aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Virtio Block Device |
| 3 | * |
| 4 | * Copyright IBM, Corp. 2008 |
| 5 | * |
| 6 | * Authors: |
| 7 | * Anthony Liguori <aliguori@us.ibm.com> |
| 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 10 | * the COPYING file in the top-level directory. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | #include "qemu-common.h" |
| 15 | #include "virtio.h" |
| 16 | #include "pc.h" |
| 17 | #include "sysemu.h" |
| 18 | #include "cpu.h" |
| 19 | #include "balloon.h" |
| 20 | #include "virtio-balloon.h" |
| 21 | #include "kvm.h" |
| 22 | |
| 23 | #if defined(__linux__) |
| 24 | #include <sys/mman.h> |
| 25 | #endif |
| 26 | |
| 27 | typedef struct VirtIOBalloon |
| 28 | { |
| 29 | VirtIODevice vdev; |
| 30 | VirtQueue *ivq, *dvq; |
| 31 | uint32_t num_pages; |
| 32 | uint32_t actual; |
| 33 | } VirtIOBalloon; |
| 34 | |
| 35 | static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev) |
| 36 | { |
| 37 | return (VirtIOBalloon *)vdev; |
| 38 | } |
| 39 | |
| 40 | static void balloon_page(void *addr, int deflate) |
| 41 | { |
| 42 | #if defined(__linux__) |
| 43 | if (!kvm_enabled() || kvm_has_sync_mmu()) |
| 44 | madvise(addr, TARGET_PAGE_SIZE, |
| 45 | deflate ? MADV_WILLNEED : MADV_DONTNEED); |
| 46 | #endif |
| 47 | } |
| 48 | |
| 49 | /* FIXME: once we do a virtio refactoring, this will get subsumed into common |
| 50 | * code */ |
| 51 | static size_t memcpy_from_iovector(void *data, size_t offset, size_t size, |
| 52 | struct iovec *iov, int iovlen) |
| 53 | { |
| 54 | int i; |
| 55 | uint8_t *ptr = data; |
| 56 | size_t iov_off = 0; |
| 57 | size_t data_off = 0; |
| 58 | |
| 59 | for (i = 0; i < iovlen && size; i++) { |
| 60 | if (offset < (iov_off + iov[i].iov_len)) { |
| 61 | size_t len = MIN((iov_off + iov[i].iov_len) - offset , size); |
| 62 | |
| 63 | memcpy(ptr + data_off, iov[i].iov_base + (offset - iov_off), len); |
| 64 | |
| 65 | data_off += len; |
| 66 | offset += len; |
| 67 | size -= len; |
| 68 | } |
| 69 | |
| 70 | iov_off += iov[i].iov_len; |
| 71 | } |
| 72 | |
| 73 | return data_off; |
| 74 | } |
| 75 | |
| 76 | static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
| 77 | { |
| 78 | VirtIOBalloon *s = to_virtio_balloon(vdev); |
| 79 | VirtQueueElement elem; |
| 80 | |
| 81 | while (virtqueue_pop(vq, &elem)) { |
| 82 | size_t offset = 0; |
| 83 | uint32_t pfn; |
| 84 | |
| 85 | while (memcpy_from_iovector(&pfn, offset, 4, |
| 86 | elem.out_sg, elem.out_num) == 4) { |
Anthony Liguori | c227f09 | 2009-10-01 16:12:16 -0500 | [diff] [blame] | 87 | ram_addr_t pa; |
| 88 | ram_addr_t addr; |
aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 89 | |
Anthony Liguori | c227f09 | 2009-10-01 16:12:16 -0500 | [diff] [blame] | 90 | pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT; |
aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 91 | offset += 4; |
| 92 | |
| 93 | addr = cpu_get_physical_page_desc(pa); |
| 94 | if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM) |
| 95 | continue; |
| 96 | |
pbrook | 5c130f6 | 2009-04-10 14:29:45 +0000 | [diff] [blame] | 97 | /* Using qemu_get_ram_ptr is bending the rules a bit, but |
| 98 | should be OK because we only want a single page. */ |
| 99 | balloon_page(qemu_get_ram_ptr(addr), !!(vq == s->dvq)); |
aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | virtqueue_push(vq, &elem, offset); |
| 103 | virtio_notify(vdev, vq); |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) |
| 108 | { |
| 109 | VirtIOBalloon *dev = to_virtio_balloon(vdev); |
| 110 | struct virtio_balloon_config config; |
| 111 | |
| 112 | config.num_pages = cpu_to_le32(dev->num_pages); |
| 113 | config.actual = cpu_to_le32(dev->actual); |
| 114 | |
| 115 | memcpy(config_data, &config, 8); |
| 116 | } |
| 117 | |
| 118 | static void virtio_balloon_set_config(VirtIODevice *vdev, |
| 119 | const uint8_t *config_data) |
| 120 | { |
| 121 | VirtIOBalloon *dev = to_virtio_balloon(vdev); |
| 122 | struct virtio_balloon_config config; |
| 123 | memcpy(&config, config_data, 8); |
| 124 | dev->actual = config.actual; |
| 125 | } |
| 126 | |
| 127 | static uint32_t virtio_balloon_get_features(VirtIODevice *vdev) |
| 128 | { |
| 129 | return 0; |
| 130 | } |
| 131 | |
Anthony Liguori | c227f09 | 2009-10-01 16:12:16 -0500 | [diff] [blame] | 132 | static ram_addr_t virtio_balloon_to_target(void *opaque, ram_addr_t target) |
aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 133 | { |
| 134 | VirtIOBalloon *dev = opaque; |
| 135 | |
| 136 | if (target > ram_size) |
| 137 | target = ram_size; |
| 138 | |
| 139 | if (target) { |
| 140 | dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; |
| 141 | virtio_notify_config(&dev->vdev); |
| 142 | } |
| 143 | |
| 144 | return ram_size - (dev->actual << VIRTIO_BALLOON_PFN_SHIFT); |
| 145 | } |
| 146 | |
| 147 | static void virtio_balloon_save(QEMUFile *f, void *opaque) |
| 148 | { |
| 149 | VirtIOBalloon *s = opaque; |
| 150 | |
| 151 | virtio_save(&s->vdev, f); |
| 152 | |
| 153 | qemu_put_be32(f, s->num_pages); |
| 154 | qemu_put_be32(f, s->actual); |
| 155 | } |
| 156 | |
| 157 | static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) |
| 158 | { |
| 159 | VirtIOBalloon *s = opaque; |
| 160 | |
| 161 | if (version_id != 1) |
| 162 | return -EINVAL; |
| 163 | |
| 164 | virtio_load(&s->vdev, f); |
| 165 | |
| 166 | s->num_pages = qemu_get_be32(f); |
| 167 | s->actual = qemu_get_be32(f); |
| 168 | |
| 169 | return 0; |
| 170 | } |
| 171 | |
Paul Brook | 53c25ce | 2009-05-18 14:51:59 +0100 | [diff] [blame] | 172 | VirtIODevice *virtio_balloon_init(DeviceState *dev) |
aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 173 | { |
| 174 | VirtIOBalloon *s; |
| 175 | |
Paul Brook | 53c25ce | 2009-05-18 14:51:59 +0100 | [diff] [blame] | 176 | s = (VirtIOBalloon *)virtio_common_init("virtio-balloon", |
| 177 | VIRTIO_ID_BALLOON, |
| 178 | 8, sizeof(VirtIOBalloon)); |
aliguori | bd32208 | 2008-12-04 20:33:06 +0000 | [diff] [blame] | 179 | |
| 180 | s->vdev.get_config = virtio_balloon_get_config; |
| 181 | s->vdev.set_config = virtio_balloon_set_config; |
| 182 | s->vdev.get_features = virtio_balloon_get_features; |
| 183 | |
| 184 | s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output); |
| 185 | s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output); |
| 186 | |
| 187 | qemu_add_balloon_handler(virtio_balloon_to_target, s); |
| 188 | |
| 189 | register_savevm("virtio-balloon", -1, 1, virtio_balloon_save, virtio_balloon_load, s); |
Paul Brook | 2d72c57 | 2009-05-14 22:35:08 +0100 | [diff] [blame] | 190 | |
Paul Brook | 53c25ce | 2009-05-18 14:51:59 +0100 | [diff] [blame] | 191 | return &s->vdev; |
Paul Brook | 2d72c57 | 2009-05-14 22:35:08 +0100 | [diff] [blame] | 192 | } |