mirror of https://github.com/proxmox/mirror_qemu
275 lines
7.6 KiB
C
275 lines
7.6 KiB
C
/*
|
|
* Virtio Balloon Device
|
|
*
|
|
* Copyright IBM, Corp. 2008
|
|
* Copyright (C) 2011 Red Hat, Inc.
|
|
* Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
|
|
*
|
|
* Authors:
|
|
* Anthony Liguori <aliguori@us.ibm.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2. See
|
|
* the COPYING file in the top-level directory.
|
|
*
|
|
*/
|
|
|
|
#include "qemu/iov.h"
|
|
#include "qemu-common.h"
|
|
#include "virtio.h"
|
|
#include "pc.h"
|
|
#include "cpu.h"
|
|
#include "sysemu/balloon.h"
|
|
#include "virtio-balloon.h"
|
|
#include "sysemu/kvm.h"
|
|
#include "exec/address-spaces.h"
|
|
|
|
#if defined(__linux__)
|
|
#include <sys/mman.h>
|
|
#endif
|
|
|
|
typedef struct VirtIOBalloon
|
|
{
|
|
VirtIODevice vdev;
|
|
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;
|
|
DeviceState *qdev;
|
|
} VirtIOBalloon;
|
|
|
|
static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
|
|
{
|
|
return (VirtIOBalloon *)vdev;
|
|
}
|
|
|
|
static void balloon_page(void *addr, int deflate)
|
|
{
|
|
#if defined(__linux__)
|
|
if (!kvm_enabled() || kvm_has_sync_mmu())
|
|
qemu_madvise(addr, TARGET_PAGE_SIZE,
|
|
deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* reset_stats - Mark all items in the stats array as unset
|
|
*
|
|
* This function needs to be called at device intialization and before
|
|
* before updating to a set of newly-generated stats. This will ensure that no
|
|
* stale values stick around in case the guest reports a subset of the supported
|
|
* statistics.
|
|
*/
|
|
static inline void reset_stats(VirtIOBalloon *dev)
|
|
{
|
|
int i;
|
|
for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
|
|
}
|
|
|
|
static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
|
|
{
|
|
VirtIOBalloon *s = to_virtio_balloon(vdev);
|
|
VirtQueueElement elem;
|
|
MemoryRegionSection section;
|
|
|
|
while (virtqueue_pop(vq, &elem)) {
|
|
size_t offset = 0;
|
|
uint32_t pfn;
|
|
|
|
while (iov_to_buf(elem.out_sg, elem.out_num, offset, &pfn, 4) == 4) {
|
|
ram_addr_t pa;
|
|
ram_addr_t addr;
|
|
|
|
pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT;
|
|
offset += 4;
|
|
|
|
/* FIXME: remove get_system_memory(), but how? */
|
|
section = memory_region_find(get_system_memory(), pa, 1);
|
|
if (!section.size || !memory_region_is_ram(section.mr))
|
|
continue;
|
|
|
|
/* Using memory_region_get_ram_ptr is bending the rules a bit, but
|
|
should be OK because we only want a single page. */
|
|
addr = section.offset_within_region;
|
|
balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
|
|
!!(vq == s->dvq));
|
|
}
|
|
|
|
virtqueue_push(vq, &elem, offset);
|
|
virtio_notify(vdev, 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;
|
|
}
|
|
|
|
/* Initialize the stats to get rid of any stale values. This is only
|
|
* needed to handle the case where a guest supports fewer stats than it
|
|
* used to (ie. it has booted into an old kernel).
|
|
*/
|
|
reset_stats(s);
|
|
|
|
while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
|
|
== 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;
|
|
}
|
|
|
|
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
|
|
{
|
|
VirtIOBalloon *dev = to_virtio_balloon(vdev);
|
|
struct virtio_balloon_config config;
|
|
|
|
config.num_pages = cpu_to_le32(dev->num_pages);
|
|
config.actual = cpu_to_le32(dev->actual);
|
|
|
|
memcpy(config_data, &config, 8);
|
|
}
|
|
|
|
static void virtio_balloon_set_config(VirtIODevice *vdev,
|
|
const uint8_t *config_data)
|
|
{
|
|
VirtIOBalloon *dev = to_virtio_balloon(vdev);
|
|
struct virtio_balloon_config config;
|
|
uint32_t oldactual = dev->actual;
|
|
memcpy(&config, config_data, 8);
|
|
dev->actual = le32_to_cpu(config.actual);
|
|
if (dev->actual != oldactual) {
|
|
qemu_balloon_changed(ram_size -
|
|
(dev->actual << VIRTIO_BALLOON_PFN_SHIFT));
|
|
}
|
|
}
|
|
|
|
static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
|
|
{
|
|
f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
|
|
return f;
|
|
}
|
|
|
|
static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
|
|
{
|
|
VirtIOBalloon *dev = opaque;
|
|
|
|
#if 0
|
|
/* Disable guest-provided stats for now. For more details please check:
|
|
* https://bugzilla.redhat.com/show_bug.cgi?id=623903
|
|
*
|
|
* If you do enable it (which is probably not going to happen as we
|
|
* need a new command for it), remember that you also need to fill the
|
|
* appropriate members of the BalloonInfo structure so that the stats
|
|
* are returned to the client.
|
|
*/
|
|
if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) {
|
|
virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset);
|
|
virtio_notify(&dev->vdev, dev->svq);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
/* Stats are not supported. Clear out any stale values that might
|
|
* have been set by a more featureful guest kernel.
|
|
*/
|
|
reset_stats(dev);
|
|
|
|
info->actual = ram_size - ((uint64_t) dev->actual <<
|
|
VIRTIO_BALLOON_PFN_SHIFT);
|
|
}
|
|
|
|
static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
|
|
{
|
|
VirtIOBalloon *dev = opaque;
|
|
|
|
if (target > ram_size) {
|
|
target = ram_size;
|
|
}
|
|
if (target) {
|
|
dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
|
|
virtio_notify_config(&dev->vdev);
|
|
}
|
|
}
|
|
|
|
static void virtio_balloon_save(QEMUFile *f, void *opaque)
|
|
{
|
|
VirtIOBalloon *s = opaque;
|
|
|
|
virtio_save(&s->vdev, f);
|
|
|
|
qemu_put_be32(f, s->num_pages);
|
|
qemu_put_be32(f, s->actual);
|
|
}
|
|
|
|
static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
|
|
{
|
|
VirtIOBalloon *s = opaque;
|
|
int ret;
|
|
|
|
if (version_id != 1)
|
|
return -EINVAL;
|
|
|
|
ret = virtio_load(&s->vdev, f);
|
|
if (ret) {
|
|
return ret;
|
|
}
|
|
|
|
s->num_pages = qemu_get_be32(f);
|
|
s->actual = qemu_get_be32(f);
|
|
return 0;
|
|
}
|
|
|
|
VirtIODevice *virtio_balloon_init(DeviceState *dev)
|
|
{
|
|
VirtIOBalloon *s;
|
|
int ret;
|
|
|
|
s = (VirtIOBalloon *)virtio_common_init("virtio-balloon",
|
|
VIRTIO_ID_BALLOON,
|
|
8, sizeof(VirtIOBalloon));
|
|
|
|
s->vdev.get_config = virtio_balloon_get_config;
|
|
s->vdev.set_config = virtio_balloon_set_config;
|
|
s->vdev.get_features = virtio_balloon_get_features;
|
|
|
|
ret = qemu_add_balloon_handler(virtio_balloon_to_target,
|
|
virtio_balloon_stat, s);
|
|
if (ret < 0) {
|
|
virtio_cleanup(&s->vdev);
|
|
return NULL;
|
|
}
|
|
|
|
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);
|
|
|
|
reset_stats(s);
|
|
|
|
s->qdev = dev;
|
|
register_savevm(dev, "virtio-balloon", -1, 1,
|
|
virtio_balloon_save, virtio_balloon_load, s);
|
|
|
|
return &s->vdev;
|
|
}
|
|
|
|
void virtio_balloon_exit(VirtIODevice *vdev)
|
|
{
|
|
VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev);
|
|
|
|
qemu_remove_balloon_handler(s);
|
|
unregister_savevm(s->qdev, "virtio-balloon", s);
|
|
virtio_cleanup(vdev);
|
|
}
|