kvm_create_max_vcpus.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * kvm_create_max_vcpus
 4 *
 5 * Copyright (C) 2019, Google LLC.
 6 *
 7 * Test for KVM_CAP_MAX_VCPUS and KVM_CAP_MAX_VCPU_ID.
 8 */
 9#include <fcntl.h>
10#include <stdio.h>
11#include <stdlib.h>
12#include <string.h>
13
14#include "test_util.h"
15
16#include "kvm_util.h"
17#include "asm/kvm.h"
18#include "linux/kvm.h"
19
20void test_vcpu_creation(int first_vcpu_id, int num_vcpus)
21{
22	struct kvm_vm *vm;
23	int i;
24
25	pr_info("Testing creating %d vCPUs, with IDs %d...%d.\n",
26		num_vcpus, first_vcpu_id, first_vcpu_id + num_vcpus - 1);
27
28	vm = vm_create_barebones();
29
30	for (i = first_vcpu_id; i < first_vcpu_id + num_vcpus; i++)
31		/* This asserts that the vCPU was created. */
32		__vm_vcpu_add(vm, i);
33
34	kvm_vm_free(vm);
35}
36
37int main(int argc, char *argv[])
38{
39	int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID);
40	int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
41
42	pr_info("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id);
43	pr_info("KVM_CAP_MAX_VCPUS: %d\n", kvm_max_vcpus);
44
45	kvm_set_files_rlimit(kvm_max_vcpus);
46
47	/*
48	 * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID.
49	 * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID
50	 * in this case.
51	 */
52	if (!kvm_max_vcpu_id)
53		kvm_max_vcpu_id = kvm_max_vcpus;
54
55	TEST_ASSERT(kvm_max_vcpu_id >= kvm_max_vcpus,
56		    "KVM_MAX_VCPU_IDS (%d) must be at least as large as KVM_MAX_VCPUS (%d).",
57		    kvm_max_vcpu_id, kvm_max_vcpus);
58
59	test_vcpu_creation(0, kvm_max_vcpus);
60
61	if (kvm_max_vcpu_id > kvm_max_vcpus)
62		test_vcpu_creation(
63			kvm_max_vcpu_id - kvm_max_vcpus, kvm_max_vcpus);
64
65	return 0;
66}