s390/kvm: do not reset riccb on initial cpu reset

The riccb is kept unchanged during initial cpu reset. Move the data
structure to the other registers that are unchanged.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

target/s390x/cpu.c

@@ -92,9 +92,10 @@ static void s390_cpu_initial_reset(CPUState *s)
     int i;
 
     s390_cpu_reset(s);
-    /* initial reset does not touch regs,fregs and aregs */
-    memset(&env->fpc, 0, offsetof(CPUS390XState, end_reset_fields) -
-                         offsetof(CPUS390XState, fpc));
+    /* initial reset does not clear everything! */
+    memset(&env->start_initial_reset_fields, 0,
+        offsetof(CPUS390XState, end_reset_fields) -
+        offsetof(CPUS390XState, start_initial_reset_fields));
 
     /* architectured initial values for CR 0 and 14 */
     env->cregs[0] = CR0_RESET;

target/s390x/cpu.h

@@ -88,6 +88,10 @@ typedef struct CPUS390XState {
      */
     CPU_DoubleU vregs[32][2];  /* vector registers */
     uint32_t aregs[16];    /* access registers */
+    uint8_t riccb[64];     /* runtime instrumentation control */
+
+    /* Fields up to this point are not cleared by initial CPU reset */
+    struct {} start_initial_reset_fields;
 
     uint32_t fpc;          /* floating-point control register */
     uint32_t cc_op;
@@ -137,8 +141,6 @@ typedef struct CPUS390XState {
     uint64_t gbea;
     uint64_t pp;
 
-    uint8_t riccb[64];
-
     /* Fields up to this point are cleared by a CPU reset */
     struct {} end_reset_fields;