diff options
Diffstat (limited to 'hw/virtio/virtio-balloon.c')
| -rw-r--r-- | hw/virtio/virtio-balloon.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 11fad86d64..e85d1c0d5c 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -615,6 +615,22 @@ virtio_balloon_free_page_report_notify(NotifierWithReturn *n, void *data) return 0; } +static size_t virtio_balloon_config_size(VirtIOBalloon *s) +{ + uint64_t features = s->host_features; + + if (s->qemu_4_0_config_size) { + return sizeof(struct virtio_balloon_config); + } + if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON)) { + return sizeof(struct virtio_balloon_config); + } + if (virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { + return offsetof(struct virtio_balloon_config, poison_val); + } + return offsetof(struct virtio_balloon_config, free_page_report_cmd_id); +} + static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) { VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); @@ -635,7 +651,7 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) } trace_virtio_balloon_get_config(config.num_pages, config.actual); - memcpy(config_data, &config, sizeof(struct virtio_balloon_config)); + memcpy(config_data, &config, virtio_balloon_config_size(dev)); } static int build_dimm_list(Object *obj, void *opaque) @@ -679,7 +695,7 @@ static void virtio_balloon_set_config(VirtIODevice *vdev, uint32_t oldactual = dev->actual; ram_addr_t vm_ram_size = get_current_ram_size(); - memcpy(&config, config_data, sizeof(struct virtio_balloon_config)); + memcpy(&config, config_data, virtio_balloon_config_size(dev)); dev->actual = le32_to_cpu(config.actual); if (dev->actual != oldactual) { qapi_event_send_balloon_change(vm_ram_size - @@ -766,7 +782,7 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp) int ret; virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON, - sizeof(struct virtio_balloon_config)); + virtio_balloon_config_size(s)); ret = qemu_add_balloon_handler(virtio_balloon_to_target, virtio_balloon_stat, s); @@ -897,6 +913,12 @@ static Property virtio_balloon_properties[] = { VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false), DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT, false), + /* QEMU 4.0 accidentally changed the config size even when free-page-hint + * is disabled, resulting in QEMU 3.1 migration incompatibility. This + * property retains this quirk for QEMU 4.1 machine types. + */ + DEFINE_PROP_BOOL("qemu-4-0-config-size", VirtIOBalloon, + qemu_4_0_config_size, false), DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD, IOThread *), DEFINE_PROP_END_OF_LIST(), |