s390x: machine reset function with new ipl cpu handling

Current implementation depends on the order of resets getting triggered.

If a cpu reset is triggered after the ipl device reset, the CPU is stopped and
the VM will not run. In fact, that hinders us from converting the ipl device
into a TYPE_DEVICE. Let's change that by manually configuring the ipl cpu
during a system reset, so we have full control and can demangle that code.

Also remove the superflous cpu parameter from s390_update_iplstate on the way.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

hw/s390x/ipl.c

@@ -223,7 +223,7 @@ static Property s390_ipl_properties[] = {
  * - -1 if no valid boot device was found
  * - ccw id of the boot device otherwise
  */
-static uint64_t s390_update_iplstate(CPUS390XState *env, S390IPLState *ipl)
+static uint64_t s390_update_iplstate(S390IPLState *ipl)
 {
     DeviceState *dev_st;
 
@@ -282,26 +282,27 @@ void s390_reipl_request(void)
     qemu_system_reset_request();
 }
 
+void s390_ipl_prepare_cpu(S390CPU *cpu)
+{
+    S390IPLState *ipl = get_ipl_device();
+
+    cpu->env.psw.addr = ipl->start_addr;
+    cpu->env.psw.mask = IPL_PSW_MASK;
+
+    if (!ipl->kernel || ipl->iplb_valid) {
+        cpu->env.psw.addr = ipl->bios_start_addr;
+        cpu->env.regs[7] = s390_update_iplstate(ipl);
+    }
+}
+
 static void s390_ipl_reset(DeviceState *dev)
 {
     S390IPLState *ipl = S390_IPL(dev);
-    S390CPU *cpu = S390_CPU(qemu_get_cpu(0));
-    CPUS390XState *env = &cpu->env;
-
-    env->psw.addr = ipl->start_addr;
-    env->psw.mask = IPL_PSW_MASK;
 
     if (!ipl->reipl_requested) {
         ipl->iplb_valid = false;
     }
     ipl->reipl_requested = false;
-
-    if (!ipl->kernel || ipl->iplb_valid) {
-        env->psw.addr = ipl->bios_start_addr;
-        env->regs[7] = s390_update_iplstate(env, ipl);
-    }
-
-    s390_cpu_set_state(CPU_STATE_OPERATING, cpu);
 }
 
 static void s390_ipl_class_init(ObjectClass *klass, void *data)

hw/s390x/ipl.h

@@ -12,6 +12,8 @@
 #ifndef HW_S390_IPL_H
 #define HW_S390_IPL_H
 
+#include "cpu.h"
+
 typedef struct IplParameterBlock {
       uint8_t  reserved1[110];
       uint16_t devno;
@@ -19,6 +21,7 @@ typedef struct IplParameterBlock {
 } IplParameterBlock;
 
 void s390_ipl_update_diag308(IplParameterBlock *iplb);
+void s390_ipl_prepare_cpu(S390CPU *cpu);
 IplParameterBlock *s390_ipl_get_iplb(void);
 void s390_reipl_request(void);
 

hw/s390x/s390-virtio-ccw.c

@@ -161,6 +161,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
     NMIClass *nc = NMI_CLASS(oc);
 
     mc->init = ccw_init;
+    mc->reset = s390_machine_reset;
     mc->block_default_type = IF_VIRTIO;
     mc->no_cdrom = 1;
     mc->no_floppy = 1;

hw/s390x/s390-virtio.c

@@ -40,6 +40,7 @@
 #include "hw/s390x/s390_flic.h"
 #include "hw/s390x/s390-virtio.h"
 #include "hw/s390x/storage-keys.h"
+#include "hw/s390x/ipl.h"
 #include "cpu.h"
 
 //#define DEBUG_S390
@@ -314,6 +315,17 @@ void s390_nmi(NMIState *n, int cpu_index, Error **errp)
     }
 }
 
+void s390_machine_reset(void)
+{
+    S390CPU *ipl_cpu = S390_CPU(qemu_get_cpu(0));
+
+    qemu_devices_reset();
+
+    /* all cpus are stopped - configure and start the ipl cpu only */
+    s390_ipl_prepare_cpu(ipl_cpu);
+    s390_cpu_set_state(CPU_STATE_OPERATING, ipl_cpu);
+}
+
 static void s390_machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -322,6 +334,7 @@ static void s390_machine_class_init(ObjectClass *oc, void *data)
     mc->alias = "s390";
     mc->desc = "VirtIO based S390 machine";
     mc->init = s390_init;
+    mc->reset = s390_machine_reset;
     mc->block_default_type = IF_VIRTIO;
     mc->max_cpus = 255;
     mc->no_serial = 1;

hw/s390x/s390-virtio.h

@@ -27,5 +27,6 @@ void s390_init_ipl_dev(const char *kernel_filename,
                        bool enforce_bios);
 void s390_create_virtio_net(BusState *bus, const char *name);
 void s390_nmi(NMIState *n, int cpu_index, Error **errp);
+void s390_machine_reset(void);
 void s390_memory_init(ram_addr_t mem_size);
 #endif