blob: 44a316b641db109d99235cfb419d04521143e9fd (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2007-2009 coresystems GmbH
* Copyright (C) 2011 The ChromiumOS Authors. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; version 2 of
* the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <console/console.h>
#include <cpu/x86/msr.h>
#include "common.h"
#define IA32_FEATURE_CONTROL 0x3a
#define CPUID_VMX (1 << 5)
#define CPUID_SMX (1 << 6)
void set_vmx(void)
{
struct cpuid_result regs;
msr_t msr;
int enable = IS_ENABLED(CONFIG_ENABLE_VMX);
int lock = IS_ENABLED(CONFIG_SET_VMX_LOCK_BIT);
regs = cpuid(1);
/* Check that the VMX is supported before reading or writing the MSR. */
if (!((regs.ecx & CPUID_VMX) || (regs.ecx & CPUID_SMX))) {
printk(BIOS_DEBUG, "CPU doesn't support VMX; exiting\n");
return;
}
msr = rdmsr(IA32_FEATURE_CONTROL);
if (msr.lo & (1 << 0)) {
printk(BIOS_ERR, "VMX is locked, so %s will do nothing\n",
__func__);
/* VMX locked. If we set it again we get an illegal
* instruction
*/
return;
}
/* The IA32_FEATURE_CONTROL MSR may initialize with random values.
* It must be cleared regardless of VMX config setting.
*/
msr.hi = msr.lo = 0;
if (enable) {
msr.lo |= (1 << 2);
if (regs.ecx & CPUID_SMX)
msr.lo |= (1 << 1);
}
wrmsr(IA32_FEATURE_CONTROL, msr);
if (lock) {
/* Set lock bit */
msr.lo |= (1 << 0);
wrmsr(IA32_FEATURE_CONTROL, msr);
}
printk(BIOS_DEBUG, "VMX status: %s, %s\n",
enable ? "enabled" : "disabled",
lock ? "locked" : "unlocked");
}
|
