[Qemu-devel] [PATCH v2 17/20] cpu: TLB_FLAGS_MASK bit to force memory slow path

[<tony.nguyen@bt.com>]

The fast path is taken when TLB_FLAGS_MASK is all zero.

TLB_FORCE_SLOW is simply a TLB_FLAGS_MASK bit to force the slow path,
there are no other side effects.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
---
 include/exec/cpu-all.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 536ea58..e496f99 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -331,12 +331,18 @@ CPUArchState *cpu_copy(CPUArchState *env);
 #define TLB_MMIO            (1 << (TARGET_PAGE_BITS - 3))
 /* Set if TLB entry must have MMU lookup repeated for every access */
 #define TLB_RECHECK         (1 << (TARGET_PAGE_BITS - 4))
+/* Set if TLB entry must take the slow path.  */
+#define TLB_FORCE_SLOW      (1 << (TARGET_PAGE_BITS - 5))

 /* Use this mask to check interception with an alignment mask
  * in a TCG backend.
  */
-#define TLB_FLAGS_MASK  (TLB_INVALID_MASK | TLB_NOTDIRTY | TLB_MMIO \
-                         | TLB_RECHECK)
+#define TLB_FLAGS_MASK \
+    (TLB_INVALID_MASK  \
+     | TLB_NOTDIRTY    \
+     | TLB_MMIO        \
+     | TLB_RECHECK     \
+     | TLB_FORCE_SLOW)

 /**
  * tlb_hit_page: return true if page aligned @addr is a hit against the
--
1.8.3.1