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Commit 74be52e3 authored by Sheng Yang's avatar Sheng Yang Committed by Avi Kivity
Browse files

KVM: Add local get_mtrr_type() to support MTRR 



For EPT memory type support.

Signed-off-by: default avatarSheng Yang <sheng@linux.intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 468d472f

arch/x86/kvm/mmu.c

+104 −0
Original line number Diff line number Diff line
@@ -1393,6 +1393,110 @@ struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva) 
	return page;

}



/*

 * The function is based on mtrr_type_lookup() in

 * arch/x86/kernel/cpu/mtrr/generic.c

 */

static int get_mtrr_type(struct mtrr_state_type *mtrr_state,

			 u64 start, u64 end)

{

	int i;

	u64 base, mask;

	u8 prev_match, curr_match;

	int num_var_ranges = KVM_NR_VAR_MTRR;



	if (!mtrr_state->enabled)

		return 0xFF;



	/* Make end inclusive end, instead of exclusive */

	end--;



	/* Look in fixed ranges. Just return the type as per start */

	if (mtrr_state->have_fixed && (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

	 */

	if (!(mtrr_state->enabled & 2))

		return mtrr_state->def_type;



	prev_match = 0xFF;

	for (i = 0; i < num_var_ranges; ++i) {

		unsigned short start_state, end_state;



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

			continue;



		base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +

		       (mtrr_state->var_ranges[i].base_lo & PAGE_MASK);

		mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +

		       (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);



		start_state = ((start & mask) == (base & mask));

		end_state = ((end & mask) == (base & mask));

		if (start_state != end_state)

			return 0xFE;



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

			continue;



		curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;

		if (prev_match == 0xFF) {

			prev_match = curr_match;

			continue;

		}



		if (prev_match == MTRR_TYPE_UNCACHABLE ||

		    curr_match == MTRR_TYPE_UNCACHABLE)

			return MTRR_TYPE_UNCACHABLE;



		if ((prev_match == MTRR_TYPE_WRBACK &&

		     curr_match == MTRR_TYPE_WRTHROUGH) ||

		    (prev_match == MTRR_TYPE_WRTHROUGH &&

		     curr_match == MTRR_TYPE_WRBACK)) {

			prev_match = MTRR_TYPE_WRTHROUGH;

			curr_match = MTRR_TYPE_WRTHROUGH;

		}



		if (prev_match != curr_match)

			return MTRR_TYPE_UNCACHABLE;

	}



	if (prev_match != 0xFF)

		return prev_match;



	return mtrr_state->def_type;

}



static u8 get_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)

{

	u8 mtrr;



	mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,

			     (gfn << PAGE_SHIFT) + PAGE_SIZE);

	if (mtrr == 0xfe || mtrr == 0xff)

		mtrr = MTRR_TYPE_WRBACK;

	return mtrr;

}



static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)

{

	unsigned index;