CPUMR0.cpp revision 677833bc953b6cb418c701facbdcf4aa18d6c44e
/** @file
*
* CPUM - Host Context Ring 0.
*/
/*
* Copyright (C) 2006 InnoTek Systemberatung GmbH
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file 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,
* in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
* distribution. VirtualBox OSE is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY of any kind.
*
* If you received this file as part of a commercial VirtualBox
* distribution, then only the terms of your commercial VirtualBox
* license agreement apply instead of the previous paragraph.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#define LOG_GROUP LOG_GROUP_CPUM
#include <VBox/cpum.h>
#include "CPUMInternal.h"
#include <VBox/vm.h>
#include <VBox/x86.h>
#include <VBox/err.h>
#include <VBox/log.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
/**
* Does Ring-0 CPUM initialization.
*
* This is mainly to check that the Host CPU mode is compatible
* with VBox.
*
* @returns VBox status code.
* @param pVM The VM to operate on.
*/
CPUMR0DECL(int) CPUMR0Init(PVM pVM)
{
LogComFlow(("CPUMR0Init: %p\n", pVM));
/*
* Check CR0 & CR4 flags.
*/
uint32_t u32CR0 = ASMGetCR0();
if ((u32CR0 & (X86_CR0_PE | X86_CR0_PG)) != (X86_CR0_PE | X86_CR0_PG)) /* a bit paranoid perhaps.. */
{
LogCom(("CPUMR0Init: PE or PG not set. cr0=%#x\n", u32CR0));
return VERR_UNSUPPORTED_CPU_MODE;
}
/*
* Check for sysenter if it's used.
*/
if (ASMHasCpuId())
{
uint32_t u32CpuVersion;
uint32_t u32Dummy;
uint32_t u32Features;
ASMCpuId(1, &u32CpuVersion, &u32Dummy, &u32Dummy, &u32Features);
uint32_t u32Family = u32CpuVersion >> 8;
uint32_t u32Model = (u32CpuVersion >> 4) & 0xF;
uint32_t u32Stepping = u32CpuVersion & 0xF;
/*
* Intel docs claim you should test both the flag and family, model & stepping.
* Some Pentium Pro cpus have the SEP cpuid flag set, but don't support it.
*/
if ( (u32Features & X86_CPUID_FEATURE_EDX_SEP)
&& !(u32Family == 6 && u32Model < 3 && u32Stepping < 3))
{
/*
* Read the MSR and see if it's in use or not.
*/
uint32_t u32 = ASMRdMsr_Low(MSR_IA32_SYSENTER_CS);
if (u32)
{
pVM->cpum.s.fUseFlags |= CPUM_USE_SYSENTER;
LogCom(("CPUMR0Init: host uses sysenter cs=%08x%08x\n", ASMRdMsr_High(MSR_IA32_SYSENTER_CS), u32));
}
}
/** @todo check for AMD and syscall!!!!!! */
}
/*
* Check if debug registers are armed.
*/
uint32_t u32DR7 = ASMGetDR7();
if (u32DR7 & X86_DR7_ENABLED_MASK)
{
pVM->cpum.s.fUseFlags |= CPUM_USE_DEBUG_REGS_HOST;
LogCom(("CPUMR0Init: host uses debug registers (dr7=%x)\n", u32DR7));
}
return VINF_SUCCESS;
}