[Qemu-devel] [PATCH 09/23] s390x/gdb: support reading/writing of control registers

[Cornelia Huck <cornelia.huck@de.ibm.com>]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

Let's support reading and writing of control registers for kvm and tcg.

We have to take care of flushing the tlb (tcg) and pushing the changed
registers into kvm.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 configure              |  2 +-
 gdb-xml/s390-cr.xml    | 26 ++++++++++++++++++++++++++
 target-s390x/gdbstub.c | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 gdb-xml/s390-cr.xml

diff --git a/configure b/configure
index 9d24d59..8279aec 100755
--- a/configure
+++ b/configure
@@ -5384,7 +5384,7 @@ 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"
+    gdb_xml_files="s390x-core64.xml s390-acr.xml s390-fpr.xml s390-vx.xml s390-cr.xml"
   ;;
   tricore)
   ;;
diff --git a/gdb-xml/s390-cr.xml b/gdb-xml/s390-cr.xml
new file mode 100644
index 0000000..5246bea
--- /dev/null
+++ b/gdb-xml/s390-cr.xml
@@ -0,0 +1,26 @@
+<?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.cr">
+  <reg name="cr0" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr1" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr2" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr3" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr4" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr5" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr6" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr7" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr8" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr9" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr10" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr11" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr12" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr13" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr14" bitsize="64" type="uint64" group="control"/>
+  <reg name="cr15" bitsize="64" type="uint64" group="control"/>
+</feature>
diff --git a/target-s390x/gdbstub.c b/target-s390x/gdbstub.c
index 31f2049..0c39a3c 100644
--- a/target-s390x/gdbstub.c
+++ b/target-s390x/gdbstub.c
@@ -174,6 +174,39 @@ static int cpu_write_vreg(CPUS390XState *env, uint8_t *mem_buf, int n)
     }
 }
 
+/* the values represent the positions in s390-cr.xml */
+#define S390_C0_REGNUM 0
+#define S390_C15_REGNUM 15
+/* total number of registers in s390-cr.xml */
+#define S390_NUM_C_REGS 16
+
+#ifndef CONFIG_USER_ONLY
+static int cpu_read_c_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
+    case S390_C0_REGNUM ... S390_C15_REGNUM:
+        return gdb_get_regl(mem_buf, env->cregs[n]);
+    default:
+        return 0;
+    }
+}
+
+static int cpu_write_c_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
+    case S390_C0_REGNUM ... S390_C15_REGNUM:
+        env->cregs[n] = ldtul_p(mem_buf);
+        if (tcg_enabled()) {
+            tlb_flush(ENV_GET_CPU(env), 1);
+        }
+        cpu_synchronize_post_init(ENV_GET_CPU(env));
+        return 8;
+    default:
+        return 0;
+    }
+}
+#endif
+
 void s390_cpu_gdb_init(CPUState *cs)
 {
     gdb_register_coprocessor(cs, cpu_read_ac_reg,
@@ -187,4 +220,10 @@ void s390_cpu_gdb_init(CPUState *cs)
     gdb_register_coprocessor(cs, cpu_read_vreg,
                              cpu_write_vreg,
                              S390_NUM_VREGS, "s390-vx.xml", 0);
+
+#ifndef CONFIG_USER_ONLY
+    gdb_register_coprocessor(cs, cpu_read_c_reg,
+                             cpu_write_c_reg,
+                             S390_NUM_C_REGS, "s390-cr.xml", 0);
+#endif
 }
-- 
2.5.1