Add a new feature to get the unused page information from guest,
the unused page information is saved in the {pfn|length} arrays.
Please note that 'unused page' means page is not inuse sometime after
host set the value of request ID and before it receive response with
the same ID.
Signed-off-by: Liang Li <liang.z...@intel.com>
---
balloon.c | 47 +++++++++++-
hw/virtio/virtio-balloon.c | 149 ++++++++++++++++++++++++++++++++++++-
include/hw/virtio/virtio-balloon.h | 18 ++++-
include/sysemu/balloon.h | 18 ++++-
4 files changed, 227 insertions(+), 5 deletions(-)
diff --git a/balloon.c b/balloon.c
index f2ef50c..8efabe1 100644
--- a/balloon.c
+++ b/balloon.c
@@ -36,6 +36,8 @@
static QEMUBalloonEvent *balloon_event_fn;
static QEMUBalloonStatus *balloon_stat_fn;
+static QEMUBalloonGetUnusedPage *balloon_get_unused_page_fn;
+static QEMUBalloonUnusedPageReady *balloon_unused_page_ready_fn;
static void *balloon_opaque;
static bool balloon_inhibited;
@@ -65,9 +67,13 @@ static bool have_balloon(Error **errp)
}
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
- QEMUBalloonStatus *stat_func, void *opaque)
+ QEMUBalloonStatus *stat_func,
+ QEMUBalloonGetUnusedPage *get_unused_page_func,
+ QEMUBalloonUnusedPageReady
*unused_page_ready_func,
+ void *opaque)
{
- if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
+ if (balloon_event_fn || balloon_stat_fn || balloon_get_unused_page_fn
+ || balloon_unused_page_ready_fn || balloon_opaque) {
/* We're already registered one balloon handler. How many can
* a guest really have?
*/
@@ -75,6 +81,8 @@ int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
}
balloon_event_fn = event_func;
balloon_stat_fn = stat_func;
+ balloon_get_unused_page_fn = get_unused_page_func;
+ balloon_unused_page_ready_fn = unused_page_ready_func;
balloon_opaque = opaque;
return 0;
}
@@ -86,6 +94,8 @@ void qemu_remove_balloon_handler(void *opaque)
}
balloon_event_fn = NULL;
balloon_stat_fn = NULL;
+ balloon_get_unused_page_fn = NULL;
+ balloon_unused_page_ready_fn = NULL;
balloon_opaque = NULL;
}
@@ -116,3 +126,36 @@ void qmp_balloon(int64_t target, Error **errp)
trace_balloon_event(balloon_opaque, target);
balloon_event_fn(balloon_opaque, target);
}
+
+bool balloon_unused_pages_support(void)
+{
+ return balloon_get_unused_page_fn ? true : false;
+}
+
+BalloonReqStatus balloon_get_unused_pages(unsigned long *bitmap,
+ unsigned long len,
+ unsigned long req_id)
+{
+ if (!balloon_get_unused_page_fn) {
+ return REQ_UNSUPPORT;
+ }
+
+ if (!bitmap) {
+ return REQ_INVALID_PARAM;
+ }
+
+ return balloon_get_unused_page_fn(balloon_opaque, bitmap, len, req_id);
+}
+
+BalloonReqStatus balloon_unused_page_ready(unsigned long *req_id)
+{
+ if (!balloon_unused_page_ready_fn) {
+ return REQ_UNSUPPORT;
+ }
+
+ if (!req_id) {
+ return REQ_INVALID_PARAM;
+ }
+
+ return balloon_unused_page_ready_fn(balloon_opaque, req_id);
+}
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 4ab65ba..71c7e49 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -143,6 +143,13 @@ static bool balloon_page_ranges_supported(const
VirtIOBalloon *s)
return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_RANGE);
}
+static bool balloon_host_request_vq_supported(const VirtIOBalloon *s)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+
+ return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_HOST_REQ_VQ);
+}
+
static bool balloon_stats_enabled(const VirtIOBalloon *s)
{
return s->stats_poll_interval > 0;
@@ -394,6 +401,72 @@ out:
}
}
+static void virtio_balloon_handle_resp(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
+ VirtQueueElement *elem;
+ size_t offset = 0;
+ struct virtio_balloon_resp_hdr hdr;
+ uint64_t range;
+
+ elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+ if (!elem) {
+ s->req_status = REQ_ERROR;
+ return;
+ }
+
+ s->host_req_vq_elem = elem;
+ if (!elem->out_num) {
+ return;
+ }
+
+ iov_to_buf(elem->out_sg, elem->out_num, offset,
+ &hdr, sizeof(hdr));
+ offset += sizeof(hdr);
+
+ switch (hdr.cmd) {
+ case BALLOON_GET_UNUSED_PAGES:
+ if (hdr.id == s->host_req.param) {
+ if (s->bmap_len < hdr.data_len) {
+ hdr.data_len = s->bmap_len;
+ }
+
+ while (offset < hdr.data_len + sizeof(hdr)) {
+ unsigned long pfn, nr_page;
+
+ iov_to_buf(elem->out_sg, elem->out_num, offset, &range,
+ sizeof(range));
+
+ offset += sizeof(range);
+ pfn = range >> VIRTIO_BALLOON_NR_PFN_BITS;
+ nr_page = range & BALLOON_NR_PFN_MASK;
+ if (nr_page == 0) {
+ if (iov_to_buf(elem->out_sg, elem->out_num, offset, &range,
+ sizeof(range)) == sizeof(range)) {
+ nr_page = range;
+ offset += sizeof(range);
+ }
+ }
+ bitmap_set(s->unused_page_bmap, pfn, nr_page);
+ }
+
+ if (hdr.flag == BALLOON_FLAG_DONE) {
+ s->req_id = hdr.id;
+ s->req_status = REQ_DONE;
+ } else {
+ s->req_status = REQ_ON_GOING;
+ }
+ virtqueue_push(vq, elem, 0);
+ virtio_notify(vdev, vq);
+ g_free(elem);
+ }
+ break;
+ default:
+ break;
+ }
+
+}
+
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
@@ -473,6 +546,61 @@ static void virtio_balloon_stat(void *opaque, BalloonInfo
*info)
VIRTIO_BALLOON_PFN_SHIFT);
}
+static BalloonReqStatus virtio_balloon_free_pages(void *opaque,
+ unsigned long *bitmap,
+ unsigned long bmap_len,
+ unsigned long req_id)
+{
+ VirtIOBalloon *s = opaque;
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+ VirtQueueElement *elem = s->host_req_vq_elem;
+ int len;
+
+ if (!balloon_host_request_vq_supported(s)) {
+ return REQ_UNSUPPORT;
+ }
+
+ if (s->req_status == REQ_INIT || s->req_status == REQ_DONE) {
+ s->unused_page_bmap = bitmap;
+ if (elem == NULL || !elem->in_num) {
+ elem = virtqueue_pop(s->hvq, sizeof(VirtQueueElement));
+ if (!elem) {
+ return REQ_ERROR;
+ }
+ s->host_req_vq_elem = elem;
+ }
+ s->host_req.cmd = BALLOON_GET_UNUSED_PAGES;
+ s->host_req.param = req_id;
+ s->bmap_len = bmap_len;
+ len = iov_from_buf(elem->in_sg, elem->in_num, 0, &s->host_req,
+ sizeof(s->host_req));
+ virtqueue_push(s->hvq, elem, len);
+ virtio_notify(vdev, s->hvq);
+ g_free(s->host_req_vq_elem);
+ s->host_req_vq_elem = NULL;
+ s->req_status = REQ_ON_GOING;
+ return REQ_START;
+ }
+
+ return REQ_ON_GOING;
+}
+
+static BalloonReqStatus virtio_balloon_free_page_ready(void *opaque,
+ unsigned long *req_id)
+{
+ VirtIOBalloon *s = opaque;
+
+ if (!balloon_host_request_vq_supported(s)) {
+ return REQ_UNSUPPORT;
+ }
+
+ if (s->req_status == REQ_DONE) {
+ *req_id = s->req_id;
+ }
+
+ return s->req_status;
+}
+
static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
@@ -521,7 +649,9 @@ 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,
+ virtio_balloon_free_page_ready, s);
if (ret < 0) {
error_setg(errp, "Only one balloon device is supported");
@@ -532,8 +662,10 @@ 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->hvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_resp);
reset_stats(s);
+ s->req_status = REQ_INIT;
}
static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
@@ -555,6 +687,12 @@ static void virtio_balloon_device_reset(VirtIODevice *vdev)
g_free(s->stats_vq_elem);
s->stats_vq_elem = NULL;
}
+
+ if (s->host_req_vq_elem != NULL) {
+ g_free(s->host_req_vq_elem);
+ s->host_req_vq_elem = NULL;
+ }
+ s->req_status = REQ_INIT;
}
static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
@@ -567,6 +705,13 @@ static void virtio_balloon_set_status(VirtIODevice *vdev,
uint8_t status)
* was stopped */
virtio_balloon_receive_stats(vdev, s->svq);
}
+
+ if (!s->host_req_vq_elem && vdev->vm_running &&
+ (status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->hvq, 1)) {
+ /* poll misc queue for the element we have discarded when the VM
+ * was stopped */
+ virtio_balloon_handle_resp(vdev, s->hvq);
+ }
}
static void virtio_balloon_instance_init(Object *obj)
@@ -597,6 +742,8 @@ static Property virtio_balloon_properties[] = {
VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
DEFINE_PROP_BIT("page-ranges", VirtIOBalloon, host_features,
VIRTIO_BALLOON_F_PAGE_RANGE, true),
+ DEFINE_PROP_BIT("host-request-vq", VirtIOBalloon, host_features,
+ VIRTIO_BALLOON_F_HOST_REQ_VQ, true),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/include/hw/virtio/virtio-balloon.h
b/include/hw/virtio/virtio-balloon.h
index 1ea13bd..0af59af 100644
--- a/include/hw/virtio/virtio-balloon.h
+++ b/include/hw/virtio/virtio-balloon.h
@@ -23,6 +23,16 @@
#define VIRTIO_BALLOON(obj) \
OBJECT_CHECK(VirtIOBalloon, (obj), TYPE_VIRTIO_BALLOON)
+typedef enum {
+ REQ_INIT,
+ REQ_START,
+ REQ_ON_GOING,
+ REQ_DONE,
+ REQ_ERROR,
+ REQ_INVALID_PARAM,
+ REQ_UNSUPPORT,
+} BalloonReqStatus;
+
typedef struct virtio_balloon_stat VirtIOBalloonStat;
typedef struct virtio_balloon_stat_modern {
@@ -33,16 +43,22 @@ typedef struct virtio_balloon_stat_modern {
typedef struct VirtIOBalloon {
VirtIODevice parent_obj;
- VirtQueue *ivq, *dvq, *svq;
+ VirtQueue *ivq, *dvq, *svq, *hvq;
uint32_t num_pages;
uint32_t actual;
uint64_t stats[VIRTIO_BALLOON_S_NR];
VirtQueueElement *stats_vq_elem;
+ VirtQueueElement *host_req_vq_elem;
size_t stats_vq_offset;
QEMUTimer *stats_timer;
int64_t stats_last_update;
int64_t stats_poll_interval;
uint32_t host_features;
+ struct virtio_balloon_req_hdr host_req;
+ BalloonReqStatus req_status;
+ uint64_t *unused_page_bmap;
+ uint64_t bmap_len;
+ uint64_t req_id;
} VirtIOBalloon;
#endif
diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h
index af49e19..a642c83 100644
--- a/include/sysemu/balloon.h
+++ b/include/sysemu/balloon.h
@@ -15,14 +15,30 @@
#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 BalloonReqStatus (QEMUBalloonGetUnusedPage)(void *opaque,
+ unsigned long *bitmap,
+ unsigned long len,
+ unsigned long req_id);
+
+typedef BalloonReqStatus (QEMUBalloonUnusedPageReady)(void *opaque,
+ unsigned long *req_id);
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
- QEMUBalloonStatus *stat_func, void *opaque);
+ QEMUBalloonStatus *stat_func,
+ QEMUBalloonGetUnusedPage *get_unused_page_func,
+ QEMUBalloonUnusedPageReady
*unused_page_ready_func,
+ void *opaque);
void qemu_remove_balloon_handler(void *opaque);
bool qemu_balloon_is_inhibited(void);
void qemu_balloon_inhibit(bool state);
+bool balloon_unused_pages_support(void);
+BalloonReqStatus balloon_get_unused_pages(unsigned long *bitmap,
+ unsigned long len,
+ unsigned long req_id);
+BalloonReqStatus balloon_unused_page_ready(unsigned long *req_id);
#endif
--
1.9.1
