KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type

mtrr_for_each_mem_type() is ready now, use it to simplify
kvm_mtrr_get_guest_memory_type()

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index 4c6ac464063e624f353da6b197ac0bb50a4b3eb5..1445c4a03a92c4636d37e05e1de59ea34a3d0af9 100644 (file)
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -600,61 +600,23 @@ static void mtrr_lookup_next(struct mtrr_iter *iter)
 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;
+       struct mtrr_iter iter;
+       u64 start, end;
+       int type = -1;
        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;
+       end = start + PAGE_SIZE;
 
-               if ((start & mask) != (base & mask))
-                       continue;
+       mtrr_for_each_mem_type(&iter, mtrr_state, start, end) {
+               int curr_type = iter.mem_type;
 
                /*
                 * 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;
@@ -694,9 +656,15 @@ u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
                return MTRR_TYPE_WRBACK;
        }
 
-       if (type != -1)
-               return type;
-
-       return mtrr_default_type(mtrr_state);
+       /* It is not covered by MTRRs. */
+       if (iter.partial_map) {
+               /*
+                * We just check one page, partially covered by MTRRs is
+                * impossible.
+                */
+               WARN_ON(type != -1);
+               type = mtrr_default_type(mtrr_state);
+       }
+       return type;
 }
 EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type);