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 #include <sys/resource.h> 14 15 #include "test_util.h" 16 17 #include "kvm_util.h" 18 #include "asm/kvm.h" 19 #include "linux/kvm.h" 20 21 void test_vcpu_creation(int first_vcpu_id, int num_vcpus) 22 { 23 struct kvm_vm *vm; 24 int i; 25 26 pr_info("Testing creating %d vCPUs, with IDs %d...%d.\n", 27 num_vcpus, first_vcpu_id, first_vcpu_id + num_vcpus - 1); 28 29 vm = vm_create_barebones(); 30 31 for (i = first_vcpu_id; i < first_vcpu_id + num_vcpus; i++) 32 /* This asserts that the vCPU was created. */ 33 __vm_vcpu_add(vm, i); 34 35 kvm_vm_free(vm); 36 } 37 38 int main(int argc, char *argv[]) 39 { 40 int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID); 41 int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 42 /* 43 * Number of file descriptors reqired, KVM_CAP_MAX_VCPUS for vCPU fds + 44 * an arbitrary number for everything else. 45 */ 46 int nr_fds_wanted = kvm_max_vcpus + 100; 47 struct rlimit rl; 48 49 pr_info("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id); 50 pr_info("KVM_CAP_MAX_VCPUS: %d\n", kvm_max_vcpus); 51 52 /* 53 * Check that we're allowed to open nr_fds_wanted file descriptors and 54 * try raising the limits if needed. 55 */ 56 TEST_ASSERT(!getrlimit(RLIMIT_NOFILE, &rl), "getrlimit() failed!"); 57 58 if (rl.rlim_cur < nr_fds_wanted) { 59 rl.rlim_cur = nr_fds_wanted; 60 if (rl.rlim_max < nr_fds_wanted) { 61 int old_rlim_max = rl.rlim_max; 62 rl.rlim_max = nr_fds_wanted; 63 64 int r = setrlimit(RLIMIT_NOFILE, &rl); 65 __TEST_REQUIRE(r >= 0, 66 "RLIMIT_NOFILE hard limit is too low (%d, wanted %d)", 67 old_rlim_max, nr_fds_wanted); 68 } else { 69 TEST_ASSERT(!setrlimit(RLIMIT_NOFILE, &rl), "setrlimit() failed!"); 70 } 71 } 72 73 /* 74 * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID. 75 * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID 76 * in this case. 77 */ 78 if (!kvm_max_vcpu_id) 79 kvm_max_vcpu_id = kvm_max_vcpus; 80 81 TEST_ASSERT(kvm_max_vcpu_id >= kvm_max_vcpus, 82 "KVM_MAX_VCPU_IDS (%d) must be at least as large as KVM_MAX_VCPUS (%d).", 83 kvm_max_vcpu_id, kvm_max_vcpus); 84 85 test_vcpu_creation(0, kvm_max_vcpus); 86 87 if (kvm_max_vcpu_id > kvm_max_vcpus) 88 test_vcpu_creation( 89 kvm_max_vcpu_id - kvm_max_vcpus, kvm_max_vcpus); 90 91 return 0; 92 } 93