Re: [Qemu-devel] [PATCH 1/1] s390-cpu: qom interface for S390 cpu states array

[Paolo Bonzini]

Il 07/03/2014 17:29, Jason J. Herne ha scritto:
From: "Jason J. Herne" <jjhe...@us.ibm.com>
Rename the S390 ipi_states array to cpu_states to better reflect its contents.

Create machine/cpu[cpu_addr] links within the qom tree when creating a new cpu.

Encapsulate the qom tree linking process and the management of the cpu_states
array into helper functions.

Signed-off-by: Jason J. Herne <jjhe...@us.ibm.com>
---
 hw/s390x/s390-virtio.c | 30 ++++++++++++++++++++++++------
 target-s390x/cpu.h     |  1 +
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
index 9eeda97..82411e7 100644
--- a/hw/s390x/s390-virtio.c
+++ b/hw/s390x/s390-virtio.c
@@ -52,15 +52,33 @@
 #define ZIPL_FILENAME                   "s390-zipl.rom"

 static VirtIOS390Bus *s390_bus;
-static S390CPU **ipi_states;
+static S390CPU **cpu_states;

 S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
 {
+    gchar *name;
+    Object *cpu;
+
     if (cpu_addr >= smp_cpus) {
         return NULL;
     }

-    return ipi_states[cpu_addr];
+    name = g_strdup_printf("cpu[%i]", cpu_addr);
+    cpu = object_property_get_link(qdev_get_machine(), name, NULL);
+
+    g_free(name);
+    return S390_CPU(cpu);
+}

QOM is too slow to be used in the data path.

I don't think you want a malloc + a linear scan of an array in 
css_inject_io_interrupt, so you should keep using cpu_states here.

Paolo

+void s390_cpu_set_cpustate(uint16_t cpu_addr, S390CPU *state)
+{
+    gchar *name;
+
+    cpu_states[cpu_addr] = state;
+    name = g_strdup_printf("cpu[%i]", cpu_addr);
+    object_property_add_link(qdev_get_machine(), name, TYPE_S390_CPU,
+                            (Object **) &cpu_states[cpu_addr], NULL);
+    g_free(name);
 }

 static int s390_virtio_hcall_notify(const uint64_t *args)
@@ -184,16 +202,16 @@ void s390_init_cpus(const char *cpu_model, uint8_t 
*storage_keys)
         cpu_model = "host";
     }

-    ipi_states = g_malloc(sizeof(S390CPU *) * smp_cpus);
+    cpu_states = g_malloc(sizeof(S390CPU *) * smp_cpus);

     for (i = 0; i < smp_cpus; i++) {
-        S390CPU *cpu;
+        S390CPU* cpu;
         CPUState *cs;

         cpu = cpu_s390x_init(cpu_model);
-        cs = CPU(cpu);
+        s390_cpu_set_cpustate(i, cpu);

-        ipi_states[i] = cpu;
+        cs = CPU(cpu_states[i]);
         cs->halted = 1;
         cpu->env.exception_index = EXCP_HLT;
         cpu->env.storage_keys = storage_keys;
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 96c2b4a..6ce3b64 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -370,6 +370,7 @@ static inline void kvm_s390_interrupt_internal(S390CPU 
*cpu, int type,
 }
 #endif
 S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
+void s390_cpu_set_cpustate(uint16_t cpu_addr, S390CPU *state);
 void s390_add_running_cpu(S390CPU *cpu);
 unsigned s390_del_running_cpu(S390CPU *cpu);