sev_migrate_from(bool es)
 {
-	struct kvm_vm *src_vm;
-	struct kvm_vm *dst_vms[NR_MIGRATE_TEST_VMS];
-	int i, ret;
+	struct kvm_vm *vms[NR_MIGRATE_TEST_VMS];
+	int i;
 
-	src_vm = sev_vm_create(es);
-	for (i = 0; i < NR_MIGRATE_TEST_VMS; ++i)
-		dst_vms[i] = aux_vm_create(true);
-
-	/* Initial migration from the src to the first dst. */
-	sev_migrate_from(dst_vms[0], src_vm);
-
-	for (i = 1; i < NR_MIGRATE_TEST_VMS; i++)
-		sev_migrate_from(dst_vms[i], dst_vms[i - 1]);
+	vms[0] = sev_vm_create(es);
+	for (i = 1; i < NR_MIGRATE_TEST_VMS; ++i)
+		vms[i] = aux_vm_create(true);
 
-	/* Migrate the guest back to the original VM. */
-	sev_migrate_from(src_vm, dst_vms[NR_MIGRATE_TEST_VMS - 1]);
+	/*
+	 * Migrate in N times, in a chain from the initial SEV VM to each "aux"
+	 * VM, and finally back to the original SEV VM.  KVM disallows KVM_RUN
+	 * on the source after migration, but all other ioctls should succeed.
+	 */
+	for (i = 0; i < NR_MIGRATE_TEST_VMS; i++)
+		sev_migrate_from(vms[(i + 1) % NR_MIGRATE_TEST_VMS], vms[i]);
 
-	kvm_vm_free(src_vm);
 	for (i = 0; i < NR_MIGRATE_TEST_VMS; ++i)
-		kvm_vm_free(dst_vms[i]);
+		kvm_vm_free(vms[i]);
 }
 
 struct locking_thread_input {
-- 
2.50.1.552.g942d659e1b-goog