accel: Fix vCPU memory leaks

[PATCH v4 12/13] softmmu/cpus: Free cpu->thread in generic_destroy_vcpu_thread()

Posted by Philippe Mathieu-Daudé 3 years, 10 months ago

From: Mark Kanda <mark.kanda@oracle.com>

Free cpu->thread in a new AccelOpsClass::destroy_vcpu_thread() handler
generic_destroy_vcpu_thread().

vCPU hotunplug related leak reported by Valgrind:

  ==102631== 8 bytes in 1 blocks are definitely lost in loss record 1,037 of 8,555
  ==102631==    at 0x4C3ADBB: calloc (vg_replace_malloc.c:1117)
  ==102631==    by 0x69EE4CD: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.5600.4)
  ==102631==    by 0x92443A: kvm_start_vcpu_thread (kvm-accel-ops.c:68)
  ==102631==    by 0x4505C2: qemu_init_vcpu (cpus.c:643)
  ==102631==    by 0x76B4D1: x86_cpu_realizefn (cpu.c:6520)
  ==102631==    by 0x9344A7: device_set_realized (qdev.c:531)
  ==102631==    by 0x93E329: property_set_bool (object.c:2273)
  ==102631==    by 0x93C2F8: object_property_set (object.c:1408)
  ==102631==    by 0x940796: object_property_set_qobject (qom-qobject.c:28)
  ==102631==    by 0x93C663: object_property_set_bool (object.c:1477)
  ==102631==    by 0x933D3B: qdev_realize (qdev.c:333)
  ==102631==    by 0x455EC4: qdev_device_add_from_qdict (qdev-monitor.c:713)

Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
Message-Id: <20220321141409.3112932-3-mark.kanda@oracle.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 softmmu/cpus.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index 37325b3b8d..efa8397f04 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -619,6 +619,7 @@ static void common_vcpu_thread_create(CPUState *cpu)
 
 static void common_vcpu_thread_destroy(CPUState *cpu)
 {
+    g_free(cpu->thread);
 }
 
 void cpu_remove_sync(CPUState *cpu)
-- 
2.35.1

Re: [PATCH v4 12/13] softmmu/cpus: Free cpu->thread in generic_destroy_vcpu_thread()

Posted by Richard Henderson 3 years, 10 months ago

On 3/23/22 10:17, Philippe Mathieu-Daudé wrote:
>   static void common_vcpu_thread_destroy(CPUState *cpu)
>   {
> +    g_free(cpu->thread);
>   }

Missing free of halt_cond.


r~

Re: [PATCH v4 12/13] softmmu/cpus: Free cpu->thread in generic_destroy_vcpu_thread()

Posted by Mark Kanda 3 years, 10 months ago

Thanks Philippe,

In the patch subject, 'generic_destroy_vcpu_thread()' should be changed to 
'common_vcpu_thread_destroy()'.
Same goes for the next patch (Free cpu->halt_cond).

Thanks/regards,
-Mark

On 3/23/2022 12:17 PM, Philippe Mathieu-Daudé wrote:
> From: Mark Kanda <mark.kanda@oracle.com>
>
> Free cpu->thread in a new AccelOpsClass::destroy_vcpu_thread() handler
> generic_destroy_vcpu_thread().
>
> vCPU hotunplug related leak reported by Valgrind:
>
>    ==102631== 8 bytes in 1 blocks are definitely lost in loss record 1,037 of 8,555
>    ==102631==    at 0x4C3ADBB: calloc (vg_replace_malloc.c:1117)
>    ==102631==    by 0x69EE4CD: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.5600.4)
>    ==102631==    by 0x92443A: kvm_start_vcpu_thread (kvm-accel-ops.c:68)
>    ==102631==    by 0x4505C2: qemu_init_vcpu (cpus.c:643)
>    ==102631==    by 0x76B4D1: x86_cpu_realizefn (cpu.c:6520)
>    ==102631==    by 0x9344A7: device_set_realized (qdev.c:531)
>    ==102631==    by 0x93E329: property_set_bool (object.c:2273)
>    ==102631==    by 0x93C2F8: object_property_set (object.c:1408)
>    ==102631==    by 0x940796: object_property_set_qobject (qom-qobject.c:28)
>    ==102631==    by 0x93C663: object_property_set_bool (object.c:1477)
>    ==102631==    by 0x933D3B: qdev_realize (qdev.c:333)
>    ==102631==    by 0x455EC4: qdev_device_add_from_qdict (qdev-monitor.c:713)
>
> Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
> Message-Id: <20220321141409.3112932-3-mark.kanda@oracle.com>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   softmmu/cpus.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/softmmu/cpus.c b/softmmu/cpus.c
> index 37325b3b8d..efa8397f04 100644
> --- a/softmmu/cpus.c
> +++ b/softmmu/cpus.c
> @@ -619,6 +619,7 @@ static void common_vcpu_thread_create(CPUState *cpu)
>   
>   static void common_vcpu_thread_destroy(CPUState *cpu)
>   {
> +    g_free(cpu->thread);
>   }
>   
>   void cpu_remove_sync(CPUState *cpu)