aboutsummaryrefslogtreecommitdiff
path: root/sys/amd64/vmm/amd/svm_msr.c
blob: 088751a167284feefe70104a2b3e585862f83645 (plain) (blame)
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
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*-
 * Copyright (c) 2014, Neel Natu (neel@freebsd.org)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/errno.h>
#include <sys/systm.h>

#include <machine/cpufunc.h>
#include <machine/specialreg.h>
#include <machine/vmm.h>

#include "svm.h"
#include "vmcb.h"
#include "svm_softc.h"
#include "svm_msr.h"

#ifndef MSR_AMDK8_IPM
#define	MSR_AMDK8_IPM	0xc0010055
#endif

enum {
	IDX_MSR_LSTAR,
	IDX_MSR_CSTAR,
	IDX_MSR_STAR,
	IDX_MSR_SF_MASK,
	HOST_MSR_NUM		/* must be the last enumeration */
};

static uint64_t host_msrs[HOST_MSR_NUM];

void
svm_msr_init(void)
{
	/* 
	 * It is safe to cache the values of the following MSRs because they
	 * don't change based on curcpu, curproc or curthread.
	 */
	host_msrs[IDX_MSR_LSTAR] = rdmsr(MSR_LSTAR);
	host_msrs[IDX_MSR_CSTAR] = rdmsr(MSR_CSTAR);
	host_msrs[IDX_MSR_STAR] = rdmsr(MSR_STAR);
	host_msrs[IDX_MSR_SF_MASK] = rdmsr(MSR_SF_MASK);
}

void
svm_msr_guest_init(struct svm_softc *sc, int vcpu)
{
	/*
	 * All the MSRs accessible to the guest are either saved/restored by
	 * hardware on every #VMEXIT/VMRUN (e.g., G_PAT) or are saved/restored
	 * by VMSAVE/VMLOAD (e.g., MSR_GSBASE).
	 *
	 * There are no guest MSRs that are saved/restored "by hand" so nothing
	 * more to do here.
	 */
	return;
}

void
svm_msr_guest_enter(struct svm_softc *sc, int vcpu)
{
	/*
	 * Save host MSRs (if any) and restore guest MSRs (if any).
	 */
}

void
svm_msr_guest_exit(struct svm_softc *sc, int vcpu)
{
	/*
	 * Save guest MSRs (if any) and restore host MSRs.
	 */
	wrmsr(MSR_LSTAR, host_msrs[IDX_MSR_LSTAR]);
	wrmsr(MSR_CSTAR, host_msrs[IDX_MSR_CSTAR]);
	wrmsr(MSR_STAR, host_msrs[IDX_MSR_STAR]);
	wrmsr(MSR_SF_MASK, host_msrs[IDX_MSR_SF_MASK]);

	/* MSR_KGSBASE will be restored on the way back to userspace */
}

int
svm_rdmsr(struct svm_softc *sc, int vcpu, u_int num, uint64_t *result,
    bool *retu)
{
	int error = 0;

	switch (num) {
	case MSR_MCG_CAP:
	case MSR_MCG_STATUS:
		*result = 0;
		break;
	case MSR_MTRRcap:
	case MSR_MTRRdefType:
	case MSR_MTRR4kBase ... MSR_MTRR4kBase + 8:
	case MSR_MTRR16kBase ... MSR_MTRR16kBase + 1:
	case MSR_MTRR64kBase:
	case MSR_SYSCFG:
		*result = 0;
		break;
	case MSR_AMDK8_IPM:
		*result = 0;
		break;
	default:
		error = EINVAL;
		break;
	}

	return (error);
}

int
svm_wrmsr(struct svm_softc *sc, int vcpu, u_int num, uint64_t val, bool *retu)
{
	int error = 0;

	switch (num) {
	case MSR_MCG_CAP:
	case MSR_MCG_STATUS:
		break;		/* ignore writes */
	case MSR_MTRRcap:
		vm_inject_gp(sc->vm, vcpu);
		break;
	case MSR_MTRRdefType:
	case MSR_MTRR4kBase ... MSR_MTRR4kBase + 8:
	case MSR_MTRR16kBase ... MSR_MTRR16kBase + 1:
	case MSR_MTRR64kBase:
	case MSR_SYSCFG:
		break;		/* Ignore writes */
	case MSR_AMDK8_IPM:
		/*
		 * Ignore writes to the "Interrupt Pending Message" MSR.
		 */
		break;
	default:
		error = EINVAL;
		break;
	}

	return (error);
}