s390x/gdb: expose virtualization specific registers

Let's expose some virtual/fake registers as virtualization specific
registers.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Message-Id: <1443689387-34473-3-git-send-email-jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

configure

@@ -5457,7 +5457,7 @@ case "$target_name" in
     echo "TARGET_ABI32=y" >> $config_target_mak
   ;;
   s390x)
-    gdb_xml_files="s390x-core64.xml s390-acr.xml s390-fpr.xml s390-vx.xml s390-cr.xml"
+    gdb_xml_files="s390x-core64.xml s390-acr.xml s390-fpr.xml s390-vx.xml s390-cr.xml s390-virt.xml"
   ;;
   tilegx)
   ;;

gdb-xml/s390-virt.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<!-- Copyright 2015 IBM Corp.
+
+     This work is licensed under the terms of the GNU GPL, version 2 or
+     (at your option) any later version. See the COPYING file in the
+     top-level directory. -->
+
+<!DOCTYPE feature SYSTEM "gdb-target.dtd">
+<feature name="org.gnu.gdb.s390.virt">
+  <reg name="ckc" bitsize="64" type="uint64" group="system"/>
+  <reg name="cputm" bitsize="64" type="uint64" group="system"/>
+  <reg name="last_break" bitsize="64" type="code_ptr" group="system"/>
+  <reg name="prefix" bitsize="64" type="data_ptr" group="system"/>
+  <reg name="pp" bitsize="64" type="uint64" group="system"/>
+  <reg name="pfault_token" bitsize="64" type="uint64" group="system"/>
+  <reg name="pfault_select" bitsize="64" type="uint64" group="system"/>
+  <reg name="pfault_compare" bitsize="64" type="uint64" group="system"/>
+</feature>

target-s390x/gdbstub.c

@@ -205,6 +205,82 @@ static int cpu_write_c_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
         return 0;
     }
 }
+
+/* the values represent the positions in s390-virt.xml */
+#define S390_VIRT_CKC_REGNUM    0
+#define S390_VIRT_CPUTM_REGNUM  1
+#define S390_VIRT_BEA_REGNUM    2
+#define S390_VIRT_PREFIX_REGNUM 3
+#define S390_VIRT_PP_REGNUM     4
+#define S390_VIRT_PFT_REGNUM    5
+#define S390_VIRT_PFS_REGNUM    6
+#define S390_VIRT_PFC_REGNUM    7
+/* total number of registers in s390-virt.xml */
+#define S390_NUM_VIRT_REGS 8
+
+static int cpu_read_virt_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
+    case S390_VIRT_CKC_REGNUM:
+        return gdb_get_regl(mem_buf, env->ckc);
+    case S390_VIRT_CPUTM_REGNUM:
+        return gdb_get_regl(mem_buf, env->cputm);
+    case S390_VIRT_BEA_REGNUM:
+        return gdb_get_regl(mem_buf, env->gbea);
+    case S390_VIRT_PREFIX_REGNUM:
+        return gdb_get_regl(mem_buf, env->psa);
+    case S390_VIRT_PP_REGNUM:
+        return gdb_get_regl(mem_buf, env->pp);
+    case S390_VIRT_PFT_REGNUM:
+        return gdb_get_regl(mem_buf, env->pfault_token);
+    case S390_VIRT_PFS_REGNUM:
+        return gdb_get_regl(mem_buf, env->pfault_select);
+    case S390_VIRT_PFC_REGNUM:
+        return gdb_get_regl(mem_buf, env->pfault_compare);
+    default:
+        return 0;
+    }
+}
+
+static int cpu_write_virt_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
+    case S390_VIRT_CKC_REGNUM:
+        env->ckc = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_CPUTM_REGNUM:
+        env->cputm = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_BEA_REGNUM:
+        env->gbea = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_PREFIX_REGNUM:
+        env->psa = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_PP_REGNUM:
+        env->pp = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_PFT_REGNUM:
+        env->pfault_token = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_PFS_REGNUM:
+        env->pfault_select = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    case S390_VIRT_PFC_REGNUM:
+        env->pfault_compare = ldtul_p(mem_buf);
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    default:
+        return 0;
+    }
+}
 #endif
 
 void s390_cpu_gdb_init(CPUState *cs)
@@ -225,5 +301,11 @@ void s390_cpu_gdb_init(CPUState *cs)
     gdb_register_coprocessor(cs, cpu_read_c_reg,
                              cpu_write_c_reg,
                              S390_NUM_C_REGS, "s390-cr.xml", 0);
+
+    if (kvm_enabled()) {
+        gdb_register_coprocessor(cs, cpu_read_virt_reg,
+                                 cpu_write_virt_reg,
+                                 S390_NUM_VIRT_REGS, "s390-virt.xml", 0);
+    }
 #endif
 }