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(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR); 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 if (r < 0) { 68 printf("RLIMIT_NOFILE hard limit is too low (%d, wanted %d)\n", 69 old_rlim_max, nr_fds_wanted); 70 exit(KSFT_SKIP); 71 } 72 } else { 73 TEST_ASSERT(!setrlimit(RLIMIT_NOFILE, &rl), "setrlimit() failed!"); 74 } 75 } 76 77 /* 78 * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID. 79 * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID 80 * in this case. 81 */ 82 if (!kvm_max_vcpu_id) 83 kvm_max_vcpu_id = kvm_max_vcpus; 84 85 TEST_ASSERT(kvm_max_vcpu_id >= kvm_max_vcpus, 86 "KVM_MAX_VCPU_IDS (%d) must be at least as large as KVM_MAX_VCPUS (%d).", 87 kvm_max_vcpu_id, kvm_max_vcpus); 88 89 test_vcpu_creation(0, kvm_max_vcpus); 90 91 if (kvm_max_vcpu_id > kvm_max_vcpus) 92 test_vcpu_creation( 93 kvm_max_vcpu_id - kvm_max_vcpus, kvm_max_vcpus); 94 95 return 0; 96 } 97