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Diffstat (limited to 'arch/x86/kvm/mtrr.c')
-rw-r--r--arch/x86/kvm/mtrr.c40
1 files changed, 30 insertions, 10 deletions
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index de1d2d8062e2..9e8bf13572e6 100644
--- 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;