target/arm: Replace TARGET_PAGE_ENTRY_EXTRA

TARGET_PAGE_ENTRY_EXTRA is a macro that allows guests to specify additional
fields for caching with the full TLB entry.  This macro is replaced with
a union in CPUTLBEntryFull, thus making CPUTLB target-agnostic at the
cost of slightly inflated CPUTLBEntryFull for non-arm guests.

Note, this is needed to ensure that fields in CPUTLB don't vary in
offset between various targets.

(arm is the only guest actually making use of this feature.)

Signed-off-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230912153428.17816-2-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/exec/cpu-defs.h

@@ -135,9 +135,21 @@ typedef struct CPUTLBEntryFull {
      * This may be used to cache items from the guest cpu
      * page tables for later use by the implementation.
      */
-#ifdef TARGET_PAGE_ENTRY_EXTRA
-    TARGET_PAGE_ENTRY_EXTRA
-#endif
+    union {
+        /*
+         * Cache the attrs and shareability fields from the page table entry.
+         *
+         * For ARMMMUIdx_Stage2*, pte_attrs is the S2 descriptor bits [5:2].
+         * Otherwise, pte_attrs is the same as the MAIR_EL1 8-bit format.
+         * For shareability and guarded, as in the SH and GP fields respectively
+         * of the VMSAv8-64 PTEs.
+         */
+        struct {
+            uint8_t pte_attrs;
+            uint8_t shareability;
+            bool guarded;
+        } arm;
+    } extra;
 } CPUTLBEntryFull;
 #endif /* CONFIG_SOFTMMU */
 

target/arm/cpu-param.h

@@ -31,18 +31,6 @@
 # define TARGET_PAGE_BITS_VARY
 # define TARGET_PAGE_BITS_MIN  10
 
-/*
- * Cache the attrs and shareability fields from the page table entry.
- *
- * For ARMMMUIdx_Stage2*, pte_attrs is the S2 descriptor bits [5:2].
- * Otherwise, pte_attrs is the same as the MAIR_EL1 8-bit format.
- * For shareability and guarded, as in the SH and GP fields respectively
- * of the VMSAv8-64 PTEs.
- */
-# define TARGET_PAGE_ENTRY_EXTRA  \
-    uint8_t pte_attrs;            \
-    uint8_t shareability;         \
-    bool guarded;
 #endif
 
 #endif

target/arm/ptw.c

@@ -579,7 +579,7 @@ static bool S1_ptw_translate(CPUARMState *env, S1Translate *ptw,
         }
         ptw->out_phys = full->phys_addr | (addr & ~TARGET_PAGE_MASK);
         ptw->out_rw = full->prot & PAGE_WRITE;
-        pte_attrs = full->pte_attrs;
+        pte_attrs = full->extra.arm.pte_attrs;
         ptw->out_space = full->attrs.space;
 #else
         g_assert_not_reached();
@@ -2036,7 +2036,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
 
         /* When in aarch64 mode, and BTI is enabled, remember GP in the TLB. */
         if (aarch64 && cpu_isar_feature(aa64_bti, cpu)) {
-            result->f.guarded = extract64(attrs, 50, 1); /* GP */
+            result->f.extra.arm.guarded = extract64(attrs, 50, 1); /* GP */
         }
     }
 

target/arm/tcg/mte_helper.c

@@ -137,7 +137,7 @@ static uint8_t *allocation_tag_mem_probe(CPUARMState *env, int ptr_mmu_idx,
     assert(!(flags & TLB_INVALID_MASK));
 
     /* If the virtual page MemAttr != Tagged, access unchecked. */
-    if (full->pte_attrs != 0xf0) {
+    if (full->extra.arm.pte_attrs != 0xf0) {
         return NULL;
     }
 

target/arm/tcg/sve_helper.c

@@ -5373,7 +5373,7 @@ bool sve_probe_page(SVEHostPage *info, bool nofault, CPUARMState *env,
     info->tagged = (flags & PAGE_ANON) && (flags & PAGE_MTE);
 #else
     info->attrs = full->attrs;
-    info->tagged = full->pte_attrs == 0xf0;
+    info->tagged = full->extra.arm.pte_attrs == 0xf0;
 #endif
 
     /* Ensure that info->host[] is relative to addr, not addr + mem_off. */

target/arm/tcg/tlb_helper.c

@@ -334,8 +334,8 @@ bool arm_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
             address &= TARGET_PAGE_MASK;
         }
 
-        res.f.pte_attrs = res.cacheattrs.attrs;
-        res.f.shareability = res.cacheattrs.shareability;
+        res.f.extra.arm.pte_attrs = res.cacheattrs.attrs;
+        res.f.extra.arm.shareability = res.cacheattrs.shareability;
 
         tlb_set_page_full(cs, mmu_idx, address, &res.f);
         return true;

target/arm/tcg/translate-a64.c

@@ -13904,7 +13904,7 @@ static bool is_guarded_page(CPUARMState *env, DisasContext *s)
                               false, &host, &full, 0);
     assert(!(flags & TLB_INVALID_MASK));
 
-    return full->guarded;
+    return full->extra.arm.guarded;
 #endif
 }