freebsd-dev/sys/amd64/vmm/amd/svm_msr.c
Neel Natu 8f02c5e456 IFC r271888.
Restructure MSR emulation so it is all done in processor-specific code.
2014-09-20 21:46:31 +00:00

137 lines
3.4 KiB
C

/*-
* 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/types.h>
#include <sys/errno.h>
#include <machine/cpufunc.h>
#include <machine/specialreg.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_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_AMDK8_IPM:
/*
* Ignore writes to the "Interrupt Pending Message" MSR.
*/
break;
default:
error = EINVAL;
break;
}
return (error);
}