It walks all MTRRs and gets all the memory cache type setting for the
specified range also it checks if the range is fully covered by MTRRs
Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/mtrr.c | 188 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 188 insertions(+)
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index e5e16a1..10f0148 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -220,6 +220,15 @@ static int fixed_mtrr_seg_unit_range_index(int seg, int unit)
return mtrr_seg->range_start + 8 * unit;
}
+static int fixed_mtrr_seg_end_range_index(int seg)
+{
+ struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
+ int n;
+
+ n = (mtrr_seg->end - mtrr_seg->start) / mtrr_seg->range_size;
+ return mtrr_seg->range_start + n - 1;
+}
+
static bool fixed_msr_to_range(u32 msr, u64 *start, u64 *end)
{
int seg, unit;
@@ -266,6 +275,14 @@ static int fixed_mtrr_addr_seg_to_range_index(u64 addr, int seg)
return index;
}
+static u64 fixed_mtrr_range_end_addr(int seg, int index)
+{
+ struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
+ int pos = index - mtrr_seg->range_start;
+
+ return mtrr_seg->start + mtrr_seg->range_size * (pos + 1);
+}
+
static void var_mtrr_range(struct kvm_mtrr_range *range, u64 *start, u64 *end)
{
u64 mask;
@@ -418,6 +435,177 @@ void kvm_vcpu_mtrr_init(struct kvm_vcpu *vcpu)
INIT_LIST_HEAD(&vcpu->arch.mtrr_state.head);
}
+struct mtrr_iter {
+ /* input fields. */
+ struct kvm_mtrr *mtrr_state;
+ u64 start;
+ u64 end;
+
+ /* output fields. */
+ int mem_type;
+ /* [start, end) is not fully covered in MTRRs? */
+ bool partial_map;
+
+ /* private fields. */
+ union {
+ /* used for fixed MTRRs. */
+ struct {
+ int index;
+ int seg;
+ };
+
+ /* used for var MTRRs. */
+ struct {
+ struct kvm_mtrr_range *range;
+ /* max address has been covered in var MTRRs. */
+ u64 start_max;
+ };
+ };
+
+ bool fixed;
+};
+
+static bool mtrr_lookup_fixed_start(struct mtrr_iter *iter)
+{
+ int seg, index;
+
+ if (!fixed_mtrr_is_enabled(iter->mtrr_state))
+ return false;
+
+ seg = fixed_mtrr_addr_to_seg(iter->start);
+ if (seg < 0)
+ return false;
+
+ iter->fixed = true;
+ index = fixed_mtrr_addr_seg_to_range_index(iter->start, seg);
+ iter->index = index;
+ iter->seg = seg;
+ return true;
+}
+
+static bool match_var_range(struct mtrr_iter *iter,
+ struct kvm_mtrr_range *range)
+{
+ u64 start, end;
+
+ var_mtrr_range(range, &start, &end);
+ if (!(start >= iter->end || end <= iter->start)) {
+ iter->range = range;
+
+ /*
+ * the function is called when we do kvm_mtrr.head walking.
+ * Range has the minimum base address which interleaves
+ * [looker->start_max, looker->end).
+ */
+ iter->partial_map |= iter->start_max < start;
+
+ /* update the max address has been covered. */
+ iter->start_max = max(iter->start_max, end);
+ return true;
+ }
+
+ return false;
+}
+
+static void __mtrr_lookup_var_next(struct mtrr_iter *iter)
+{
+ struct kvm_mtrr *mtrr_state = iter->mtrr_state;
+
+ list_for_each_entry_continue(iter->range, &mtrr_state->head, node)
+ if (match_var_range(iter, iter->range))
+ return;
+
+ iter->range = NULL;
+ iter->partial_map |= iter->start_max < iter->end;
+}
+
+static void mtrr_lookup_var_start(struct mtrr_iter *iter)
+{
+ struct kvm_mtrr *mtrr_state = iter->mtrr_state;
+
+ iter->fixed = false;
+ iter->start_max = iter->start;
+ iter->range = list_prepare_entry(iter->range, &mtrr_state->head, node);
+
+ __mtrr_lookup_var_next(iter);
+}
+
+static void mtrr_lookup_fixed_next(struct mtrr_iter *iter)
+{
+ /* terminate the lookup. */
+ if (fixed_mtrr_range_end_addr(iter->seg, iter->index) >= iter->end) {
+ iter->fixed = false;
+ iter->range = NULL;
+ return;
+ }
+
+ iter->index++;
+
+ /* have looked up for all fixed MTRRs. */
+ if (iter->index >= ARRAY_SIZE(iter->mtrr_state->fixed_ranges))
+ return mtrr_lookup_var_start(iter);
+
+ /* switch to next segment. */
+ if (iter->index > fixed_mtrr_seg_end_range_index(iter->seg))
+ iter->seg++;
+}
+
+static void mtrr_lookup_var_next(struct mtrr_iter *iter)
+{
+ __mtrr_lookup_var_next(iter);
+}
+
+static void mtrr_lookup_start(struct mtrr_iter *iter)
+{
+ if (!mtrr_is_enabled(iter->mtrr_state)) {
+ iter->partial_map = true;
+ return;
+ }
+
+ if (!mtrr_lookup_fixed_start(iter))
+ mtrr_lookup_var_start(iter);
+}
+
+static void mtrr_lookup_init(struct mtrr_iter *iter,
+ struct kvm_mtrr *mtrr_state, u64 start, u64 end)
+{
+ iter->mtrr_state = mtrr_state;
+ iter->start = start;
+ iter->end = end;
+ iter->partial_map = false;
+ iter->fixed = false;
+ iter->range = NULL;
+
+ mtrr_lookup_start(iter);
+}
+
+static bool mtrr_lookup_okay(struct mtrr_iter *iter)
+{
+ if (iter->fixed) {
+ iter->mem_type = iter->mtrr_state->fixed_ranges[iter->index];
+ return true;
+ }
+
+ if (iter->range) {
+ iter->mem_type = iter->range->base & 0xff;
+ return true;
+ }
+
+ return false;
+}
+
+static void mtrr_lookup_next(struct mtrr_iter *iter)
+{
+ if (iter->fixed)
+ mtrr_lookup_fixed_next(iter);
+ else
+ mtrr_lookup_var_next(iter);
+}
+
+#define mtrr_for_each_mem_type(_iter_, _mtrr_, _gpa_start_, _gpa_end_) \
+ for (mtrr_lookup_init(_iter_, _mtrr_, _gpa_start_, _gpa_end_); \
+ mtrr_lookup_okay(_iter_); mtrr_lookup_next(_iter_))
+
u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
--
2.1.0
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