-/*
- * 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;
-}
-
-u8 kvm_get_guest_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;
-}
-EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type);
-