Merge branch 'fix/rt5645' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...

[deliverable/linux.git] / arch / x86 / kvm / mtrr.c

diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index de1d2d8062e24048232af909d684f0c2ed9e21bc..9e8bf13572e6dc3f95d33d24f079d63e256a3a7a 100644 (file)
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -120,6 +120,16 @@ static u8 mtrr_default_type(struct kvm_mtrr *mtrr_state)
        return mtrr_state->deftype & IA32_MTRR_DEF_TYPE_TYPE_MASK;
 }
 
+static u8 mtrr_disabled_type(void)
+{
+       /*
+        * Intel SDM 11.11.2.2: all MTRRs are disabled when
+        * IA32_MTRR_DEF_TYPE.E bit is cleared, and the UC
+        * memory type is applied to all of physical memory.
+        */
+       return MTRR_TYPE_UNCACHABLE;
+}
+
 /*
 * Three terms are used in the following code:
 * - segment, it indicates the address segments covered by fixed MTRRs.
@@ -434,6 +444,8 @@ struct mtrr_iter {
 
        /* output fields. */
        int mem_type;
+       /* mtrr is completely disabled? */
+       bool mtrr_disabled;
        /* [start, end) is not fully covered in MTRRs? */
        bool partial_map;
 
@@ -549,7 +561,7 @@ static void mtrr_lookup_var_next(struct mtrr_iter *iter)
 static void mtrr_lookup_start(struct mtrr_iter *iter)
 {
        if (!mtrr_is_enabled(iter->mtrr_state)) {
-               iter->partial_map = true;
+               iter->mtrr_disabled = true;
                return;
        }
 
@@ -563,6 +575,7 @@ static void mtrr_lookup_init(struct mtrr_iter *iter,
        iter->mtrr_state = mtrr_state;
        iter->start = start;
        iter->end = end;
+       iter->mtrr_disabled = false;
        iter->partial_map = false;
        iter->fixed = false;
        iter->range = NULL;
@@ -656,15 +669,19 @@ u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
                return MTRR_TYPE_WRBACK;
        }
 
-       /* 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);
-       }
+       if (iter.mtrr_disabled)
+               return mtrr_disabled_type();
+
+       /* not contained in any MTRRs. */
+       if (type == -1)
+               return mtrr_default_type(mtrr_state);
+
+       /*
+        * We just check one page, partially covered by MTRRs is
+        * impossible.
+        */
+       WARN_ON(iter.partial_map);
+
        return type;
 }
 EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type);
@@ -689,6 +706,9 @@ bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn,
                        return false;
        }
 
+       if (iter.mtrr_disabled)
+               return true;
+
        if (!iter.partial_map)
                return true;