1 files changed, 54 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/set_sregs_test.c b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
new file mode 100644
index 000000000000..35640e8e95bc
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
@@ -0,0 +1,54 @@
+/*
+ * KVM_SET_SREGS tests
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ * This is a regression test for the bug fixed by the following commit:
+ * d3802286fa0f ("kvm: x86: Disallow illegal IA32_APIC_BASE MSR values")
+ *
+ * That bug allowed a user-mode program that called the KVM_SET_SREGS
+ * ioctl to put a VCPU's local APIC into an invalid state.
+ *
+ */
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+#include "processor.h"
+
+#define VCPU_ID                  5
+
+int main(int argc, char *argv[])
+{
+	struct kvm_sregs sregs;
+	struct kvm_vm *vm;
+	int rc;
+
+	/* Tell stdout not to buffer its content */
+	setbuf(stdout, NULL);
+
+	/* Create VM */
+	vm = vm_create_default(VCPU_ID, 0, NULL);
+
+	vcpu_sregs_get(vm, VCPU_ID, &sregs);
+	sregs.apic_base = 1 << 10;
+	rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
+	TEST_ASSERT(rc, "Set IA32_APIC_BASE to %llx (invalid)",
+		    sregs.apic_base);
+	sregs.apic_base = 1 << 11;
+	rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
+	TEST_ASSERT(!rc, "Couldn't set IA32_APIC_BASE to %llx (valid)",
+		    sregs.apic_base);
+
+	kvm_vm_free(vm);
+
+	return 0;
+}