[PATCH v3 5/5] i386/cpu: Free env->xsave_buf in KVM and HVF destory_vcpu_thread routines

[Mark Kanda]

Create KVM and HVF specific destory_vcpu_thread() routines to free
env->xsave_buf.

vCPU hotunplug related leak reported by Valgrind:

==132362== 4,096 bytes in 1 blocks are definitely lost in loss record 8,440 of 
8,549
==132362==    at 0x4C3B15F: memalign (vg_replace_malloc.c:1265)
==132362==    by 0x4C3B288: posix_memalign (vg_replace_malloc.c:1429)
==132362==    by 0xB41195: qemu_try_memalign (memalign.c:53)
==132362==    by 0xB41204: qemu_memalign (memalign.c:73)
==132362==    by 0x7131CB: kvm_init_xsave (kvm.c:1601)
==132362==    by 0x7148ED: kvm_arch_init_vcpu (kvm.c:2031)
==132362==    by 0x91D224: kvm_init_vcpu (kvm-all.c:516)
==132362==    by 0x9242C9: kvm_vcpu_thread_fn (kvm-accel-ops.c:40)
==132362==    by 0xB2EB26: qemu_thread_start (qemu-thread-posix.c:556)
==132362==    by 0x7EB2159: start_thread (in /usr/lib64/libpthread-2.28.so)
==132362==    by 0x9D45DD2: clone (in /usr/lib64/libc-2.28.so)

Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
---
 accel/hvf/hvf-accel-ops.c | 11 ++++++++++-
 accel/kvm/kvm-accel-ops.c | 11 ++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
index b23a67881c..bc53890352 100644
--- a/accel/hvf/hvf-accel-ops.c
+++ b/accel/hvf/hvf-accel-ops.c
@@ -462,12 +462,21 @@ static void hvf_start_vcpu_thread(CPUState *cpu)
                        cpu, QEMU_THREAD_JOINABLE);
 }
 
+static void hvf_destroy_vcpu_thread(CPUState *cpu)
+{
+    X86CPU *x86_cpu = X86_CPU(cpu);
+    CPUX86State *env = &x86_cpu->env;
+
+    g_free(env->xsave_buf);
+    generic_destroy_vcpu_thread(cpu);
+}
+
 static void hvf_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
 
     ops->create_vcpu_thread = hvf_start_vcpu_thread;
-    ops->destroy_vcpu_thread = generic_destroy_vcpu_thread;
+    ops->destroy_vcpu_thread = hvf_destroy_vcpu_thread;
     ops->kick_vcpu_thread = hvf_kick_vcpu_thread;
 
     ops->synchronize_post_reset = hvf_cpu_synchronize_post_reset;
diff --git a/accel/kvm/kvm-accel-ops.c b/accel/kvm/kvm-accel-ops.c
index 5a7a9ae79c..0345a30139 100644
--- a/accel/kvm/kvm-accel-ops.c
+++ b/accel/kvm/kvm-accel-ops.c
@@ -74,6 +74,15 @@ static void kvm_start_vcpu_thread(CPUState *cpu)
                        cpu, QEMU_THREAD_JOINABLE);
 }
 
+static void kvm_destroy_vcpu_thread(CPUState *cpu)
+{
+    X86CPU *x86_cpu = X86_CPU(cpu);
+    CPUX86State *env = &x86_cpu->env;
+
+    g_free(env->xsave_buf);
+    generic_destroy_vcpu_thread(cpu);
+}
+
 static bool kvm_vcpu_thread_is_idle(CPUState *cpu)
 {
     return !kvm_halt_in_kernel();
@@ -89,7 +98,7 @@ static void kvm_accel_ops_class_init(ObjectClass *oc, void 
*data)
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
 
     ops->create_vcpu_thread = kvm_start_vcpu_thread;
-    ops->destroy_vcpu_thread = generic_destroy_vcpu_thread;
+    ops->destroy_vcpu_thread = kvm_destroy_vcpu_thread;
     ops->cpu_thread_is_idle = kvm_vcpu_thread_is_idle;
     ops->cpus_are_resettable = kvm_cpus_are_resettable;
     ops->synchronize_post_reset = kvm_cpu_synchronize_post_reset;
-- 
2.27.0