[Qemu-devel] [PATCH 3/3] s390x/helper: Added format control bit to MMU translation

[Jens Freimann]

From: Thomas Huth <address@hidden>

With the EDAT-1 facility, the MMU translation can stop at the
segment table already, pointing to a 1 MB block.

Signed-off-by: Thomas Huth <address@hidden>
Signed-off-by: Jens Freimann <address@hidden>
Reviewed-by: David Hildenbrand <address@hidden>
---
 target-s390x/cpu.h    | 4 ++++
 target-s390x/helper.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index f332d41..686d458 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -267,6 +267,9 @@ typedef struct CPUS390XState {
 #define FLAG_MASK_64            (PSW_MASK_64     >> 32)
 #define FLAG_MASK_32            0x00001000
 
+/* Control register 0 bits */
+#define CR0_EDAT                0x0000000000800000ULL
+
 static inline int cpu_mmu_index (CPUS390XState *env)
 {
     if (env->psw.mask & PSW_MASK_PSTATE) {
@@ -924,6 +927,7 @@ struct sysib_322 {
 #define _REGION_ENTRY_LENGTH    0x03      /* region third length              
*/
 
 #define _SEGMENT_ENTRY_ORIGIN   ~0x7ffULL /* segment table origin             
*/
+#define _SEGMENT_ENTRY_FC       0x400     /* format control                   
*/
 #define _SEGMENT_ENTRY_RO       0x200     /* page protection bit              
*/
 #define _SEGMENT_ENTRY_INV      0x20      /* invalid segment table entry      
*/
 
diff --git a/target-s390x/helper.c b/target-s390x/helper.c
index aa628b8..89dc6e7 100644
--- a/target-s390x/helper.c
+++ b/target-s390x/helper.c
@@ -217,6 +217,10 @@ static int mmu_translate_asce(CPUS390XState *env, 
target_ulong vaddr,
         offs = (vaddr >> 17) & 0x3ff8;
         break;
     case _ASCE_TYPE_SEGMENT:
+        if (env && (env->cregs[0] & CR0_EDAT) && (asce & _SEGMENT_ENTRY_FC)) {
+            *raddr = (asce & 0xfffffffffff00000ULL) | (vaddr & 0xfffff);
+            return 0;
+        }
         offs = (vaddr >> 9) & 0x07f8;
         origin = asce & _SEGMENT_ENTRY_ORIGIN;
         break;
-- 
1.8.5.5