/*
- * Virtio Block Device
+ * 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>
*
*/
+#include "qemu/iov.h"
#include "qemu-common.h"
#include "virtio.h"
#include "pc.h"
-#include "sysemu.h"
#include "cpu.h"
-#include "balloon.h"
+#include "sysemu/balloon.h"
#include "virtio-balloon.h"
-#include "kvm.h"
+#include "sysemu/kvm.h"
+#include "exec/address-spaces.h"
#if defined(__linux__)
#include <sys/mman.h>
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;
+ DeviceState *qdev;
} VirtIOBalloon;
static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
{
#if defined(__linux__)
if (!kvm_enabled() || kvm_has_sync_mmu())
- madvise(addr, TARGET_PAGE_SIZE,
- deflate ? MADV_WILLNEED : MADV_DONTNEED);
+ qemu_madvise(addr, TARGET_PAGE_SIZE,
+ deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
#endif
}
-/* 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,
- struct iovec *iov, int iovlen)
+/*
+ * 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;
- uint8_t *ptr = data;
- size_t iov_off = 0;
- size_t data_off = 0;
-
- for (i = 0; i < iovlen && size; i++) {
- if (offset < (iov_off + iov[i].iov_len)) {
- size_t len = MIN((iov_off + iov[i].iov_len) - offset , size);
-
- memcpy(ptr + data_off, iov[i].iov_base + (offset - iov_off), len);
-
- data_off += len;
- offset += len;
- size -= len;
- }
-
- iov_off += iov[i].iov_len;
- }
-
- return data_off;
+ 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 (memcpy_from_iovector(&pfn, offset, 4,
- elem.out_sg, elem.out_num) == 4) {
+ 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;
- addr = cpu_get_physical_page_desc(pa);
- if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM)
+ /* 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 qemu_get_ram_ptr is bending the rules a bit, but
+ /* Using memory_region_get_ram_ptr is bending the rules a bit, but
should be OK because we only want a single page. */
- balloon_page(qemu_get_ram_ptr(addr), !!(vq == s->dvq));
+ addr = section.offset_within_region;
+ balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
+ !!(vq == s->dvq));
}
virtqueue_push(vq, &elem, offset);
}
}
+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);
{
VirtIOBalloon *dev = to_virtio_balloon(vdev);
struct virtio_balloon_config config;
+ uint32_t oldactual = dev->actual;
memcpy(&config, config_data, 8);
- dev->actual = config.actual;
+ 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)
+static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
{
- return 0;
+ f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
+ return f;
}
-static ram_addr_t virtio_balloon_to_target(void *opaque, ram_addr_t target)
+static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
{
VirtIOBalloon *dev = opaque;
- if (target > ram_size)
- target = ram_size;
+#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);
}
-
- return ram_size - (dev->actual << VIRTIO_BALLOON_PFN_SHIFT);
}
static void virtio_balloon_save(QEMUFile *f, void *opaque)
static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
{
VirtIOBalloon *s = opaque;
+ int ret;
if (version_id != 1)
return -EINVAL;
- virtio_load(&s->vdev, f);
+ 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,
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);
- qemu_add_balloon_handler(virtio_balloon_to_target, s);
+ reset_stats(s);
- register_savevm("virtio-balloon", -1, 1, virtio_balloon_save, virtio_balloon_load, 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);
+}
projects / qemu.git / blobdiff