KVM: selftests: Convert vmx_tsc_adjust_test away from VCPU_ID

Convert vmx_tsc_adjust_test to use vm_create_with_one_vcpu() and pass
around a 'struct kvm_vcpu' object instead of using a global VCPU_ID.
Note, this is a "functional" change in the sense that the test now
creates a vCPU with vcpu_id==0 instead of vcpu_id==5.  The non-zero
VCPU_ID was 100% arbitrary and added little to no validation coverage.
If testing non-zero vCPU IDs is desirable for generic tests, that can be
done in the future by tweaking the VM creation helpers.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c

@@ -32,8 +32,6 @@
 #define MSR_IA32_TSC_ADJUST 0x3b
 #endif
 
-#define VCPU_ID		5
-
 #define TSC_ADJUST_VALUE (1ll << 32)
 #define TSC_OFFSET_VALUE -(1ll << 48)
 
@@ -127,26 +125,27 @@ static void report(int64_t val)
 int main(int argc, char *argv[])
 {
 	vm_vaddr_t vmx_pages_gva;
+	struct kvm_vcpu *vcpu;
 
 	nested_vmx_check_supported();
 
-	vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code);
+	vm = vm_create_with_one_vcpu(&vcpu, (void *) l1_guest_code);
 
 	/* Allocate VMX pages and shared descriptors (vmx_pages). */
 	vcpu_alloc_vmx(vm, &vmx_pages_gva);
-	vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
+	vcpu_args_set(vm, vcpu->id, 1, vmx_pages_gva);
 
 	for (;;) {
-		volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+		volatile struct kvm_run *run = vcpu->run;
 		struct ucall uc;
 
-		vcpu_run(vm, VCPU_ID);
+		vcpu_run(vm, vcpu->id);
 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 			    "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
 			    run->exit_reason,
 			    exit_reason_str(run->exit_reason));
 
-		switch (get_ucall(vm, VCPU_ID, &uc)) {
+		switch (get_ucall(vm, vcpu->id, &uc)) {
 		case UCALL_ABORT:
 			TEST_FAIL("%s", (const char *)uc.args[0]);
 			/* NOT REACHED */