Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20170421' into staging

migration/next for 20170421

# gpg: Signature made Fri 21 Apr 2017 11:28:13 BST
# gpg:                using RSA key 0xF487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration/20170421: (65 commits)
  hmp: info migrate_parameters format tunes
  hmp: info migrate_capability format tunes
  migration: rename max_size to threshold_size
  migration: set current_active_state once
  virtio-rng: stop virtqueue while the CPU is stopped
  migration: don't close a file descriptor while it can be in use
  ram: Remove migration_bitmap_extend()
  migration: Disable hotplug/unplug during migration
  qdev: Move qdev_unplug() to qdev-monitor.c
  qdev: Export qdev_hot_removed
  qdev: qdev_hotplug is really a bool
  migration: Remove MigrationState parameter from migration_is_idle()
  ram: Use RAMBitmap type for coherence
  ram: rename last_ram_offset() last_ram_pages()
  ram: Use ramblock and page offset instead of absolute offset
  ram: Change offset field in PageSearchStatus to page
  ram: Remember last_page instead of last_offset
  ram: Use page number instead of an address for the bitmap operations
  ram: reorganize last_sent_block
  ram: ram_discard_range() don't use the mis parameter
  ...

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

2 files changed, 26 insertions, 6 deletions

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 6926eedd3f..1f7a7c1ae1 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -11,8 +11,11 @@ virtio_set_status(void *vdev, uint8_t val) "vdev %p val %u"
 
 # hw/virtio/virtio-rng.c
 virtio_rng_guest_not_ready(void *rng) "rng %p: guest not ready"
+virtio_rng_cpu_is_stopped(void *rng, int size) "rng %p: cpu is stopped, dropping %d bytes"
+virtio_rng_popped(void *rng) "rng %p: elem popped"
 virtio_rng_pushed(void *rng, size_t len) "rng %p: %zd bytes pushed"
 virtio_rng_request(void *rng, size_t size, unsigned quota) "rng %p: %zd bytes requested, %u bytes quota left"
+virtio_rng_vm_state_change(void *rng, int running, int state) "rng %p: state change to running %d state %d"
 
 # hw/virtio/virtio-balloon.c
 #
diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
index 9639f4e89b..a6ee501051 100644
--- a/hw/virtio/virtio-rng.c
+++ b/hw/virtio/virtio-rng.c
@@ -53,6 +53,15 @@ static void chr_read(void *opaque, const void *buf, size_t size)
         return;
     }
 
+    /* we can't modify the virtqueue until
+     * our state is fully synced
+     */
+
+    if (!runstate_check(RUN_STATE_RUNNING)) {
+        trace_virtio_rng_cpu_is_stopped(vrng, size);
+        return;
+    }
+
     vrng->quota_remaining -= size;
 
     offset = 0;
@@ -61,6 +70,7 @@ static void chr_read(void *opaque, const void *buf, size_t size)
         if (!elem) {
             break;
         }
+        trace_virtio_rng_popped(vrng);
         len = iov_from_buf(elem->in_sg, elem->in_num,
                            0, buf + offset, size - offset);
         offset += len;
@@ -120,17 +130,21 @@ static uint64_t get_features(VirtIODevice *vdev, uint64_t f, Error **errp)
     return f;
 }
 
-static int virtio_rng_post_load(void *opaque, int version_id)
+static void virtio_rng_vm_state_change(void *opaque, int running,
+                                       RunState state)
 {
     VirtIORNG *vrng = opaque;
 
+    trace_virtio_rng_vm_state_change(vrng, running, state);
+
     /* We may have an element ready but couldn't process it due to a quota
-     * limit.  Make sure to try again after live migration when the quota may
-     * have been reset.
+     * limit or because CPU was stopped.  Make sure to try again when the
+     * CPU restart.
      */
-    virtio_rng_process(vrng);
 
-    return 0;
+    if (running && is_guest_ready(vrng)) {
+        virtio_rng_process(vrng);
+    }
 }
 
 static void check_rate_limit(void *opaque)
@@ -198,6 +212,9 @@ static void virtio_rng_device_realize(DeviceState *dev, Error **errp)
     vrng->rate_limit_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
                                                check_rate_limit, vrng);
     vrng->activate_timer = true;
+
+    vrng->vmstate = qemu_add_vm_change_state_handler(virtio_rng_vm_state_change,
+                                                     vrng);
 }
 
 static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp)
@@ -205,6 +222,7 @@ static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp)
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIORNG *vrng = VIRTIO_RNG(dev);
 
+    qemu_del_vm_change_state_handler(vrng->vmstate);
     timer_del(vrng->rate_limit_timer);
     timer_free(vrng->rate_limit_timer);
     virtio_cleanup(vdev);
@@ -218,7 +236,6 @@ static const VMStateDescription vmstate_virtio_rng = {
         VMSTATE_VIRTIO_DEVICE,
         VMSTATE_END_OF_LIST()
     },
-    .post_load =  virtio_rng_post_load,
 };
 
 static Property virtio_rng_properties[] = {