On Tue, Feb 06, 2018 at 07:08:19PM +0800, Wei Wang wrote:
> This patch adds a timer to limit the time that host waits for the free
> page hints reported by the guest. Users can specify the time in ms via
> "free-page-wait-time" command line option. If a user doesn't specify a
> time, host waits till the guest finishes reporting all the free page
> hints. The policy (wait for all the free page hints to be reported or
> use a time limit) is determined by the orchestration layer.
>
> Signed-off-by: Wei Wang <wei.w.w...@intel.com>
> CC: Michael S. Tsirkin <m...@redhat.com>
Looks like an option the migration command should get,
as opposed to a device feature.
> ---
> hw/virtio/virtio-balloon.c | 84
> +++++++++++++++++++++++++++++++++++++-
> hw/virtio/virtio-pci.c | 3 ++
> include/hw/virtio/virtio-balloon.h | 4 ++
> 3 files changed, 90 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
> index b424d4e..9ee0de4 100644
> --- a/hw/virtio/virtio-balloon.c
> +++ b/hw/virtio/virtio-balloon.c
> @@ -207,6 +207,65 @@ static void balloon_stats_set_poll_interval(Object *obj,
> Visitor *v,
> balloon_stats_change_timer(s, 0);
> }
>
> +static void balloon_free_page_change_timer(VirtIOBalloon *s, int64_t ms)
> +{
> + timer_mod(s->free_page_timer,
> + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + ms);
> +}
> +
> +static void balloon_stop_free_page_report(void *opaque)
> +{
> + VirtIOBalloon *dev = opaque;
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +
> + timer_del(dev->free_page_timer);
> + timer_free(dev->free_page_timer);
> + dev->free_page_timer = NULL;
> +
> + if (dev->free_page_report_status == FREE_PAGE_REPORT_S_START) {
> + dev->host_stop_free_page = true;
> + virtio_notify_config(vdev);
> + }
> +}
> +
> +static void balloon_free_page_get_wait_time(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOBalloon *s = opaque;
> +
> + visit_type_int(v, name, &s->free_page_wait_time, errp);
> +}
> +
> +static void balloon_free_page_set_wait_time(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOBalloon *s = opaque;
> + Error *local_err = NULL;
> + int64_t value;
> +
> + visit_type_int(v, name, &value, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + return;
> + }
> + if (value < 0) {
> + error_setg(errp, "free page wait time must be greater than zero");
> + return;
> + }
> +
> + if (value > UINT32_MAX) {
> + error_setg(errp, "free page wait time value is too big");
> + return;
> + }
> +
> + s->free_page_wait_time = value;
> + g_assert(s->free_page_timer == NULL);
> + s->free_page_timer = timer_new_ms(QEMU_CLOCK_REALTIME,
> + balloon_stop_free_page_report, s);
> +}
> +
> static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> {
> VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
> @@ -330,6 +389,7 @@ static void
> virtio_balloon_poll_free_page_hints(VirtIOBalloon *dev)
> if (id == dev->free_page_report_cmd_id) {
> dev->free_page_report_status = FREE_PAGE_REPORT_S_START;
> } else {
> + dev->host_stop_free_page = false;
> dev->free_page_report_status = FREE_PAGE_REPORT_S_STOP;
> break;
> }
> @@ -385,6 +445,10 @@ static void virtio_balloon_free_page_poll(void *opaque)
> virtio_notify_config(vdev);
> s->free_page_report_status = FREE_PAGE_REPORT_S_REQUESTED;
>
> + if (s->free_page_wait_time) {
> + balloon_free_page_change_timer(s, s->free_page_wait_time);
> + }
> +
> virtio_balloon_poll_free_page_hints(s);
> }
>
> @@ -395,7 +459,19 @@ static void virtio_balloon_get_config(VirtIODevice
> *vdev, uint8_t *config_data)
>
> config.num_pages = cpu_to_le32(dev->num_pages);
> config.actual = cpu_to_le32(dev->actual);
> - config.free_page_report_cmd_id =
> cpu_to_le32(dev->free_page_report_cmd_id);
> + if (dev->host_stop_free_page) {
> + /*
> + * Host is actively requesting to stop the free page reporting, send
> + * the stop sign to the guest. This happens when the migration thread
> + * has reached the phase to send pages to the destination while the
> + * guest hasn't done the reporting.
> + */
> + config.free_page_report_cmd_id =
> + VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID;
> + } else {
> + config.free_page_report_cmd_id =
> +
> cpu_to_le32(dev->free_page_report_cmd_id);
> + }
>
> trace_virtio_balloon_get_config(config.num_pages, config.actual);
> memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
> @@ -539,6 +615,7 @@ static void virtio_balloon_device_realize(DeviceState
> *dev, Error **errp)
> s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE, NULL);
> s->free_page_report_status = FREE_PAGE_REPORT_S_STOP;
> s->free_page_report_cmd_id = VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID;
> + s->host_stop_free_page = false;
> }
> reset_stats(s);
> }
> @@ -602,6 +679,11 @@ static void virtio_balloon_instance_init(Object *obj)
> balloon_stats_get_poll_interval,
> balloon_stats_set_poll_interval,
> NULL, s, NULL);
> +
> + object_property_add(obj, "free-page-wait-time", "int",
> + balloon_free_page_get_wait_time,
> + balloon_free_page_set_wait_time,
> + NULL, s, NULL);
> }
>
> static const VMStateDescription vmstate_virtio_balloon = {
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 6c75cca..3345104 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -2250,6 +2250,9 @@ static void virtio_balloon_pci_instance_init(Object
> *obj)
> object_property_add_alias(obj, "guest-stats-polling-interval",
> OBJECT(&dev->vdev),
> "guest-stats-polling-interval", &error_abort);
> + object_property_add_alias(obj, "free-page-wait-time",
> + OBJECT(&dev->vdev),
> + "free-page-wait-time", &error_abort);
> }
>
> static const TypeInfo virtio_balloon_pci_info = {
> diff --git a/include/hw/virtio/virtio-balloon.h
> b/include/hw/virtio/virtio-balloon.h
> index 11b4e01..c16855b 100644
> --- a/include/hw/virtio/virtio-balloon.h
> +++ b/include/hw/virtio/virtio-balloon.h
> @@ -40,6 +40,8 @@ enum virtio_balloon_free_page_report_status {
> typedef struct VirtIOBalloon {
> VirtIODevice parent_obj;
> VirtQueue *ivq, *dvq, *svq, *free_page_vq;
> + /* Host is requesting the guest to stop free page reporting */
> + bool host_stop_free_page;
> uint32_t free_page_report_status;
> uint32_t num_pages;
> uint32_t actual;
> @@ -49,8 +51,10 @@ typedef struct VirtIOBalloon {
> VirtQueueElement *stats_vq_elem;
> size_t stats_vq_offset;
> QEMUTimer *stats_timer;
> + QEMUTimer *free_page_timer;
> int64_t stats_last_update;
> int64_t stats_poll_interval;
> + int64_t free_page_wait_time;
> uint32_t host_features;
> } VirtIOBalloon;
>
> --
> 1.8.3.1
