target/arm: Adjust the order of Phys and Stage2 ARMMMUIdx

It will be helpful to have ARMMMUIdx_Phys_* to be in the same
relative order as ARMSecuritySpace enumerators. This requires
the adjustment to the nstable check. While there, check for being
in secure state rather than rely on clearing the low bit making
no change to non-secure state.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230620124418.805717-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/cpu.h

@@ -2860,18 +2860,18 @@ typedef enum ARMMMUIdx {
     ARMMMUIdx_E2        = 6 | ARM_MMU_IDX_A,
     ARMMMUIdx_E3        = 7 | ARM_MMU_IDX_A,
 
-    /* TLBs with 1-1 mapping to the physical address spaces. */
-    ARMMMUIdx_Phys_NS   = 8 | ARM_MMU_IDX_A,
-    ARMMMUIdx_Phys_S    = 9 | ARM_MMU_IDX_A,
-
     /*
      * Used for second stage of an S12 page table walk, or for descriptor
      * loads during first stage of an S1 page table walk.  Note that both
      * are in use simultaneously for SecureEL2: the security state for
      * the S2 ptw is selected by the NS bit from the S1 ptw.
      */
-    ARMMMUIdx_Stage2    = 10 | ARM_MMU_IDX_A,
-    ARMMMUIdx_Stage2_S  = 11 | ARM_MMU_IDX_A,
+    ARMMMUIdx_Stage2_S  = 8 | ARM_MMU_IDX_A,
+    ARMMMUIdx_Stage2    = 9 | ARM_MMU_IDX_A,
+
+    /* TLBs with 1-1 mapping to the physical address spaces. */
+    ARMMMUIdx_Phys_S    = 10 | ARM_MMU_IDX_A,
+    ARMMMUIdx_Phys_NS   = 11 | ARM_MMU_IDX_A,
 
     /*
      * These are not allocated TLBs and are used only for AT system

target/arm/ptw.c

@@ -1449,16 +1449,14 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
     descaddr |= (address >> (stride * (4 - level))) & indexmask;
     descaddr &= ~7ULL;
     nstable = !regime_is_stage2(mmu_idx) && extract32(tableattrs, 4, 1);
-    if (nstable) {
+    if (nstable && ptw->in_secure) {
         /*
          * Stage2_S -> Stage2 or Phys_S -> Phys_NS
-         * Assert that the non-secure idx are even, and relative order.
+         * Assert the relative order of the secure/non-secure indexes.
          */
-        QEMU_BUILD_BUG_ON((ARMMMUIdx_Phys_NS & 1) != 0);
-        QEMU_BUILD_BUG_ON((ARMMMUIdx_Stage2 & 1) != 0);
-        QEMU_BUILD_BUG_ON(ARMMMUIdx_Phys_NS + 1 != ARMMMUIdx_Phys_S);
-        QEMU_BUILD_BUG_ON(ARMMMUIdx_Stage2 + 1 != ARMMMUIdx_Stage2_S);
-        ptw->in_ptw_idx &= ~1;
+        QEMU_BUILD_BUG_ON(ARMMMUIdx_Phys_S + 1 != ARMMMUIdx_Phys_NS);
+        QEMU_BUILD_BUG_ON(ARMMMUIdx_Stage2_S + 1 != ARMMMUIdx_Stage2);
+        ptw->in_ptw_idx += 1;
         ptw->in_secure = false;
     }
     if (!S1_ptw_translate(env, ptw, descaddr, fi)) {