From 74be52e3e6285fc6e872a2a7baea544106f399ea Mon Sep 17 00:00:00 2001 From: Sheng Yang Date: Thu, 9 Oct 2008 16:01:56 +0800 Subject: [PATCH] KVM: Add local get_mtrr_type() to support MTRR For EPT memory type support. Signed-off-by: Sheng Yang Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 104 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 410ddbc1aa2e..ac2304fd173e 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -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; -- 2.39.5