s390x/kvm: proper use of the cpu states OPERATING and STOPPED

This patch makes sure that halting a cpu and stopping a cpu are two different
things. Stopping a cpu will also set the cpu halted - this is needed for common
infrastructure to work (note that the stop and stopped flag cannot be used for
our purpose because they are already used by other mechanisms).

A cpu can be halted ("waiting") when it is operating. If interrupts are
disabled, this is called a "disabled wait", as it can't be woken up anymore. A
stopped cpu is treated like a "disabled wait" cpu, but in order to prepare for a
proper cpu state synchronization with the kvm part, we need to track the real
logical state of a cpu.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Andreas Faerber <afaerber@suse.de>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index f1a3ad2..7b9300e 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -407,8 +407,9 @@ static inline void kvm_s390_service_interrupt(uint32_t parm)
 }
 #endif
 S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
-void s390_add_running_cpu(S390CPU *cpu);
-unsigned s390_del_running_cpu(S390CPU *cpu);
+unsigned int s390_cpu_halt(S390CPU *cpu);
+void s390_cpu_unhalt(S390CPU *cpu);
+unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu);
 
 /* service interrupts are floating therefore we must not pass an cpustate */
 void s390_sclp_extint(uint32_t parm);
@@ -417,11 +418,16 @@ void s390_sclp_extint(uint32_t parm);
 extern const hwaddr virtio_size;
 
 #else
-static inline void s390_add_running_cpu(S390CPU *cpu)
+static inline unsigned int s390_cpu_halt(S390CPU *cpu)
+{
+    return 0;
+}
+
+static inline void s390_cpu_unhalt(S390CPU *cpu)
 {
 }
 
-static inline unsigned s390_del_running_cpu(S390CPU *cpu)
+static inline unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
 {
     return 0;
 }