KVM: selftests: evmcs_test: Test that KVM_STATE_NESTED_EVMCS is never lost

Do KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE for a freshly restored VM
(before the first KVM_RUN) to check that KVM_STATE_NESTED_EVMCS is not
lost.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210526132026.270394-12-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
index d058d9e..d0a7a99 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -112,14 +112,38 @@ void inject_nmi(struct kvm_vm *vm)
        vcpu_events_set(vm, VCPU_ID, &events);
 }
 
+static void save_restore_vm(struct kvm_vm *vm)
+{
+       struct kvm_regs regs1, regs2;
+       struct kvm_x86_state *state;
+
+       state = vcpu_save_state(vm, VCPU_ID);
+       memset(&regs1, 0, sizeof(regs1));
+       vcpu_regs_get(vm, VCPU_ID, &regs1);
+
+       kvm_vm_release(vm);
+
+       /* Restore state in a new VM.  */
+       kvm_vm_restart(vm, O_RDWR);
+       vm_vcpu_add(vm, VCPU_ID);
+       vcpu_set_hv_cpuid(vm, VCPU_ID);
+       vcpu_enable_evmcs(vm, VCPU_ID);
+       vcpu_load_state(vm, VCPU_ID, state);
+       free(state);
+
+       memset(&regs2, 0, sizeof(regs2));
+       vcpu_regs_get(vm, VCPU_ID, &regs2);
+       TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
+                   "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
+                   (ulong) regs2.rdi, (ulong) regs2.rsi);
+}
+
 int main(int argc, char *argv[])
 {
        vm_vaddr_t vmx_pages_gva = 0;
 
-       struct kvm_regs regs1, regs2;
        struct kvm_vm *vm;
        struct kvm_run *run;
-       struct kvm_x86_state *state;
        struct ucall uc;
        int stage;
 
@@ -136,10 +160,6 @@ int main(int argc, char *argv[])
        vcpu_set_hv_cpuid(vm, VCPU_ID);
        vcpu_enable_evmcs(vm, VCPU_ID);
 
-       run = vcpu_state(vm, VCPU_ID);
-
-       vcpu_regs_get(vm, VCPU_ID, &regs1);
-
        vcpu_alloc_vmx(vm, &vmx_pages_gva);
        vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
 
@@ -151,6 +171,7 @@ int main(int argc, char *argv[])
        pr_info("Running L1 which uses EVMCS to run L2\n");
 
        for (stage = 1;; stage++) {
+               run = vcpu_state(vm, VCPU_ID);
                _vcpu_run(vm, VCPU_ID);
                TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
                            "Stage %d: unexpected exit reason: %u (%s),\n",
@@ -175,32 +196,23 @@ int main(int argc, char *argv[])
                            uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
                            stage, (ulong)uc.args[1]);
 
-               state = vcpu_save_state(vm, VCPU_ID);
-               memset(&regs1, 0, sizeof(regs1));
-               vcpu_regs_get(vm, VCPU_ID, &regs1);
-
-               kvm_vm_release(vm);
-
-               /* Restore state in a new VM.  */
-               kvm_vm_restart(vm, O_RDWR);
-               vm_vcpu_add(vm, VCPU_ID);
-               vcpu_set_hv_cpuid(vm, VCPU_ID);
-               vcpu_enable_evmcs(vm, VCPU_ID);
-               vcpu_load_state(vm, VCPU_ID, state);
-               run = vcpu_state(vm, VCPU_ID);
-               free(state);
-
-               memset(&regs2, 0, sizeof(regs2));
-               vcpu_regs_get(vm, VCPU_ID, &regs2);
-               TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
-                           "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
-                           (ulong) regs2.rdi, (ulong) regs2.rsi);
+               save_restore_vm(vm);
 
                /* Force immediate L2->L1 exit before resuming */
                if (stage == 8) {
                        pr_info("Injecting NMI into L1 before L2 had a chance to run after restore\n");
                        inject_nmi(vm);
                }
+
+               /*
+                * Do KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE for a freshly
+                * restored VM (before the first KVM_RUN) to check that
+                * KVM_STATE_NESTED_EVMCS is not lost.
+                */
+               if (stage == 9) {
+                       pr_info("Trying extra KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE cycle\n");
+                       save_restore_vm(vm);
+               }
        }
 
 done: