This patch has been discussed (and ACKed) in the past, but has not yet been committed due to the congestion surrounding the 0.12 release and other conflicting changes. I would like to rekindle the discussion so that I can make the necessary changes to get this merged.
This patch is ported to 0.12.1 and has one issue that I am aware of: It still calls monitor_suspend() and monitor_resume() which I understand is no longer allowed. Does anyone have any ideas on how to enable async monitor commands? diff --git a/balloon.h b/balloon.h index 60b4a5d..dc851d3 100644 --- a/balloon.h +++ b/balloon.h @@ -16,12 +16,12 @@ #include "cpu-defs.h" -typedef ram_addr_t (QEMUBalloonEvent)(void *opaque, ram_addr_t target); +typedef QObject *(QEMUBalloonEvent)(void *opaque, ram_addr_t target); void qemu_add_balloon_handler(QEMUBalloonEvent *func, void *opaque); -void qemu_balloon(ram_addr_t target); +int qemu_balloon(ram_addr_t target); -ram_addr_t qemu_balloon_status(void); +QObject *qemu_balloon_status(void); #endif diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c index cfd3b41..03b9e2e 100644 --- a/hw/virtio-balloon.c +++ b/hw/virtio-balloon.c @@ -19,6 +19,10 @@ #include "balloon.h" #include "virtio-balloon.h" #include "kvm.h" +#include "monitor.h" +#include "qlist.h" +#include "qint.h" +#include "qstring.h" #if defined(__linux__) #include <sys/mman.h> @@ -27,9 +31,13 @@ typedef struct VirtIOBalloon { VirtIODevice vdev; - VirtQueue *ivq, *dvq; + VirtQueue *ivq, *dvq, *svq; uint32_t num_pages; uint32_t actual; + uint64_t stats[VIRTIO_BALLOON_S_NR]; + VirtQueueElement stats_vq_elem; + size_t stats_vq_offset; + uint8_t stats_requested; } VirtIOBalloon; static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev) @@ -46,6 +54,33 @@ static void balloon_page(void *addr, int deflate) #endif } +static inline void reset_stats(VirtIOBalloon *dev) +{ + int i; + for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); +} + +static void stat_put(QDict *dict, const char *label, uint64_t val) +{ + if (val != -1) + qdict_put(dict, label, qint_from_int(val)); +} + +static QObject *get_stats_qobject(VirtIOBalloon *dev) +{ + QDict *dict = qdict_new(); + uint32_t actual = ram_size - (dev->actual << VIRTIO_BALLOON_PFN_SHIFT); + + stat_put(dict, "actual", actual); + stat_put(dict, "mem_swapped_in", dev->stats[VIRTIO_BALLOON_S_SWAP_IN]); + stat_put(dict, "mem_swapped_out", dev->stats[VIRTIO_BALLOON_S_SWAP_OUT]); + stat_put(dict, "major_page_faults", dev->stats[VIRTIO_BALLOON_S_MAJFLT]); + stat_put(dict, "minor_page_faults", dev->stats[VIRTIO_BALLOON_S_MINFLT]); + stat_put(dict, "free_mem", dev->stats[VIRTIO_BALLOON_S_MEMFREE]); + stat_put(dict, "total_mem", dev->stats[VIRTIO_BALLOON_S_MEMTOT]); + return QOBJECT(dict); +} + /* FIXME: once we do a virtio refactoring, this will get subsumed into common * code */ static size_t memcpy_from_iovector(void *data, size_t offset, size_t size, @@ -104,6 +139,36 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) } } +static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) +{ + VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); + VirtQueueElement *elem = &s->stats_vq_elem; + VirtIOBalloonStat stat; + size_t offset = 0; + + if (!virtqueue_pop(vq, elem)) + return; + + while (memcpy_from_iovector(&stat, offset, sizeof(stat), elem->out_sg, + elem->out_num) == sizeof(stat)) { + uint16_t tag = tswap16(stat.tag); + uint64_t val = tswap64(stat.val); + + offset += sizeof(stat); + if (tag < VIRTIO_BALLOON_S_NR) + s->stats[tag] = val; + } + s->stats_vq_offset = offset; + + if (s->stats_requested) { + QObject *stats = get_stats_qobject(s); + monitor_print_balloon(cur_mon, stats); + qobject_decref(stats); + monitor_resume(cur_mon); + s->stats_requested = 0; + } +} + static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) { VirtIOBalloon *dev = to_virtio_balloon(vdev); @@ -126,12 +191,22 @@ static void virtio_balloon_set_config(VirtIODevice *vdev, static uint32_t virtio_balloon_get_features(VirtIODevice *vdev) { - return 0; + return 1 << VIRTIO_BALLOON_F_STATS_VQ; +} + +static void request_stats(VirtIOBalloon *vb) +{ + vb->stats_requested = 1; + reset_stats(vb); + monitor_suspend(cur_mon); + virtqueue_push(vb->svq, &vb->stats_vq_elem, vb->stats_vq_offset); + virtio_notify(&vb->vdev, vb->svq); } -static ram_addr_t virtio_balloon_to_target(void *opaque, ram_addr_t target) +static QObject *virtio_balloon_to_target(void *opaque, ram_addr_t target) { VirtIOBalloon *dev = opaque; + QObject *ret = NULL; if (target > ram_size) target = ram_size; @@ -139,9 +214,15 @@ static ram_addr_t virtio_balloon_to_target(void *opaque, ram_addr_t target) if (target) { dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; virtio_notify_config(&dev->vdev); + } else if (dev->vdev.features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) { + request_stats(dev); + ret = QOBJECT(qdict_new()); + } else { + reset_stats(dev); + ret = get_stats_qobject(dev); } - return ram_size - (dev->actual << VIRTIO_BALLOON_PFN_SHIFT); + return ret; } static void virtio_balloon_save(QEMUFile *f, void *opaque) @@ -152,6 +233,9 @@ static void virtio_balloon_save(QEMUFile *f, void *opaque) qemu_put_be32(f, s->num_pages); qemu_put_be32(f, s->actual); + qemu_put_buffer(f, (uint8_t *)&s->stats_vq_elem, sizeof(VirtQueueElement)); + qemu_put_buffer(f, (uint8_t *)&s->stats_vq_offset, sizeof(size_t)); + qemu_put_byte(f, s->stats_requested); } static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) @@ -165,6 +249,9 @@ static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) s->num_pages = qemu_get_be32(f); s->actual = qemu_get_be32(f); + qemu_get_buffer(f, (uint8_t *)&s->stats_vq_elem, sizeof(VirtQueueElement)); + qemu_get_buffer(f, (uint8_t *)&s->stats_vq_offset, sizeof(size_t)); + s->stats_requested = qemu_get_byte(f); return 0; } @@ -183,6 +270,7 @@ VirtIODevice *virtio_balloon_init(DeviceState *dev) s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output); s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output); + s->svq = virtio_add_queue(&s->vdev, 128, virtio_balloon_receive_stats); qemu_add_balloon_handler(virtio_balloon_to_target, s); diff --git a/hw/virtio-balloon.h b/hw/virtio-balloon.h index 9a0d119..e20cf6b 100644 --- a/hw/virtio-balloon.h +++ b/hw/virtio-balloon.h @@ -25,6 +25,7 @@ /* The feature bitmap for virtio balloon */ #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ +#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory stats virtqueue */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 @@ -37,4 +38,18 @@ struct virtio_balloon_config uint32_t actual; }; +/* Memory Statistics */ +#define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ +#define VIRTIO_BALLOON_S_SWAP_OUT 1 /* Amount of memory swapped out */ +#define VIRTIO_BALLOON_S_MAJFLT 2 /* Number of major faults */ +#define VIRTIO_BALLOON_S_MINFLT 3 /* Number of minor faults */ +#define VIRTIO_BALLOON_S_MEMFREE 4 /* Total amount of free memory */ +#define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of memory */ +#define VIRTIO_BALLOON_S_NR 6 + +typedef struct VirtIOBalloonStat { + uint16_t tag; + uint64_t val; +} __attribute__((packed)) VirtIOBalloonStat; + #endif diff --git a/monitor.c b/monitor.c index c0dc48e..c4a669a 100644 --- a/monitor.c +++ b/monitor.c @@ -2058,43 +2058,27 @@ static void do_info_status(Monitor *mon, QObject **ret_data) vm_running, singlestep); } -static ram_addr_t balloon_get_value(void) +static void print_balloon_stat(const char *key, QObject *obj, void *opaque) { - ram_addr_t actual; - - if (kvm_enabled() && !kvm_has_sync_mmu()) { - qemu_error_new(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon"); - return 0; - } - - actual = qemu_balloon_status(); - if (actual == 0) { - qemu_error_new(QERR_DEVICE_NOT_ACTIVE, "balloon"); - return 0; - } - - return actual; -} + Monitor *mon = opaque; -/** - * do_balloon(): Request VM to change its memory allocation - */ -static void do_balloon(Monitor *mon, const QDict *qdict, QObject **ret_data) -{ - if (balloon_get_value()) { - /* ballooning is active */ - qemu_balloon(qdict_get_int(qdict, "value")); - } + if (strcmp(key, "actual")) + monitor_printf(mon, ",%s=%" PRId64, key, + qint_get_int(qobject_to_qint(obj))); } -static void monitor_print_balloon(Monitor *mon, const QObject *data) +void monitor_print_balloon(Monitor *mon, const QObject *data) { QDict *qdict; qdict = qobject_to_qdict(data); + if (!qdict_haskey(qdict, "actual")) + return; - monitor_printf(mon, "balloon: actual=%" PRId64 "\n", - qdict_get_int(qdict, "balloon") >> 20); + monitor_printf(mon, "balloon: actual=%" PRId64, + qdict_get_int(qdict, "actual") >> 20); + qdict_iter(qdict, print_balloon_stat, mon); + monitor_printf(mon, "\n"); } /** @@ -2102,21 +2086,48 @@ static void monitor_print_balloon(Monitor *mon, const QObject *data) * * Return a QDict with the following information: * - * - "balloon": current balloon value in bytes + * - "actual": current balloon value in bytes + * The following fields may or may not be present: + * - "mem_swapped_in": Amount of memory swapped in (bytes) + * - "mem_swapped_out": Amount of memory swapped out (bytes) + * - "major_page_faults": Number of major faults + * - "minor_page_faults": Number of minor faults + * - "free_mem": Total amount of free and unused memory (bytes) + * - "total_mem": Total amount of available memory (bytes) * * Example: * - * { "balloon": 1073741824 } + * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0, + * "major_page_faults": 142, "minor_page_faults": 239245, + * "free_mem": 1014185984, "total_mem": 1044668416 } */ static void do_info_balloon(Monitor *mon, QObject **ret_data) { - ram_addr_t actual; + if (kvm_enabled() && !kvm_has_sync_mmu()) { + qemu_error_new(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon"); + return; + } + + *ret_data = qemu_balloon_status(); + if (*ret_data == NULL) + qemu_error_new(QERR_DEVICE_NOT_ACTIVE, "balloon"); +} - actual = balloon_get_value(); - if (actual != 0) { - *ret_data = qobject_from_jsonf("{ 'balloon': %" PRId64 "}", - (int64_t) actual); +/** + * do_balloon(): Request VM to change its memory allocation + */ +static void do_balloon(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + int ret; + + if (kvm_enabled() && !kvm_has_sync_mmu()) { + qemu_error_new(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon"); + return; } + + ret = qemu_balloon(qdict_get_int(qdict, "value")); + if (ret == 0) + qemu_error_new(QERR_DEVICE_NOT_ACTIVE, "balloon"); } static qemu_acl *find_acl(Monitor *mon, const char *name) diff --git a/monitor.h b/monitor.h index 6ed117a..f7d8780 100644 --- a/monitor.h +++ b/monitor.h @@ -32,6 +32,7 @@ void monitor_resume(Monitor *mon); void monitor_read_bdrv_key_start(Monitor *mon, BlockDriverState *bs, BlockDriverCompletionFunc *completion_cb, void *opaque); +void monitor_print_balloon(Monitor *mon, const QObject *data); int monitor_get_fd(Monitor *mon, const char *fdname); diff --git a/vl.c b/vl.c index 8be3648..029e572 100644 --- a/vl.c +++ b/vl.c @@ -362,17 +362,21 @@ void qemu_add_balloon_handler(QEMUBalloonEvent *func, void *opaque) qemu_balloon_event_opaque = opaque; } -void qemu_balloon(ram_addr_t target) +int qemu_balloon(ram_addr_t target) { - if (qemu_balloon_event) + if (qemu_balloon_event) { qemu_balloon_event(qemu_balloon_event_opaque, target); + return 1; + } else { + return 0; + } } -ram_addr_t qemu_balloon_status(void) +QObject *qemu_balloon_status(void) { if (qemu_balloon_event) return qemu_balloon_event(qemu_balloon_event_opaque, 0); - return 0; + return NULL; } /***********************************************************/ -- Thanks, Adam