2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2014, Neel Natu (neel@freebsd.org)
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include "opt_bhyve_snapshot.h"
34 #include <sys/param.h>
35 #include <sys/errno.h>
36 #include <sys/systm.h>
38 #include <machine/cpufunc.h>
39 #include <machine/specialreg.h>
40 #include <machine/vmm.h>
44 #include "svm_softc.h"
48 #define MSR_AMDK8_IPM 0xc0010055
56 HOST_MSR_NUM /* must be the last enumeration */
59 static uint64_t host_msrs[HOST_MSR_NUM];
65 * It is safe to cache the values of the following MSRs because they
66 * don't change based on curcpu, curproc or curthread.
68 host_msrs[IDX_MSR_LSTAR] = rdmsr(MSR_LSTAR);
69 host_msrs[IDX_MSR_CSTAR] = rdmsr(MSR_CSTAR);
70 host_msrs[IDX_MSR_STAR] = rdmsr(MSR_STAR);
71 host_msrs[IDX_MSR_SF_MASK] = rdmsr(MSR_SF_MASK);
75 svm_msr_guest_init(struct svm_softc *sc, int vcpu)
78 * All the MSRs accessible to the guest are either saved/restored by
79 * hardware on every #VMEXIT/VMRUN (e.g., G_PAT) or are saved/restored
80 * by VMSAVE/VMLOAD (e.g., MSR_GSBASE).
82 * There are no guest MSRs that are saved/restored "by hand" so nothing
89 svm_msr_guest_enter(struct svm_softc *sc, int vcpu)
92 * Save host MSRs (if any) and restore guest MSRs (if any).
97 svm_msr_guest_exit(struct svm_softc *sc, int vcpu)
100 * Save guest MSRs (if any) and restore host MSRs.
102 wrmsr(MSR_LSTAR, host_msrs[IDX_MSR_LSTAR]);
103 wrmsr(MSR_CSTAR, host_msrs[IDX_MSR_CSTAR]);
104 wrmsr(MSR_STAR, host_msrs[IDX_MSR_STAR]);
105 wrmsr(MSR_SF_MASK, host_msrs[IDX_MSR_SF_MASK]);
107 /* MSR_KGSBASE will be restored on the way back to userspace */
111 svm_rdmsr(struct svm_softc *sc, int vcpu, u_int num, uint64_t *result,
122 case MSR_MTRRdefType:
123 case MSR_MTRR4kBase ... MSR_MTRR4kBase + 8:
124 case MSR_MTRR16kBase ... MSR_MTRR16kBase + 1:
125 case MSR_MTRR64kBase:
128 case MSR_EXTFEATURES:
140 svm_wrmsr(struct svm_softc *sc, int vcpu, u_int num, uint64_t val, bool *retu)
147 break; /* ignore writes */
149 vm_inject_gp(sc->vm, vcpu);
151 case MSR_MTRRdefType:
152 case MSR_MTRR4kBase ... MSR_MTRR4kBase + 8:
153 case MSR_MTRR16kBase ... MSR_MTRR16kBase + 1:
154 case MSR_MTRR64kBase:
156 break; /* Ignore writes */
159 * Ignore writes to the "Interrupt Pending Message" MSR.
162 case MSR_K8_UCODE_UPDATE:
164 * Ignore writes to microcode update register.
167 #ifdef BHYVE_SNAPSHOT
169 error = svm_set_tsc_offset(sc, vcpu, val - rdtsc());
172 case MSR_EXTFEATURES: