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 | #include <sys/resource.h> |
16 | |
17 | #include "test_util.h" |
18 | |
19 | #include "kvm_util.h" |
20 | #include "asm/kvm.h" |
21 | #include "linux/kvm.h" |
22 | |
23 | void test_vcpu_creation(int first_vcpu_id, int num_vcpus) |
24 | { |
25 | struct kvm_vm *vm; |
26 | int i; |
27 | |
28 | pr_info("Testing creating %d vCPUs, with IDs %d...%d.\n" , |
29 | num_vcpus, first_vcpu_id, first_vcpu_id + num_vcpus - 1); |
30 | |
31 | vm = vm_create_barebones(); |
32 | |
33 | for (i = first_vcpu_id; i < first_vcpu_id + num_vcpus; i++) |
34 | /* This asserts that the vCPU was created. */ |
35 | __vm_vcpu_add(vm, i); |
36 | |
37 | kvm_vm_free(vm); |
38 | } |
39 | |
40 | int main(int argc, char *argv[]) |
41 | { |
42 | int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID); |
43 | int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); |
44 | /* |
45 | * Number of file descriptors reqired, KVM_CAP_MAX_VCPUS for vCPU fds + |
46 | * an arbitrary number for everything else. |
47 | */ |
48 | int nr_fds_wanted = kvm_max_vcpus + 100; |
49 | struct rlimit rl; |
50 | |
51 | pr_info("KVM_CAP_MAX_VCPU_ID: %d\n" , kvm_max_vcpu_id); |
52 | pr_info("KVM_CAP_MAX_VCPUS: %d\n" , kvm_max_vcpus); |
53 | |
54 | /* |
55 | * Check that we're allowed to open nr_fds_wanted file descriptors and |
56 | * try raising the limits if needed. |
57 | */ |
58 | TEST_ASSERT(!getrlimit(RLIMIT_NOFILE, &rl), "getrlimit() failed!" ); |
59 | |
60 | if (rl.rlim_cur < nr_fds_wanted) { |
61 | rl.rlim_cur = nr_fds_wanted; |
62 | if (rl.rlim_max < nr_fds_wanted) { |
63 | int old_rlim_max = rl.rlim_max; |
64 | rl.rlim_max = nr_fds_wanted; |
65 | |
66 | int r = setrlimit(RLIMIT_NOFILE, &rl); |
67 | __TEST_REQUIRE(r >= 0, |
68 | "RLIMIT_NOFILE hard limit is too low (%d, wanted %d)" , |
69 | old_rlim_max, nr_fds_wanted); |
70 | } else { |
71 | TEST_ASSERT(!setrlimit(RLIMIT_NOFILE, &rl), "setrlimit() failed!" ); |
72 | } |
73 | } |
74 | |
75 | /* |
76 | * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID. |
77 | * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID |
78 | * in this case. |
79 | */ |
80 | if (!kvm_max_vcpu_id) |
81 | kvm_max_vcpu_id = kvm_max_vcpus; |
82 | |
83 | TEST_ASSERT(kvm_max_vcpu_id >= kvm_max_vcpus, |
84 | "KVM_MAX_VCPU_IDS (%d) must be at least as large as KVM_MAX_VCPUS (%d)." , |
85 | kvm_max_vcpu_id, kvm_max_vcpus); |
86 | |
87 | test_vcpu_creation(first_vcpu_id: 0, num_vcpus: kvm_max_vcpus); |
88 | |
89 | if (kvm_max_vcpu_id > kvm_max_vcpus) |
90 | test_vcpu_creation( |
91 | first_vcpu_id: kvm_max_vcpu_id - kvm_max_vcpus, num_vcpus: kvm_max_vcpus); |
92 | |
93 | return 0; |
94 | } |
95 | |