xref: /freebsd/sys/amd64/vmm/x86.c (revision 730cecb05aaf016ac52ef7cfc691ccec3a0408cd)
1 /*-
2  * Copyright (c) 2011 NetApp, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/systm.h>
35 #include <sys/cpuset.h>
36 
37 #include <machine/cpufunc.h>
38 #include <machine/md_var.h>
39 #include <machine/specialreg.h>
40 
41 #include <machine/vmm.h>
42 
43 #include "x86.h"
44 
45 #define	CPUID_VM_HIGH		0x40000000
46 
47 static const char bhyve_id[12] = "BHyVE BHyVE ";
48 
49 int
50 x86_emulate_cpuid(struct vm *vm, int vcpu_id,
51 		  uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
52 {
53 	int error;
54 	unsigned int 	func, regs[4];
55 	enum x2apic_state x2apic_state;
56 
57 	/*
58 	 * Requests for invalid CPUID levels should map to the highest
59 	 * available level instead.
60 	 */
61 	if (cpu_exthigh != 0 && *eax >= 0x80000000) {
62 		if (*eax > cpu_exthigh)
63 			*eax = cpu_exthigh;
64 	} else if (*eax >= 0x40000000) {
65 		if (*eax > CPUID_VM_HIGH)
66 			*eax = CPUID_VM_HIGH;
67 	} else if (*eax > cpu_high) {
68 		*eax = cpu_high;
69 	}
70 
71 	func = *eax;
72 
73 	/*
74 	 * In general the approach used for CPU topology is to
75 	 * advertise a flat topology where all CPUs are packages with
76 	 * no multi-core or SMT.
77 	 */
78 	switch (func) {
79 		case CPUID_0000_0000:
80 		case CPUID_0000_0002:
81 		case CPUID_0000_0003:
82 		case CPUID_0000_000A:
83 			cpuid_count(*eax, *ecx, regs);
84 			break;
85 
86 		case CPUID_8000_0000:
87 		case CPUID_8000_0001:
88 		case CPUID_8000_0002:
89 		case CPUID_8000_0003:
90 		case CPUID_8000_0004:
91 		case CPUID_8000_0006:
92 		case CPUID_8000_0007:
93 		case CPUID_8000_0008:
94 			cpuid_count(*eax, *ecx, regs);
95 			break;
96 
97 		case CPUID_0000_0001:
98 			do_cpuid(1, regs);
99 
100 			error = vm_get_x2apic_state(vm, vcpu_id, &x2apic_state);
101 			if (error) {
102 				panic("x86_emulate_cpuid: error %d "
103 				      "fetching x2apic state", error);
104 			}
105 
106 			/*
107 			 * Override the APIC ID only in ebx
108 			 */
109 			regs[1] &= ~(CPUID_LOCAL_APIC_ID);
110 			regs[1] |= (vcpu_id << CPUID_0000_0001_APICID_SHIFT);
111 
112 			/*
113 			 * Don't expose VMX, SpeedStep or TME capability.
114 			 * Advertise x2APIC capability and Hypervisor guest.
115 			 */
116 			regs[2] &= ~(CPUID2_VMX | CPUID2_EST | CPUID2_TM2);
117 
118 			regs[2] |= CPUID2_HV;
119 
120 			if (x2apic_state != X2APIC_DISABLED)
121 				regs[2] |= CPUID2_X2APIC;
122 
123 			/*
124 			 * Hide xsave/osxsave/avx until the FPU save/restore
125 			 * issues are resolved
126 			 */
127 			regs[2] &= ~(CPUID2_XSAVE | CPUID2_OSXSAVE |
128 				     CPUID2_AVX);
129 
130 			/*
131 			 * Hide monitor/mwait until we know how to deal with
132 			 * these instructions.
133 			 */
134 			regs[2] &= ~CPUID2_MON;
135 
136 			/*
137 			 * Hide thermal monitoring
138 			 */
139 			regs[3] &= ~(CPUID_ACPI | CPUID_TM);
140 
141 			/*
142 			 * Machine check handling is done in the host.
143 			 * Hide MTRR capability.
144 			 */
145 			regs[3] &= ~(CPUID_MCA | CPUID_MCE | CPUID_MTRR);
146 
147 			/*
148 			 * Disable multi-core.
149 			 */
150 			regs[1] &= ~CPUID_HTT_CORES;
151 			regs[3] &= ~CPUID_HTT;
152 			break;
153 
154 		case CPUID_0000_0004:
155 			do_cpuid(4, regs);
156 
157 			/*
158 			 * Do not expose topology.
159 			 */
160 			regs[0] &= 0xffff8000;
161 			regs[0] |= 0x04008000;
162 			break;
163 
164 		case CPUID_0000_0006:
165 		case CPUID_0000_0007:
166 			/*
167 			 * Handle the access, but report 0 for
168 			 * all options
169 			 */
170 			regs[0] = 0;
171 			regs[1] = 0;
172 			regs[2] = 0;
173 			regs[3] = 0;
174 			break;
175 
176 		case CPUID_0000_000B:
177 			/*
178 			 * Processor topology enumeration
179 			 */
180 			regs[0] = 0;
181 			regs[1] = 0;
182 			regs[2] = *ecx & 0xff;
183 			regs[3] = vcpu_id;
184 			break;
185 
186 		case 0x40000000:
187 			regs[0] = CPUID_VM_HIGH;
188 			bcopy(bhyve_id, &regs[1], 4);
189 			bcopy(bhyve_id, &regs[2], 4);
190 			bcopy(bhyve_id, &regs[3], 4);
191 			break;
192 		default:
193 			/* XXX: Leaf 5? */
194 			return (0);
195 	}
196 
197 	*eax = regs[0];
198 	*ebx = regs[1];
199 	*ecx = regs[2];
200 	*edx = regs[3];
201 	return (1);
202 }
203