tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
10#define _GNU_SOURCE /* for program_invocation_short_name */
11#include <fcntl.h>
12#include <stdio.h>
13#include <stdlib.h>
14#include <string.h>
15
16#include "test_util.h"
17
18#include "kvm_util.h"
19#include "asm/kvm.h"
20#include "linux/kvm.h"
21
22void test_vcpu_creation(int first_vcpu_id, int num_vcpus)
23{
24 struct kvm_vm *vm;
25 int i;
26
27 printf("Testing creating %d vCPUs, with IDs %d...%d.\n",
28 num_vcpus, first_vcpu_id, first_vcpu_id + num_vcpus - 1);
29
30 vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
31
32 for (i = 0; i < num_vcpus; i++) {
33 int vcpu_id = first_vcpu_id + i;
34
35 /* This asserts that the vCPU was created. */
36 vm_vcpu_add(vm, vcpu_id);
37 }
38
39 kvm_vm_free(vm);
40}
41
42int main(int argc, char *argv[])
43{
44 int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID);
45 int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
46
47 printf("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id);
48 printf("KVM_CAP_MAX_VCPUS: %d\n", kvm_max_vcpus);
49
50 /*
51 * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID.
52 * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID
53 * in this case.
54 */
55 if (!kvm_max_vcpu_id)
56 kvm_max_vcpu_id = kvm_max_vcpus;
57
58 TEST_ASSERT(kvm_max_vcpu_id >= kvm_max_vcpus,
59 "KVM_MAX_VCPU_ID (%d) must be at least as large as KVM_MAX_VCPUS (%d).",
60 kvm_max_vcpu_id, kvm_max_vcpus);
61
62 test_vcpu_creation(0, kvm_max_vcpus);
63
64 if (kvm_max_vcpu_id > kvm_max_vcpus)
65 test_vcpu_creation(
66 kvm_max_vcpu_id - kvm_max_vcpus, kvm_max_vcpus);
67
68 return 0;
69}