xref: /linux/tools/testing/selftests/kvm/x86/hyperv_cpuid.c (revision 5d6ba5ab8582aa35c1ee98e47af28e6f6772596c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Test for x86 KVM_CAP_HYPERV_CPUID
4  *
5  * Copyright (C) 2018, Red Hat, Inc.
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2.
8  *
9  */
10 #include <fcntl.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <sys/ioctl.h>
15 
16 #include "test_util.h"
17 #include "kvm_util.h"
18 #include "processor.h"
19 #include "vmx.h"
20 
guest_code(void)21 static void guest_code(void)
22 {
23 }
24 
smt_possible(void)25 static bool smt_possible(void)
26 {
27 	char buf[16];
28 	FILE *f;
29 	bool res = true;
30 
31 	f = fopen("/sys/devices/system/cpu/smt/control", "r");
32 	if (f) {
33 		if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
34 			if (!strncmp(buf, "forceoff", 8) ||
35 			    !strncmp(buf, "notsupported", 12))
36 				res = false;
37 		}
38 		fclose(f);
39 	}
40 
41 	return res;
42 }
43 
test_hv_cpuid(struct kvm_vcpu * vcpu,bool evmcs_expected)44 static void test_hv_cpuid(struct kvm_vcpu *vcpu, bool evmcs_expected)
45 {
46 	const bool has_irqchip = !vcpu || vcpu->vm->has_irqchip;
47 	const struct kvm_cpuid2 *hv_cpuid_entries;
48 	int i;
49 	int nent_expected = 10;
50 	u32 test_val;
51 
52 	if (vcpu)
53 		hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vcpu);
54 	else
55 		hv_cpuid_entries = kvm_get_supported_hv_cpuid();
56 
57 	TEST_ASSERT(hv_cpuid_entries->nent == nent_expected,
58 		    "KVM_GET_SUPPORTED_HV_CPUID should return %d entries"
59 		    " (returned %d)",
60 		    nent_expected, hv_cpuid_entries->nent);
61 
62 	for (i = 0; i < hv_cpuid_entries->nent; i++) {
63 		const struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
64 
65 		TEST_ASSERT((entry->function >= 0x40000000) &&
66 			    (entry->function <= 0x40000082),
67 			    "function %x is our of supported range",
68 			    entry->function);
69 
70 		TEST_ASSERT(entry->index == 0,
71 			    ".index field should be zero");
72 
73 		TEST_ASSERT(entry->flags == 0,
74 			    ".flags field should be zero");
75 
76 		TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
77 			    !entry->padding[2], "padding should be zero");
78 
79 		switch (entry->function) {
80 		case 0x40000000:
81 			test_val = 0x40000082;
82 
83 			TEST_ASSERT(entry->eax == test_val,
84 				    "Wrong max leaf report in 0x40000000.EAX: %x"
85 				    " (evmcs=%d)",
86 				    entry->eax, evmcs_expected
87 				);
88 			break;
89 		case 0x40000003:
90 			TEST_ASSERT(has_irqchip || !(entry->edx & BIT(19)),
91 				    "\"Direct\" Synthetic Timers should require in-kernel APIC");
92 			break;
93 		case 0x40000004:
94 			test_val = entry->eax & (1UL << 18);
95 
96 			TEST_ASSERT(!!test_val == !smt_possible(),
97 				    "NoNonArchitecturalCoreSharing bit"
98 				    " doesn't reflect SMT setting");
99 
100 			TEST_ASSERT(has_irqchip || !(entry->eax & BIT(10)),
101 				    "Cluster IPI (i.e. SEND_IPI) should require in-kernel APIC");
102 			break;
103 		case 0x4000000A:
104 			TEST_ASSERT(entry->eax & (1UL << 19),
105 				    "Enlightened MSR-Bitmap should always be supported"
106 				    " 0x40000000.EAX: %x", entry->eax);
107 			if (evmcs_expected)
108 				TEST_ASSERT((entry->eax & 0xffff) == 0x101,
109 				    "Supported Enlightened VMCS version range is supposed to be 1:1"
110 				    " 0x40000000.EAX: %x", entry->eax);
111 
112 			break;
113 		default:
114 			break;
115 
116 		}
117 		/*
118 		 * If needed for debug:
119 		 * fprintf(stdout,
120 		 *	"CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
121 		 *	entry->function, entry->eax, entry->ebx, entry->ecx,
122 		 *	entry->edx);
123 		 */
124 	}
125 
126 	/*
127 	 * Note, the CPUID array returned by the system-scoped helper is a one-
128 	 * time allocation, i.e. must not be freed.
129 	 */
130 	if (vcpu)
131 		free((void *)hv_cpuid_entries);
132 }
133 
test_hv_cpuid_e2big(struct kvm_vm * vm,struct kvm_vcpu * vcpu)134 static void test_hv_cpuid_e2big(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
135 {
136 	static struct kvm_cpuid2 cpuid = {.nent = 0};
137 	int ret;
138 
139 	if (vcpu)
140 		ret = __vcpu_ioctl(vcpu, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
141 	else
142 		ret = __kvm_ioctl(vm->kvm_fd, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
143 
144 	TEST_ASSERT(ret == -1 && errno == E2BIG,
145 		    "%s KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
146 		    " it should have: %d %d", !vcpu ? "KVM" : "vCPU", ret, errno);
147 }
148 
main(int argc,char * argv[])149 int main(int argc, char *argv[])
150 {
151 	struct kvm_vm *vm;
152 	struct kvm_vcpu *vcpu;
153 
154 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
155 
156 	/* Test the vCPU ioctl without an in-kernel local APIC. */
157 	vm = vm_create_barebones();
158 	vcpu = __vm_vcpu_add(vm, 0);
159 	test_hv_cpuid(vcpu, false);
160 	kvm_vm_free(vm);
161 
162 	/* Test vCPU ioctl version */
163 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
164 	test_hv_cpuid_e2big(vm, vcpu);
165 	test_hv_cpuid(vcpu, false);
166 
167 	if (!kvm_cpu_has(X86_FEATURE_VMX) ||
168 	    !kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
169 		print_skip("Enlightened VMCS is unsupported");
170 		goto do_sys;
171 	}
172 	vcpu_enable_evmcs(vcpu);
173 	test_hv_cpuid(vcpu, true);
174 
175 do_sys:
176 	/* Test system ioctl version */
177 	if (!kvm_has_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
178 		print_skip("KVM_CAP_SYS_HYPERV_CPUID not supported");
179 		goto out;
180 	}
181 
182 	test_hv_cpuid_e2big(vm, NULL);
183 	test_hv_cpuid(NULL, kvm_cpu_has(X86_FEATURE_VMX));
184 
185 out:
186 	kvm_vm_free(vm);
187 
188 	return 0;
189 }
190