[Qemu-devel] [PATCH 7/7] SPARC64: implement addtional MMU faults related to nonfaulting load

[Tsuneo Saito <tsnsaito@gmail.com>]

This patch implements MMU faults caused by TTE.NFO and TTE.E:
- access other than nonfaulting load to a page marked NFO should
  raise data_access_exception
- nonfaulting load to a page marked with E bit should raise
  data_access_exception

To distinguish nonfaulting loads, this patch extends (abuses?) the rw
argument of get_physical_address_data().  rw is set to 4 on nonfaulting
loads.

Signed-off-by: Tsuneo Saito <tsnsaito@gmail.com>
---
 target-sparc/cpu.h    |    4 ++++
 target-sparc/helper.c |   29 ++++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/target-sparc/cpu.h b/target-sparc/cpu.h
index f4eeff5..a51863c 100644
--- a/target-sparc/cpu.h
+++ b/target-sparc/cpu.h
@@ -290,15 +290,19 @@ enum {
 #endif
 
 #define TTE_VALID_BIT       (1ULL << 63)
+#define TTE_NFO_BIT         (1ULL << 60)
 #define TTE_USED_BIT        (1ULL << 41)
 #define TTE_LOCKED_BIT      (1ULL <<  6)
+#define TTE_SIDEEFFECT_BIT  (1ULL <<  3)
 #define TTE_PRIV_BIT        (1ULL <<  2)
 #define TTE_W_OK_BIT        (1ULL <<  1)
 #define TTE_GLOBAL_BIT      (1ULL <<  0)
 
 #define TTE_IS_VALID(tte)   ((tte) & TTE_VALID_BIT)
+#define TTE_IS_NFO(tte)     ((tte) & TTE_NFO_BIT)
 #define TTE_IS_USED(tte)    ((tte) & TTE_USED_BIT)
 #define TTE_IS_LOCKED(tte)  ((tte) & TTE_LOCKED_BIT)
+#define TTE_IS_SIDEEFFECT(tte) ((tte) & TTE_SIDEEFFECT_BIT)
 #define TTE_IS_PRIV(tte)    ((tte) & TTE_PRIV_BIT)
 #define TTE_IS_W_OK(tte)    ((tte) & TTE_W_OK_BIT)
 #define TTE_IS_GLOBAL(tte)  ((tte) & TTE_GLOBAL_BIT)
diff --git a/target-sparc/helper.c b/target-sparc/helper.c
index b6e62a7..acc07f5 100644
--- a/target-sparc/helper.c
+++ b/target-sparc/helper.c
@@ -445,27 +445,50 @@ static int get_physical_address_data(CPUState *env,
 
     if (rw == 1) {
         sfsr |= SFSR_WRITE_BIT;
+    } else if (rw == 4) {
+        sfsr |= SFSR_NF_BIT;
     }
 
     for (i = 0; i < 64; i++) {
         // ctx match, vaddr match, valid?
         if (ultrasparc_tag_match(&env->dtlb[i], address, context, physical)) {
+            int do_fault = 0;
 
             // access ok?
+            /* multiple bits in SFSR.FT may be set on TT_DFAULT */
             if (TTE_IS_PRIV(env->dtlb[i].tte) && is_user) {
+                do_fault = 1;
                 sfsr |= SFSR_FT_PRIV_BIT; /* privilege violation */
-                env->exception_index = TT_DFAULT;
 
                 DPRINTF_MMU("DFAULT at %" PRIx64 " context %" PRIx64
                             " mmu_idx=%d tl=%d\n",
                             address, context, mmu_idx, env->tl);
+            }
+            if (rw == 4) {
+                if (TTE_IS_SIDEEFFECT(env->dtlb[i].tte)) {
+                    do_fault = 1;
+                    sfsr |= SFSR_FT_NF_E_BIT;
+                }
+            } else {
+                if (TTE_IS_NFO(env->dtlb[i].tte)) {
+                    do_fault = 1;
+                    sfsr |= SFSR_FT_NFO_BIT;
+                }
+            }
+
+            if (do_fault) {
+                /* faults above are reported with TT_DFAULT. */
+                env->exception_index = TT_DFAULT;
             } else if (!TTE_IS_W_OK(env->dtlb[i].tte) && (rw == 1)) {
+                do_fault = 1;
                 env->exception_index = TT_DPROT;
 
                 DPRINTF_MMU("DPROT at %" PRIx64 " context %" PRIx64
                             " mmu_idx=%d tl=%d\n",
                             address, context, mmu_idx, env->tl);
-            } else {
+            }
+
+            if (!do_fault) {
                 *prot = PAGE_READ;
                 if (TTE_IS_W_OK(env->dtlb[i].tte)) {
                     *prot |= PAGE_WRITE;
@@ -752,7 +775,7 @@ target_phys_addr_t cpu_get_phys_page_nofault(CPUState *env, target_ulong addr,
 {
     target_phys_addr_t phys_addr;
 
-    if (cpu_sparc_get_phys_page(env, &phys_addr, addr, 0, mmu_idx) != 0) {
+    if (cpu_sparc_get_phys_page(env, &phys_addr, addr, 4, mmu_idx) != 0) {
         return -1;
     }
     return phys_addr;
-- 
1.7.5.4