diff mbox

[01/10] cpus: protect work list with work_mutex

Message ID 1439397664-70734-2-git-send-email-pbonzini@redhat.com
State New
Headers show

Commit Message

Paolo Bonzini Aug. 12, 2015, 4:40 p.m. UTC 
From: KONRAD Frederic <fred.konrad@greensocs.com>

Protect the list of queued work items with something other than
the BQL, as a preparation for running the work items outside it.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 cpus.c            | 22 ++++++++++++++++++----
 include/qom/cpu.h |  6 +++++-
 qom/cpu.c         |  1 +
 3 files changed, 24 insertions(+), 5 deletions(-)

Comments

Peter Maydell Aug. 28, 2015, 2:33 p.m. UTC | #1 
On 12 August 2015 at 17:40, Paolo Bonzini <pbonzini@redhat.com> wrote:
> From: KONRAD Frederic <fred.konrad@greensocs.com>
>
> Protect the list of queued work items with something other than
> the BQL, as a preparation for running the work items outside it.
>
> Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox

Patch

diff --git a/cpus.c b/cpus.c
index c1e74d9..9224488 100644
--- a/cpus.c
+++ b/cpus.c
@@ -845,6 +845,8 @@  void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data)
     wi.func = func;
     wi.data = data;
     wi.free = false;
+
+    qemu_mutex_lock(&cpu->work_mutex);
     if (cpu->queued_work_first == NULL) {
         cpu->queued_work_first = &wi;
     } else {
@@ -853,9 +855,10 @@  void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data)
     cpu->queued_work_last = &wi;
     wi.next = NULL;
     wi.done = false;
+    qemu_mutex_unlock(&cpu->work_mutex);
 
     qemu_cpu_kick(cpu);
-    while (!wi.done) {
+    while (!atomic_mb_read(&wi.done)) {
         CPUState *self_cpu = current_cpu;
 
         qemu_cond_wait(&qemu_work_cond, &qemu_global_mutex);
@@ -876,6 +879,8 @@  void async_run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data)
     wi->func = func;
     wi->data = data;
     wi->free = true;
+
+    qemu_mutex_lock(&cpu->work_mutex);
     if (cpu->queued_work_first == NULL) {
         cpu->queued_work_first = wi;
     } else {
@@ -884,6 +889,7 @@  void async_run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data)
     cpu->queued_work_last = wi;
     wi->next = NULL;
     wi->done = false;
+    qemu_mutex_unlock(&cpu->work_mutex);
 
     qemu_cpu_kick(cpu);
 }
@@ -896,15 +902,23 @@  static void flush_queued_work(CPUState *cpu)
         return;
     }
 
-    while ((wi = cpu->queued_work_first)) {
+    qemu_mutex_lock(&cpu->work_mutex);
+    while (cpu->queued_work_first != NULL) {
+        wi = cpu->queued_work_first;
         cpu->queued_work_first = wi->next;
+        if (!cpu->queued_work_first) {
+            cpu->queued_work_last = NULL;
+        }
+        qemu_mutex_unlock(&cpu->work_mutex);
         wi->func(wi->data);
-        wi->done = true;
+        qemu_mutex_lock(&cpu->work_mutex);
         if (wi->free) {
             g_free(wi);
+        } else {
+            atomic_mb_set(&wi->done, true);
         }
     }
-    cpu->queued_work_last = NULL;
+    qemu_mutex_unlock(&cpu->work_mutex);
     qemu_cond_broadcast(&qemu_work_cond);
 }
 
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 39712ab..77bbff2 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -244,6 +244,8 @@  struct kvm_run;
  * @mem_io_pc: Host Program Counter at which the memory was accessed.
  * @mem_io_vaddr: Target virtual address at which the memory was accessed.
  * @kvm_fd: vCPU file descriptor for KVM.
+ * @work_mutex: Lock to prevent multiple access to queued_work_*.
+ * @queued_work_first: First asynchronous work pending.
  *
  * State of one CPU core or thread.
  */
@@ -264,7 +266,6 @@  struct CPUState {
     uint32_t host_tid;
     bool running;
     struct QemuCond *halt_cond;
-    struct qemu_work_item *queued_work_first, *queued_work_last;
     bool thread_kicked;
     bool created;
     bool stop;
@@ -275,6 +276,9 @@  struct CPUState {
     int64_t icount_extra;
     sigjmp_buf jmp_env;
 
+    QemuMutex work_mutex;
+    struct qemu_work_item *queued_work_first, *queued_work_last;
+
     AddressSpace *as;
     struct AddressSpaceDispatch *memory_dispatch;
     MemoryListener *tcg_as_listener;
diff --git a/qom/cpu.c b/qom/cpu.c
index 62f4b5d..3e93223 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -314,6 +314,7 @@  static void cpu_common_initfn(Object *obj)
 
     cpu->cpu_index = -1;
     cpu->gdb_num_regs = cpu->gdb_num_g_regs = cc->gdb_num_core_regs;
+    qemu_mutex_init(&cpu->work_mutex);
     QTAILQ_INIT(&cpu->breakpoints);
     QTAILQ_INIT(&cpu->watchpoints);
 }