[linux-2.6-block.git] / arch / x86 / kvm / mtrr.c

/*
 * vMTRR implementation
 *
 * Copyright (C) 2006 Qumranet, Inc.
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 * Copyright(C) 2015 Intel Corporation.
 *
 * Authors:
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *   Avi Kivity   <avi@qumranet.com>
 *   Marcelo Tosatti <mtosatti@redhat.com>
 *   Paolo Bonzini <pbonzini@redhat.com>
 *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 */

#include <linux/kvm_host.h>
#include <asm/mtrr.h>

#include "cpuid.h"
#include "mmu.h"

#define IA32_MTRR_DEF_TYPE_E		(1ULL << 11)
#define IA32_MTRR_DEF_TYPE_FE		(1ULL << 10)
#define IA32_MTRR_DEF_TYPE_TYPE_MASK	(0xff)

static bool msr_mtrr_valid(unsigned msr)
{
	switch (msr) {
	case 0x200 ... 0x200 + 2 * KVM_NR_VAR_MTRR - 1:
	case MSR_MTRRfix64K_00000:
	case MSR_MTRRfix16K_80000:
	case MSR_MTRRfix16K_A0000:
	case MSR_MTRRfix4K_C0000:
	case MSR_MTRRfix4K_C8000:
	case MSR_MTRRfix4K_D0000:
	case MSR_MTRRfix4K_D8000:
	case MSR_MTRRfix4K_E0000:
	case MSR_MTRRfix4K_E8000:
	case MSR_MTRRfix4K_F0000:
	case MSR_MTRRfix4K_F8000:
	case MSR_MTRRdefType:
	case MSR_IA32_CR_PAT:
		return true;
	case 0x2f8:
		return true;
	}
	return false;
}

static bool valid_pat_type(unsigned t)
{
	return t < 8 && (1 << t) & 0xf3; /* 0, 1, 4, 5, 6, 7 */
}

static bool valid_mtrr_type(unsigned t)
{
	return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */
}

bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
	int i;
	u64 mask;

	if (!msr_mtrr_valid(msr))
		return false;

	if (msr == MSR_IA32_CR_PAT) {
		for (i = 0; i < 8; i++)
			if (!valid_pat_type((data >> (i * 8)) & 0xff))
				return false;
		return true;
	} else if (msr == MSR_MTRRdefType) {
		if (data & ~0xcff)
			return false;
		return valid_mtrr_type(data & 0xff);
	} else if (msr >= MSR_MTRRfix64K_00000 && msr <= MSR_MTRRfix4K_F8000) {
		for (i = 0; i < 8 ; i++)
			if (!valid_mtrr_type((data >> (i * 8)) & 0xff))
				return false;
		return true;
	}

	/* variable MTRRs */
	WARN_ON(!(msr >= 0x200 && msr < 0x200 + 2 * KVM_NR_VAR_MTRR));

	mask = (~0ULL) << cpuid_maxphyaddr(vcpu);
	if ((msr & 1) == 0) {
		/* MTRR base */
		if (!valid_mtrr_type(data & 0xff))
			return false;
		mask |= 0xf00;
	} else
		/* MTRR mask */
		mask |= 0x7ff;
	if (data & mask) {
		kvm_inject_gp(vcpu, 0);
		return false;
	}

	return true;
}
EXPORT_SYMBOL_GPL(kvm_mtrr_valid);

static bool mtrr_is_enabled(struct kvm_mtrr *mtrr_state)
{
	return !!(mtrr_state->deftype & IA32_MTRR_DEF_TYPE_E);
}

static bool fixed_mtrr_is_enabled(struct kvm_mtrr *mtrr_state)
{
	return !!(mtrr_state->deftype & IA32_MTRR_DEF_TYPE_FE);
}

static u8 mtrr_default_type(struct kvm_mtrr *mtrr_state)
{
	return mtrr_state->deftype & IA32_MTRR_DEF_TYPE_TYPE_MASK;
}

/*
* Three terms are used in the following code:
* - segment, it indicates the address segments covered by fixed MTRRs.
* - unit, it corresponds to the MSR entry in the segment.
* - range, a range is covered in one memory cache type.
*/
struct fixed_mtrr_segment {
	u64 start;
	u64 end;

	int range_shift;

	/* the start position in kvm_mtrr.fixed_ranges[]. */
	int range_start;
};

static struct fixed_mtrr_segment fixed_seg_table[] = {
	/* MSR_MTRRfix64K_00000, 1 unit. 64K fixed mtrr. */
	{
		.start = 0x0,
		.end = 0x80000,
		.range_shift = 16, /* 64K */
		.range_start = 0,
	},

	/*
	 * MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000, 2 units,
	 * 16K fixed mtrr.
	 */
	{
		.start = 0x80000,
		.end = 0xc0000,
		.range_shift = 14, /* 16K */
		.range_start = 8,
	},

	/*
	 * MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000, 8 units,
	 * 4K fixed mtrr.
	 */
	{
		.start = 0xc0000,
		.end = 0x100000,
		.range_shift = 12, /* 12K */
		.range_start = 24,
	}
};

/*
 * The size of unit is covered in one MSR, one MSR entry contains
 * 8 ranges so that unit size is always 8 * 2^range_shift.
 */
static u64 fixed_mtrr_seg_unit_size(int seg)
{
	return 8 << fixed_seg_table[seg].range_shift;
}

static bool fixed_msr_to_seg_unit(u32 msr, int *seg, int *unit)
{
	switch (msr) {
	case MSR_MTRRfix64K_00000:
		*seg = 0;
		*unit = 0;
		break;
	case MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000:
		*seg = 1;
		*unit = msr - MSR_MTRRfix16K_80000;
		break;
	case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000:
		*seg = 2;
		*unit = msr - MSR_MTRRfix4K_C0000;
		break;
	default:
		return false;
	}

	return true;
}

static void fixed_mtrr_seg_unit_range(int seg, int unit, u64 *start, u64 *end)
{
	struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
	u64 unit_size = fixed_mtrr_seg_unit_size(seg);

	*start = mtrr_seg->start + unit * unit_size;
	*end = *start + unit_size;
	WARN_ON(*end > mtrr_seg->end);
}

static int fixed_mtrr_seg_unit_range_index(int seg, int unit)
{
	struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];

	WARN_ON(mtrr_seg->start + unit * fixed_mtrr_seg_unit_size(seg)
		> mtrr_seg->end);

	/* each unit has 8 ranges. */
	return mtrr_seg->range_start + 8 * unit;
}

static bool fixed_msr_to_range(u32 msr, u64 *start, u64 *end)
{
	int seg, unit;

	if (!fixed_msr_to_seg_unit(msr, &seg, &unit))
		return false;

	fixed_mtrr_seg_unit_range(seg, unit, start, end);
	return true;
}

static int fixed_msr_to_range_index(u32 msr)
{
	int seg, unit;

	if (!fixed_msr_to_seg_unit(msr, &seg, &unit))
		return -1;

	return fixed_mtrr_seg_unit_range_index(seg, unit);
}

static void var_mtrr_range(struct kvm_mtrr_range *range, u64 *start, u64 *end)
{
	u64 mask;

	*start = range->base & PAGE_MASK;

	mask = range->mask & PAGE_MASK;
	mask |= ~0ULL << boot_cpu_data.x86_phys_bits;

	/* This cannot overflow because writing to the reserved bits of
	 * variable MTRRs causes a #GP.
	 */
	*end = (*start | ~mask) + 1;
}

static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
{
	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
	gfn_t start, end;
	int index;

	if (msr == MSR_IA32_CR_PAT || !tdp_enabled ||
	      !kvm_arch_has_noncoherent_dma(vcpu->kvm))
		return;

	if (!mtrr_is_enabled(mtrr_state) && msr != MSR_MTRRdefType)
		return;

	/* fixed MTRRs. */
	if (fixed_msr_to_range(msr, &start, &end)) {
		if (!fixed_mtrr_is_enabled(mtrr_state))
			return;
	} else if (msr == MSR_MTRRdefType) {
		start = 0x0;
		end = ~0ULL;
	} else {
		/* variable range MTRRs. */
		index = (msr - 0x200) / 2;
		var_mtrr_range(&mtrr_state->var_ranges[index], &start, &end);
	}

	kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
}

int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
	int index;

	if (!kvm_mtrr_valid(vcpu, msr, data))
		return 1;

	index = fixed_msr_to_range_index(msr);
	if (index >= 0)
		*(u64 *)&vcpu->arch.mtrr_state.fixed_ranges[index] = data;
	else if (msr == MSR_MTRRdefType)
		vcpu->arch.mtrr_state.deftype = data;
	else if (msr == MSR_IA32_CR_PAT)
		vcpu->arch.pat = data;
	else {	/* Variable MTRRs */
		int is_mtrr_mask;

		index = (msr - 0x200) / 2;
		is_mtrr_mask = msr - 0x200 - 2 * index;
		if (!is_mtrr_mask)
			vcpu->arch.mtrr_state.var_ranges[index].base = data;
		else
			vcpu->arch.mtrr_state.var_ranges[index].mask = data;
	}

	update_mtrr(vcpu, msr);
	return 0;
}

int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
	int index;

	/* MSR_MTRRcap is a readonly MSR. */
	if (msr == MSR_MTRRcap) {
		/*
		 * SMRR = 0
		 * WC = 1
		 * FIX = 1
		 * VCNT = KVM_NR_VAR_MTRR
		 */
		*pdata = 0x500 | KVM_NR_VAR_MTRR;
		return 0;
	}

	if (!msr_mtrr_valid(msr))
		return 1;

	index = fixed_msr_to_range_index(msr);
	if (index >= 0)
		*pdata = *(u64 *)&vcpu->arch.mtrr_state.fixed_ranges[index];
	else if (msr == MSR_MTRRdefType)
		*pdata = vcpu->arch.mtrr_state.deftype;
	else if (msr == MSR_IA32_CR_PAT)
		*pdata = vcpu->arch.pat;
	else {	/* Variable MTRRs */
		int is_mtrr_mask;

		index = (msr - 0x200) / 2;
		is_mtrr_mask = msr - 0x200 - 2 * index;
		if (!is_mtrr_mask)
			*pdata = vcpu->arch.mtrr_state.var_ranges[index].base;
		else
			*pdata = vcpu->arch.mtrr_state.var_ranges[index].mask;
	}

	return 0;
}

u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
{
	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
	u64 base, mask, start;
	int i, num_var_ranges, type;
	const int wt_wb_mask = (1 << MTRR_TYPE_WRBACK)
			       | (1 << MTRR_TYPE_WRTHROUGH);

	start = gfn_to_gpa(gfn);
	num_var_ranges = KVM_NR_VAR_MTRR;
	type = -1;

	/* MTRR is completely disabled, use UC for all of physical memory. */
	if (!mtrr_is_enabled(mtrr_state))
		return MTRR_TYPE_UNCACHABLE;

	/* Look in fixed ranges. Just return the type as per start */
	if (fixed_mtrr_is_enabled(mtrr_state) && (start < 0x100000)) {
		int idx;

		if (start < 0x80000) {
			idx = 0;
			idx += (start >> 16);
			return mtrr_state->fixed_ranges[idx];
		} else if (start < 0xC0000) {
			idx = 1 * 8;
			idx += ((start - 0x80000) >> 14);
			return mtrr_state->fixed_ranges[idx];
		} else if (start < 0x1000000) {
			idx = 3 * 8;
			idx += ((start - 0xC0000) >> 12);
			return mtrr_state->fixed_ranges[idx];
		}
	}

	/*
	 * Look in variable ranges
	 * Look of multiple ranges matching this address and pick type
	 * as per MTRR precedence
	 */
	for (i = 0; i < num_var_ranges; ++i) {
		int curr_type;

		if (!(mtrr_state->var_ranges[i].mask & (1 << 11)))
			continue;

		base = mtrr_state->var_ranges[i].base & PAGE_MASK;
		mask = mtrr_state->var_ranges[i].mask & PAGE_MASK;

		if ((start & mask) != (base & mask))
			continue;

		/*
		 * Please refer to Intel SDM Volume 3: 11.11.4.1 MTRR
		 * Precedences.
		 */

		curr_type = mtrr_state->var_ranges[i].base & 0xff;
		if (type == -1) {
			type = curr_type;
			continue;
		}

		/*
		 * If two or more variable memory ranges match and the
		 * memory types are identical, then that memory type is
		 * used.
		 */
		if (type == curr_type)
			continue;

		/*
		 * If two or more variable memory ranges match and one of
		 * the memory types is UC, the UC memory type used.
		 */
		if (curr_type == MTRR_TYPE_UNCACHABLE)
			return MTRR_TYPE_UNCACHABLE;

		/*
		 * If two or more variable memory ranges match and the
		 * memory types are WT and WB, the WT memory type is used.
		 */
		if (((1 << type) & wt_wb_mask) &&
		      ((1 << curr_type) & wt_wb_mask)) {
			type = MTRR_TYPE_WRTHROUGH;
			continue;
		}

		/*
		 * For overlaps not defined by the above rules, processor
		 * behavior is undefined.
		 */

		/* We use WB for this undefined behavior. :( */
		return MTRR_TYPE_WRBACK;
	}

	if (type != -1)
		return type;

	return mtrr_default_type(mtrr_state);
}
EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type);
Commit	Line	Data
ff53604b XG	1	/*
	2	* vMTRR implementation
	3	*
	4	* Copyright (C) 2006 Qumranet, Inc.
	5	* Copyright 2010 Red Hat, Inc. and/or its affiliates.
	6	* Copyright(C) 2015 Intel Corporation.
	7	*
	8	* Authors:
	9	* Yaniv Kamay <yaniv@qumranet.com>
	10	* Avi Kivity <avi@qumranet.com>
	11	* Marcelo Tosatti <mtosatti@redhat.com>
	12	* Paolo Bonzini <pbonzini@redhat.com>
	13	* Xiao Guangrong <guangrong.xiao@linux.intel.com>
	14	*
	15	* This work is licensed under the terms of the GNU GPL, version 2. See
	16	* the COPYING file in the top-level directory.
	17	*/
	18
	19	#include <linux/kvm_host.h>
	20	#include <asm/mtrr.h>
	21
	22	#include "cpuid.h"
	23	#include "mmu.h"
	24
10fac2dc XG	25	#define IA32_MTRR_DEF_TYPE_E (1ULL << 11)
	26	#define IA32_MTRR_DEF_TYPE_FE (1ULL << 10)
	27	#define IA32_MTRR_DEF_TYPE_TYPE_MASK (0xff)
	28
ff53604b XG	29	static bool msr_mtrr_valid(unsigned msr)
	30	{
	31	switch (msr) {
	32	case 0x200 ... 0x200 + 2 * KVM_NR_VAR_MTRR - 1:
	33	case MSR_MTRRfix64K_00000:
	34	case MSR_MTRRfix16K_80000:
	35	case MSR_MTRRfix16K_A0000:
	36	case MSR_MTRRfix4K_C0000:
	37	case MSR_MTRRfix4K_C8000:
	38	case MSR_MTRRfix4K_D0000:
	39	case MSR_MTRRfix4K_D8000:
	40	case MSR_MTRRfix4K_E0000:
	41	case MSR_MTRRfix4K_E8000:
	42	case MSR_MTRRfix4K_F0000:
	43	case MSR_MTRRfix4K_F8000:
	44	case MSR_MTRRdefType:
	45	case MSR_IA32_CR_PAT:
	46	return true;
	47	case 0x2f8:
	48	return true;
	49	}
	50	return false;
	51	}
	52
	53	static bool valid_pat_type(unsigned t)
	54	{
	55	return t < 8 && (1 << t) & 0xf3; /* 0, 1, 4, 5, 6, 7 */
	56	}
	57
	58	static bool valid_mtrr_type(unsigned t)
	59	{
	60	return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */
	61	}
	62
	63	bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data)
	64	{
	65	int i;
	66	u64 mask;
	67
	68	if (!msr_mtrr_valid(msr))
	69	return false;
	70
	71	if (msr == MSR_IA32_CR_PAT) {
	72	for (i = 0; i < 8; i++)
	73	if (!valid_pat_type((data >> (i * 8)) & 0xff))
	74	return false;
	75	return true;
	76	} else if (msr == MSR_MTRRdefType) {
	77	if (data & ~0xcff)
	78	return false;
	79	return valid_mtrr_type(data & 0xff);
	80	} else if (msr >= MSR_MTRRfix64K_00000 && msr <= MSR_MTRRfix4K_F8000) {
	81	for (i = 0; i < 8 ; i++)
	82	if (!valid_mtrr_type((data >> (i * 8)) & 0xff))
	83	return false;
	84	return true;
	85	}
	86
	87	/* variable MTRRs */
	88	WARN_ON(!(msr >= 0x200 && msr < 0x200 + 2 * KVM_NR_VAR_MTRR));
	89
	90	mask = (~0ULL) << cpuid_maxphyaddr(vcpu);
	91	if ((msr & 1) == 0) {
	92	/* MTRR base */
93	if (!valid_mtrr_type(data & 0xff))
94	return false;
95	mask \|= 0xf00;
96	} else
97	/* MTRR mask */
98	mask \|= 0x7ff;
99	if (data & mask) {
100	kvm_inject_gp(vcpu, 0);
101	return false;
102	}
103
104	return true;
105	}
106	EXPORT_SYMBOL_GPL(kvm_mtrr_valid);
107
10fac2dc XG	108	static bool mtrr_is_enabled(struct kvm_mtrr *mtrr_state)
	109	{
	110	return !!(mtrr_state->deftype & IA32_MTRR_DEF_TYPE_E);
	111	}
	112
	113	static bool fixed_mtrr_is_enabled(struct kvm_mtrr *mtrr_state)
	114	{
	115	return !!(mtrr_state->deftype & IA32_MTRR_DEF_TYPE_FE);
	116	}
	117
	118	static u8 mtrr_default_type(struct kvm_mtrr *mtrr_state)
	119	{
	120	return mtrr_state->deftype & IA32_MTRR_DEF_TYPE_TYPE_MASK;
	121	}
	122
de9aef5e XG	123	/*
	124	* Three terms are used in the following code:
	125	* - segment, it indicates the address segments covered by fixed MTRRs.
	126	* - unit, it corresponds to the MSR entry in the segment.
	127	* - range, a range is covered in one memory cache type.
	128	*/
	129	struct fixed_mtrr_segment {
	130	u64 start;
	131	u64 end;
	132
	133	int range_shift;
	134
	135	/* the start position in kvm_mtrr.fixed_ranges[]. */
	136	int range_start;
	137	};
	138
	139	static struct fixed_mtrr_segment fixed_seg_table[] = {
	140	/* MSR_MTRRfix64K_00000, 1 unit. 64K fixed mtrr. */
	141	{
	142	.start = 0x0,
	143	.end = 0x80000,
	144	.range_shift = 16, /* 64K */
	145	.range_start = 0,
	146	},
	147
	148	/*
	149	* MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000, 2 units,
	150	* 16K fixed mtrr.
	151	*/
	152	{
	153	.start = 0x80000,
	154	.end = 0xc0000,
	155	.range_shift = 14, /* 16K */
	156	.range_start = 8,
	157	},
	158
	159	/*
	160	* MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000, 8 units,
	161	* 4K fixed mtrr.
	162	*/
	163	{
	164	.start = 0xc0000,
	165	.end = 0x100000,
	166	.range_shift = 12, /* 12K */
	167	.range_start = 24,
	168	}
	169	};
	170
	171	/*
	172	* The size of unit is covered in one MSR, one MSR entry contains
	173	* 8 ranges so that unit size is always 8 * 2^range_shift.
	174	*/
	175	static u64 fixed_mtrr_seg_unit_size(int seg)
	176	{
	177	return 8 << fixed_seg_table[seg].range_shift;
	178	}
	179
	180	static bool fixed_msr_to_seg_unit(u32 msr, int seg, int unit)
	181	{
	182	switch (msr) {
	183	case MSR_MTRRfix64K_00000:
	184	*seg = 0;
	185	*unit = 0;
	186	break;
187	case MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000:
188	*seg = 1;
189	*unit = msr - MSR_MTRRfix16K_80000;
190	break;
191	case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000:
192	*seg = 2;
193	*unit = msr - MSR_MTRRfix4K_C0000;
194	break;
195	default:
196	return false;
197	}
198
199	return true;
200	}
201
202	static void fixed_mtrr_seg_unit_range(int seg, int unit, u64 start, u64 end)
203	{
204	struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
205	u64 unit_size = fixed_mtrr_seg_unit_size(seg);
206
207	start = mtrr_seg->start + unit unit_size;
208	end = start + unit_size;
209	WARN_ON(*end > mtrr_seg->end);
210	}
211
212	static int fixed_mtrr_seg_unit_range_index(int seg, int unit)
213	{
214	struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
215
216	WARN_ON(mtrr_seg->start + unit * fixed_mtrr_seg_unit_size(seg)
217	> mtrr_seg->end);
218
219	/* each unit has 8 ranges. */
220	return mtrr_seg->range_start + 8 * unit;
221	}
222
223	static bool fixed_msr_to_range(u32 msr, u64 start, u64 end)
224	{
225	int seg, unit;
226
227	if (!fixed_msr_to_seg_unit(msr, &seg, &unit))
228	return false;
229
230	fixed_mtrr_seg_unit_range(seg, unit, start, end);
231	return true;
232	}
233
234	static int fixed_msr_to_range_index(u32 msr)
235	{
236	int seg, unit;
237
238	if (!fixed_msr_to_seg_unit(msr, &seg, &unit))
239	return -1;
240
241	return fixed_mtrr_seg_unit_range_index(seg, unit);
242	}
243
a13842dc XG	244	static void var_mtrr_range(struct kvm_mtrr_range range, u64 start, u64 *end)
	245	{
	246	u64 mask;
	247
	248	*start = range->base & PAGE_MASK;
	249
	250	mask = range->mask & PAGE_MASK;
	251	mask \|= ~0ULL << boot_cpu_data.x86_phys_bits;
	252
	253	/* This cannot overflow because writing to the reserved bits of
	254	* variable MTRRs causes a #GP.
	255	*/
	256	end = (start \| ~mask) + 1;
	257	}
	258
ff53604b XG	259	static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
ff53604b XG	260	{
70109e7d	261	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
a13842dc	262	gfn_t start, end;
ff53604b	263	int index;
ff53604b XG	264
	265	if (msr == MSR_IA32_CR_PAT \|\| !tdp_enabled \|\|
	266	!kvm_arch_has_noncoherent_dma(vcpu->kvm))
	267	return;
	268
10fac2dc	269	if (!mtrr_is_enabled(mtrr_state) && msr != MSR_MTRRdefType)
ff53604b XG	270	return;
ff53604b XG	271
de9aef5e XG	272	/* fixed MTRRs. */
	273	if (fixed_msr_to_range(msr, &start, &end)) {
	274	if (!fixed_mtrr_is_enabled(mtrr_state))
	275	return;
	276	} else if (msr == MSR_MTRRdefType) {
ff53604b XG	277	start = 0x0;
ff53604b XG	278	end = ~0ULL;
de9aef5e	279	} else {
ff53604b	280	/* variable range MTRRs. */
ff53604b	281	index = (msr - 0x200) / 2;
a13842dc	282	var_mtrr_range(&mtrr_state->var_ranges[index], &start, &end);
ff53604b XG	283	}
ff53604b XG	284
ff53604b XG	285	kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
	286	}
	287
	288	int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
	289	{
de9aef5e	290	int index;
ff53604b XG	291
	292	if (!kvm_mtrr_valid(vcpu, msr, data))
	293	return 1;
	294
de9aef5e XG	295	index = fixed_msr_to_range_index(msr);
	296	if (index >= 0)
	297	(u64 )&vcpu->arch.mtrr_state.fixed_ranges[index] = data;
	298	else if (msr == MSR_MTRRdefType)
10fac2dc	299	vcpu->arch.mtrr_state.deftype = data;
ff53604b XG	300	else if (msr == MSR_IA32_CR_PAT)
	301	vcpu->arch.pat = data;
	302	else { /* Variable MTRRs */
de9aef5e	303	int is_mtrr_mask;
ff53604b	304
de9aef5e XG	305	index = (msr - 0x200) / 2;
de9aef5e XG	306	is_mtrr_mask = msr - 0x200 - 2 * index;
ff53604b	307	if (!is_mtrr_mask)
de9aef5e	308	vcpu->arch.mtrr_state.var_ranges[index].base = data;
ff53604b	309	else
de9aef5e	310	vcpu->arch.mtrr_state.var_ranges[index].mask = data;
ff53604b XG	311	}
	312
	313	update_mtrr(vcpu, msr);
	314	return 0;
	315	}
	316
	317	int kvm_mtrr_get_msr(struct kvm_vcpu vcpu, u32 msr, u64 pdata)
	318	{
de9aef5e	319	int index;
ff53604b	320
eb839917 XG	321	/* MSR_MTRRcap is a readonly MSR. */
	322	if (msr == MSR_MTRRcap) {
	323	/*
	324	* SMRR = 0
	325	* WC = 1
	326	* FIX = 1
	327	* VCNT = KVM_NR_VAR_MTRR
	328	*/
	329	*pdata = 0x500 \| KVM_NR_VAR_MTRR;
	330	return 0;
	331	}
	332
ff53604b XG	333	if (!msr_mtrr_valid(msr))
	334	return 1;
	335
de9aef5e XG	336	index = fixed_msr_to_range_index(msr);
	337	if (index >= 0)
	338	pdata = (u64 *)&vcpu->arch.mtrr_state.fixed_ranges[index];
	339	else if (msr == MSR_MTRRdefType)
10fac2dc	340	*pdata = vcpu->arch.mtrr_state.deftype;
ff53604b XG	341	else if (msr == MSR_IA32_CR_PAT)
	342	*pdata = vcpu->arch.pat;
	343	else { /* Variable MTRRs */
de9aef5e	344	int is_mtrr_mask;
ff53604b	345
de9aef5e XG	346	index = (msr - 0x200) / 2;
de9aef5e XG	347	is_mtrr_mask = msr - 0x200 - 2 * index;
ff53604b	348	if (!is_mtrr_mask)
de9aef5e	349	*pdata = vcpu->arch.mtrr_state.var_ranges[index].base;
ff53604b	350	else
de9aef5e	351	*pdata = vcpu->arch.mtrr_state.var_ranges[index].mask;
ff53604b XG	352	}
	353
	354	return 0;
	355	}
	356
3f3f78b6	357	u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
ff53604b	358	{
3f3f78b6 XG	359	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
	360	u64 base, mask, start;
	361	int i, num_var_ranges, type;
	362	const int wt_wb_mask = (1 << MTRR_TYPE_WRBACK)
	363	\| (1 << MTRR_TYPE_WRTHROUGH);
	364
	365	start = gfn_to_gpa(gfn);
	366	num_var_ranges = KVM_NR_VAR_MTRR;
	367	type = -1;
ff53604b XG	368
ff53604b XG	369	/* MTRR is completely disabled, use UC for all of physical memory. */
10fac2dc	370	if (!mtrr_is_enabled(mtrr_state))
ff53604b XG	371	return MTRR_TYPE_UNCACHABLE;
ff53604b XG	372
ff53604b	373	/* Look in fixed ranges. Just return the type as per start */
10fac2dc	374	if (fixed_mtrr_is_enabled(mtrr_state) && (start < 0x100000)) {
ff53604b XG	375	int idx;
	376
	377	if (start < 0x80000) {
	378	idx = 0;
	379	idx += (start >> 16);
	380	return mtrr_state->fixed_ranges[idx];
	381	} else if (start < 0xC0000) {
	382	idx = 1 * 8;
	383	idx += ((start - 0x80000) >> 14);
	384	return mtrr_state->fixed_ranges[idx];
	385	} else if (start < 0x1000000) {
	386	idx = 3 * 8;
	387	idx += ((start - 0xC0000) >> 12);
	388	return mtrr_state->fixed_ranges[idx];
	389	}
	390	}
	391
	392	/*
	393	* Look in variable ranges
	394	* Look of multiple ranges matching this address and pick type
	395	* as per MTRR precedence
	396	*/
ff53604b	397	for (i = 0; i < num_var_ranges; ++i) {
3f3f78b6	398	int curr_type;
ff53604b	399
86fd5270	400	if (!(mtrr_state->var_ranges[i].mask & (1 << 11)))
ff53604b XG	401	continue;
ff53604b XG	402
86fd5270 XG	403	base = mtrr_state->var_ranges[i].base & PAGE_MASK;
86fd5270 XG	404	mask = mtrr_state->var_ranges[i].mask & PAGE_MASK;
ff53604b	405
ff53604b XG	406	if ((start & mask) != (base & mask))
	407	continue;
	408
3f3f78b6 XG	409	/*
	410	* Please refer to Intel SDM Volume 3: 11.11.4.1 MTRR
	411	* Precedences.
	412	*/
	413
	414	curr_type = mtrr_state->var_ranges[i].base & 0xff;
	415	if (type == -1) {
	416	type = curr_type;
ff53604b XG	417	continue;
	418	}
	419
3f3f78b6 XG	420	/*
	421	* If two or more variable memory ranges match and the
	422	* memory types are identical, then that memory type is
	423	* used.
	424	*/
	425	if (type == curr_type)
	426	continue;
	427
	428	/*
	429	* If two or more variable memory ranges match and one of
	430	* the memory types is UC, the UC memory type used.
	431	*/
	432	if (curr_type == MTRR_TYPE_UNCACHABLE)
ff53604b XG	433	return MTRR_TYPE_UNCACHABLE;
ff53604b XG	434
3f3f78b6 XG	435	/*
	436	* If two or more variable memory ranges match and the
	437	* memory types are WT and WB, the WT memory type is used.
	438	*/
	439	if (((1 << type) & wt_wb_mask) &&
	440	((1 << curr_type) & wt_wb_mask)) {
	441	type = MTRR_TYPE_WRTHROUGH;
	442	continue;
ff53604b XG	443	}
ff53604b XG	444
3f3f78b6 XG	445	/*
	446	* For overlaps not defined by the above rules, processor
	447	* behavior is undefined.
	448	*/
	449
	450	/* We use WB for this undefined behavior. :( */
	451	return MTRR_TYPE_WRBACK;
ff53604b XG	452	}
ff53604b XG	453
3f3f78b6 XG	454	if (type != -1)
3f3f78b6 XG	455	return type;
ff53604b	456
10fac2dc	457	return mtrr_default_type(mtrr_state);
ff53604b	458	}
ff53604b	459	EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type);