--- /dev/null
+/*
+ * Virtio Block Device
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * 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-common.h"
+#include "virtio.h"
+#include "pc.h"
+#include "sysemu.h"
+#include "cpu.h"
+#include "balloon.h"
+#include "virtio-balloon.h"
+#include "kvm.h"
+
+#if defined(__linux__)
+#include <sys/mman.h>
+#endif
+
+typedef struct VirtIOBalloon
+{
+ VirtIODevice vdev;
+ VirtQueue *ivq, *dvq;
+ uint32_t num_pages;
+ uint32_t actual;
+} 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())
+ madvise(addr, TARGET_PAGE_SIZE,
+ deflate ? MADV_WILLNEED : 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)
+{
+ 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;
+}
+
+static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOBalloon *s = to_virtio_balloon(vdev);
+ VirtQueueElement elem;
+
+ 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) {
+ 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)
+ continue;
+
+ balloon_page(phys_ram_base + addr, !!(vq == s->dvq));
+ }
+
+ virtqueue_push(vq, &elem, offset);
+ virtio_notify(vdev, vq);
+ }
+}
+
+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;
+ memcpy(&config, config_data, 8);
+ dev->actual = config.actual;
+}
+
+static uint32_t virtio_balloon_get_features(VirtIODevice *vdev)
+{
+ return 0;
+}
+
+static ram_addr_t 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)
+{
+ 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;
+
+ if (version_id != 1)
+ return -EINVAL;
+
+ virtio_load(&s->vdev, f);
+
+ s->num_pages = qemu_get_be32(f);
+ s->actual = qemu_get_be32(f);
+
+ return 0;
+}
+
+void *virtio_balloon_init(PCIBus *bus)
+{
+ VirtIOBalloon *s;
+
+ s = (VirtIOBalloon *)virtio_init_pci(bus, "virtio-balloon",
+ 6900, 0x1002,
+ 0, VIRTIO_ID_BALLOON,
+ 0x05, 0x00, 0x00,
+ 8, sizeof(VirtIOBalloon));
+ if (s == NULL)
+ return NULL;
+
+ s->vdev.get_config = virtio_balloon_get_config;
+ s->vdev.set_config = virtio_balloon_set_config;
+ s->vdev.get_features = virtio_balloon_get_features;
+
+ s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
+ s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
+
+ qemu_add_balloon_handler(virtio_balloon_to_target, s);
+
+ register_savevm("virtio-balloon", -1, 1, virtio_balloon_save, virtio_balloon_load, s);
+
+ return &s->vdev;
+}
--- /dev/null
+/*
+ * Virtio Support
+ *
+ * Copyright IBM, Corp. 2007-2008
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ * Rusty Russell <rusty@rustcorp.com.au>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef _QEMU_VIRTIO_BALLOON_H
+#define _QEMU_VIRTIO_BALLOON_H
+
+#include "virtio.h"
+#include "pci.h"
+
+/* from Linux's linux/virtio_balloon.h */
+
+/* The ID for virtio_balloon */
+#define VIRTIO_ID_BALLOON 5
+
+/* The feature bitmap for virtio balloon */
+#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
+
+/* Size of a PFN in the balloon interface. */
+#define VIRTIO_BALLOON_PFN_SHIFT 12
+
+struct virtio_balloon_config
+{
+ /* Number of pages host wants Guest to give up. */
+ uint32_t num_pages;
+ /* Number of pages we've actually got in balloon. */
+ uint32_t actual;
+};
+
+void *virtio_balloon_init(PCIBus *bus);
+
+#endif
projects / qemu.git / commitdiff