Extend the virtio balloon device to support a new feature, this
new feature can help to get guest's free pages information, which
can be used for live migration optimzation.
Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx>
---
balloon.c | 29 +++++++-
hw/virtio/virtio-balloon.c | 92 ++++++++++++++++++++++++-
include/hw/virtio/virtio-balloon.h | 30 +++++++-
include/standard-headers/linux/virtio_balloon.h | 1 +
include/sysemu/balloon.h | 12 +++-
5 files changed, 159 insertions(+), 5 deletions(-)
diff --git a/balloon.c b/balloon.c
index f2ef50c..346e215 100644
--- a/balloon.c
+++ b/balloon.c
@@ -36,6 +36,7 @@
static QEMUBalloonEvent *balloon_event_fn;
static QEMUBalloonStatus *balloon_stat_fn;
+static QEMUBalloonGetFreePage *balloon_get_free_page_fn;
static void *balloon_opaque;
static bool balloon_inhibited;
@@ -65,9 +66,12 @@ static bool have_balloon(Error **errp)
}
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
- QEMUBalloonStatus *stat_func, void *opaque)
+ QEMUBalloonStatus *stat_func,
+ QEMUBalloonGetFreePage *get_free_page_func,
+ void *opaque)
{
- if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
+ if (balloon_event_fn || balloon_stat_fn || balloon_get_free_page_fn
+ || balloon_opaque) {
/* We're already registered one balloon handler. How many can
* a guest really have?
*/
@@ -75,6 +79,7 @@ int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
}
balloon_event_fn = event_func;
balloon_stat_fn = stat_func;
+ balloon_get_free_page_fn = get_free_page_func;
balloon_opaque = opaque;
return 0;
}
@@ -86,6 +91,7 @@ void qemu_remove_balloon_handler(void *opaque)
}
balloon_event_fn = NULL;
balloon_stat_fn = NULL;
+ balloon_get_free_page_fn = NULL;
balloon_opaque = NULL;
}
@@ -116,3 +122,22 @@ void qmp_balloon(int64_t target, Error **errp)
trace_balloon_event(balloon_opaque, target);
balloon_event_fn(balloon_opaque, target);
}
+
+bool balloon_free_pages_support(void)
+{
+ return balloon_get_free_page_fn ? true : false;
+}
+
+FreePageStatus balloon_get_free_pages(unsigned long *bitmap,
+ unsigned long len, int drop_cache)
+{
+ if (!balloon_get_free_page_fn) {
+ return FREE_PAGE_UNSUPPORT;
+ }
+
+ if (!bitmap) {
+ return FREE_PAGE_INVALID_PARAM;
+ }
+
+ return balloon_get_free_page_fn(balloon_opaque, bitmap, len, drop_cache);
+}
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 9dbe681..0abf375 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -78,6 +78,12 @@ static bool balloon_stats_supported(const VirtIOBalloon *s)
return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ);
}
+static bool balloon_free_pages_supported(const VirtIOBalloon *s)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+ return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_GET_FREE_PAGE);
+}
+
static bool balloon_stats_enabled(const VirtIOBalloon *s)
{
return s->stats_poll_interval > 0;
@@ -304,6 +310,38 @@ out:
}
}
+static void virtio_balloon_get_free_pages(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
+ VirtQueueElement *elem;
+ size_t offset = 0;
+ uint64_t bitmap_bytes = 0;
+
+ elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+ if (!elem) {
+ s->req_status = REQ_ERROR;
+ return;
+ }
+
+ s->free_page_vq_elem = elem;
+
+ if (!elem->out_num) {
+ return;
+ }
+
+ iov_to_buf(elem->out_sg, elem->out_num, offset,
+ &bitmap_bytes, sizeof(uint64_t));
+
+ if (s->bmap_len < bitmap_bytes) {
+ s->req_status = REQ_INVALID_PARAM;
+ return;
+ }
+ offset += sizeof(uint64_t);
+ iov_to_buf(elem->out_sg, elem->out_num, offset,
+ s->free_page_bmap, bitmap_bytes);
+ s->req_status = REQ_DONE;
+}
+
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
@@ -373,6 +411,7 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
f |= dev->host_features;
virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
+ virtio_add_feature(&f, VIRTIO_BALLOON_F_GET_FREE_PAGE);
return f;
}
@@ -383,6 +422,48 @@ static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
VIRTIO_BALLOON_PFN_SHIFT);
}
+static FreePageStatus virtio_balloon_free_pages(void *opaque,
+ unsigned long *bitmap,
+ unsigned long bmap_len,
+ int drop_cache_ctl)
+{
+ VirtIOBalloon *s = opaque;
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+ VirtQueueElement *elem = s->free_page_vq_elem;
+ int len;
+
+ if (!balloon_free_pages_supported(s)) {
+ return FREE_PAGE_UNSUPPORT;
+ }
+
+ if (s->req_status == REQ_INIT) {
+ s->free_page_bmap = bitmap;
+ if (elem == NULL || !elem->in_num) {
+ elem = virtqueue_pop(s->fvq, sizeof(VirtQueueElement));
+ if (!elem) {
+ return FREE_PAGE_ERROR;
+ }
+ s->free_page_vq_elem = elem;
+ }
+ s->free_page_req.param = drop_cache_ctl;
+ s->bmap_len = bmap_len;
+ len = iov_from_buf(elem->in_sg, elem->in_num, 0, &s->free_page_req,
+ sizeof(s->free_page_req));
+ virtqueue_push(s->fvq, elem, len);
+ virtio_notify(vdev, s->fvq);
+ g_free(s->free_page_vq_elem);
+ s->free_page_vq_elem = NULL;
+ s->req_status = REQ_ON_GOING;
+ return FREE_PAGE_REQ;
+ } else if (s->req_status == REQ_ON_GOING) {
+ return FREE_PAGE_WAITING_FOR_RSP;
+ } else if (s->req_status == REQ_DONE) {
+ s->req_status = REQ_INIT;
+ }
+
+ return FREE_PAGE_READY;
+}
+
static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
@@ -444,7 +525,8 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
sizeof(struct virtio_balloon_config));
ret = qemu_add_balloon_handler(virtio_balloon_to_target,
- virtio_balloon_stat, s);
+ virtio_balloon_stat,
+ virtio_balloon_free_pages, s);
if (ret < 0) {
error_setg(errp, "Only one balloon device is supported");
@@ -455,8 +537,10 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
+ s->fvq = virtio_add_queue(vdev, 128, virtio_balloon_get_free_pages);
reset_stats(s);
+ s->req_status = REQ_INIT;
register_savevm(dev, "virtio-balloon", -1, 1,
virtio_balloon_save, virtio_balloon_load, s);
@@ -481,6 +565,12 @@ static void virtio_balloon_device_reset(VirtIODevice *vdev)
g_free(s->stats_vq_elem);
s->stats_vq_elem = NULL;
}
+
+ if (s->free_page_vq_elem != NULL) {
+ g_free(s->free_page_vq_elem);
+ s->free_page_vq_elem = NULL;
+ }
+ s->req_status = REQ_INIT;
}
static void virtio_balloon_instance_init(Object *obj)
diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h
index 35f62ac..fbed81c 100644
--- a/include/hw/virtio/virtio-balloon.h
+++ b/include/hw/virtio/virtio-balloon.h
@@ -23,6 +23,27 @@
#define VIRTIO_BALLOON(obj) \
OBJECT_CHECK(VirtIOBalloon, (obj), TYPE_VIRTIO_BALLOON)
+typedef enum {
+ REQ_INIT,
+ REQ_ON_GOING,
+ REQ_DONE,
+ REQ_ERROR,
+ REQ_INVALID_PARAM,
+} VirtIoReqStatus;
+
+typedef enum {
+ FREE_PAGE_REQ,
+ FREE_PAGE_WAITING_FOR_RSP,
+ FREE_PAGE_READY,
+ FREE_PAGE_INVALID_PARAM,
+ FREE_PAGE_UNSUPPORT,
+ FREE_PAGE_ERROR,
+} FreePageStatus;
+
+typedef struct GetFreePageReq {
+ uint64_t param;
+} GetFreePageReq;
+
typedef struct virtio_balloon_stat VirtIOBalloonStat;
typedef struct virtio_balloon_stat_modern {
@@ -33,16 +54,23 @@ typedef struct virtio_balloon_stat_modern {
typedef struct VirtIOBalloon {
VirtIODevice parent_obj;
- VirtQueue *ivq, *dvq, *svq;
+ VirtQueue *ivq, *dvq, *svq, *fvq;
uint32_t num_pages;
uint32_t actual;
uint64_t stats[VIRTIO_BALLOON_S_NR];
VirtQueueElement *stats_vq_elem;
+ VirtQueueElement *free_page_vq_elem;
size_t stats_vq_offset;
QEMUTimer *stats_timer;
int64_t stats_last_update;
int64_t stats_poll_interval;
uint32_t host_features;
+ uint64_t *free_page_bmap;
+ uint64_t bmap_len;
+ uint64_t free_pages;
+ uint64_t cache_pages;
+ GetFreePageReq free_page_req;
+ VirtIoReqStatus req_status;
} VirtIOBalloon;
#endif
diff --git a/include/standard-headers/linux/virtio_balloon.h b/include/standard-headers/linux/virtio_balloon.h
index 9d06ccd..09211b0 100644
--- a/include/standard-headers/linux/virtio_balloon.h
+++ b/include/standard-headers/linux/virtio_balloon.h
@@ -34,6 +34,7 @@
#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
+#define VIRTIO_BALLOON_F_GET_FREE_PAGE 3 /* Get the free page bitmap */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h
index 3f976b4..81a1b9f 100644
--- a/include/sysemu/balloon.h
+++ b/include/sysemu/balloon.h
@@ -15,14 +15,24 @@
#define _QEMU_BALLOON_H
#include "qapi-types.h"
+#include "hw/virtio/virtio-balloon.h"
typedef void (QEMUBalloonEvent)(void *opaque, ram_addr_t target);
typedef void (QEMUBalloonStatus)(void *opaque, BalloonInfo *info);
+typedef FreePageStatus (QEMUBalloonGetFreePage)(void *opaque,
+ unsigned long *bitmap,
+ unsigned long len,
+ int drop_cache_ctl);
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
- QEMUBalloonStatus *stat_func, void *opaque);
+ QEMUBalloonStatus *stat_func,
+ QEMUBalloonGetFreePage *get_free_page_func,
+ void *opaque);
void qemu_remove_balloon_handler(void *opaque);
bool qemu_balloon_is_inhibited(void);
void qemu_balloon_inhibit(bool state);
+bool balloon_free_pages_support(void);
+FreePageStatus balloon_get_free_pages(unsigned long *bitmap,
+ unsigned long len, int drop_cache_ctl);
#endif
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
