[PATCH v2 1/1] hw/ppc: free env->tb_env in spapr_unrealize_vcpu()

[Daniel Henrique Barboza <danielhb413@gmail.com>]

The timebase is allocated during spapr_realize_vcpu() and it's not
freed. This results in memory leaks when doing vcpu unplugs:

==636935==
==636935== 144 (96 direct, 48 indirect) bytes in 1 blocks are definitely lost in loss record 6
,461 of 8,135
==636935==    at 0x4897468: calloc (vg_replace_malloc.c:760)
==636935==    by 0x5077213: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.6400.4)
==636935==    by 0x507757F: g_malloc0_n (in /usr/lib64/libglib-2.0.so.0.6400.4)
==636935==    by 0x93C3FB: cpu_ppc_tb_init (ppc.c:1066)
==636935==    by 0x97BC2B: spapr_realize_vcpu (spapr_cpu_core.c:268)
==636935==    by 0x97C01F: spapr_cpu_core_realize (spapr_cpu_core.c:337)
==636935==    by 0xD4626F: device_set_realized (qdev.c:531)
==636935==    by 0xD55273: property_set_bool (object.c:2273)
==636935==    by 0xD523DF: object_property_set (object.c:1408)
==636935==    by 0xD588B7: object_property_set_qobject (qom-qobject.c:28)
==636935==    by 0xD52897: object_property_set_bool (object.c:1477)
==636935==    by 0xD4579B: qdev_realize (qdev.c:333)
==636935==

This patch adds a cpu_ppc_tb_free() helper in hw/ppc/ppc.c to allow us
to free the timebase. This leak is then solved by calling
cpu_ppc_tb_free() in spapr_unrealize_vcpu().

Fixes: 6f4b5c3ec590 ("spapr: CPU hot unplug support")
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/ppc.c            | 7 +++++++
 hw/ppc/spapr_cpu_core.c | 3 +++
 include/hw/ppc/ppc.h    | 1 +
 3 files changed, 11 insertions(+)

diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index faa02d6710..fea70df45e 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -1083,6 +1083,13 @@ clk_setup_cb cpu_ppc_tb_init (CPUPPCState *env, uint32_t freq)
     return &cpu_ppc_set_tb_clk;
 }
 
+void cpu_ppc_tb_free(CPUPPCState *env)
+{
+    timer_free(env->tb_env->decr_timer);
+    timer_free(env->tb_env->hdecr_timer);
+    g_free(env->tb_env);
+}
+
 /* cpu_ppc_hdecr_init may be used if the timer is not used by HDEC emulation */
 void cpu_ppc_hdecr_init(CPUPPCState *env)
 {
diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index ed84713960..8a4861f45a 100644
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -189,10 +189,13 @@ static const VMStateDescription vmstate_spapr_cpu_state = {
 
 static void spapr_unrealize_vcpu(PowerPCCPU *cpu, SpaprCpuCore *sc)
 {
+    CPUPPCState *env = &cpu->env;
+
     if (!sc->pre_3_0_migration) {
         vmstate_unregister(NULL, &vmstate_spapr_cpu_state, cpu->machine_data);
     }
     spapr_irq_cpu_intc_destroy(SPAPR_MACHINE(qdev_get_machine()), cpu);
+    cpu_ppc_tb_free(env);
     qdev_unrealize(DEVICE(cpu));
 }
 
diff --git a/include/hw/ppc/ppc.h b/include/hw/ppc/ppc.h
index b0ba4bd6b9..364f165b4b 100644
--- a/include/hw/ppc/ppc.h
+++ b/include/hw/ppc/ppc.h
@@ -54,6 +54,7 @@ struct ppc_tb_t {
 
 uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk, int64_t tb_offset);
 clk_setup_cb cpu_ppc_tb_init (CPUPPCState *env, uint32_t freq);
+void cpu_ppc_tb_free(CPUPPCState *env);
 void cpu_ppc_hdecr_init(CPUPPCState *env);
 void cpu_ppc_hdecr_exit(CPUPPCState *env);
 
-- 
2.35.1