Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru> writes: > Add command to sync config from vhost-user backend to the device. It > may be helpful when VHOST_USER_SLAVE_CONFIG_CHANGE_MSG failed or not > triggered interrupt to the guest or just not available (not supported > by vhost-user server). > > Command result is racy if allow it during migration. Let's allow the > sync only in RUNNING state. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru> > --- > hw/block/vhost-user-blk.c | 1 + > hw/virtio/virtio-pci.c | 9 ++++++++ > include/hw/qdev-core.h | 3 +++ > qapi/qdev.json | 23 +++++++++++++++++++ > system/qdev-monitor.c | 48 +++++++++++++++++++++++++++++++++++++++ > 5 files changed, 84 insertions(+) > > diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c > index 091d2c6acf..2f301f380c 100644 > --- a/hw/block/vhost-user-blk.c > +++ b/hw/block/vhost-user-blk.c > @@ -588,6 +588,7 @@ static void vhost_user_blk_class_init(ObjectClass *klass, > void *data) > > device_class_set_props(dc, vhost_user_blk_properties); > dc->vmsd = &vmstate_vhost_user_blk; > + dc->sync_config = vhost_user_blk_sync_config; > set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); > vdc->realize = vhost_user_blk_device_realize; > vdc->unrealize = vhost_user_blk_device_unrealize; > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index b1d02f4b3d..0d91e8b5dc 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -2351,6 +2351,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, > Error **errp) > vpciklass->parent_dc_realize(qdev, errp); > } > > +static int virtio_pci_sync_config(DeviceState *dev, Error **errp) > +{ > + VirtIOPCIProxy *proxy = VIRTIO_PCI(dev); > + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); > + > + return qdev_sync_config(DEVICE(vdev), errp); > +} > + > static void virtio_pci_class_init(ObjectClass *klass, void *data) > { > DeviceClass *dc = DEVICE_CLASS(klass); > @@ -2367,6 +2375,7 @@ static void virtio_pci_class_init(ObjectClass *klass, > void *data) > device_class_set_parent_realize(dc, virtio_pci_dc_realize, > &vpciklass->parent_dc_realize); > rc->phases.hold = virtio_pci_bus_reset_hold; > + dc->sync_config = virtio_pci_sync_config; > } > > static const TypeInfo virtio_pci_info = { > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h > index 9228e96c87..87135bdcdf 100644 > --- a/include/hw/qdev-core.h > +++ b/include/hw/qdev-core.h > @@ -95,6 +95,7 @@ typedef void (*DeviceUnrealize)(DeviceState *dev); > typedef void (*DeviceReset)(DeviceState *dev); > typedef void (*BusRealize)(BusState *bus, Error **errp); > typedef void (*BusUnrealize)(BusState *bus); > +typedef int (*DeviceSyncConfig)(DeviceState *dev, Error **errp); > > /** > * struct DeviceClass - The base class for all devices. > @@ -162,6 +163,7 @@ struct DeviceClass { > DeviceReset reset; > DeviceRealize realize; > DeviceUnrealize unrealize; > + DeviceSyncConfig sync_config; > > /** > * @vmsd: device state serialisation description for > @@ -546,6 +548,7 @@ bool qdev_hotplug_allowed(DeviceState *dev, Error **errp); > */ > HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev); > void qdev_unplug(DeviceState *dev, Error **errp); > +int qdev_sync_config(DeviceState *dev, Error **errp); > void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev, > DeviceState *dev, Error **errp); > void qdev_machine_creation_done(void); > diff --git a/qapi/qdev.json b/qapi/qdev.json > index facaa0bc6a..fc5e125a45 100644 > --- a/qapi/qdev.json > +++ b/qapi/qdev.json > @@ -161,3 +161,26 @@ > ## > { 'event': 'DEVICE_UNPLUG_GUEST_ERROR', > 'data': { '*device': 'str', 'path': 'str' } } > + > +## > +# @device-sync-config: > +# > +# Synchronize device configuration from host to guest part. First, > +# copy the configuration from the host part (backend) to the guest > +# part (frontend). Then notify guest software that device > +# configuration changed.
Blank line here, please. > +# The command may be used to notify the guest about block device > +# capcity change. Currently only vhost-user-blk device supports > +# this. > +# > +# @id: the device's ID or QOM path > +# > +# Features: > +# > +# @unstable: The command is experimental. > +# > +# Since: 9.1 > +## > +{ 'command': 'device-sync-config', > + 'features': [ 'unstable' ], > + 'data': {'id': 'str'} } > diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c > index 264978aa40..47bfc0506e 100644 > --- a/system/qdev-monitor.c > +++ b/system/qdev-monitor.c > @@ -23,6 +23,7 @@ > #include "monitor/monitor.h" > #include "monitor/qdev.h" > #include "sysemu/arch_init.h" > +#include "sysemu/runstate.h" > #include "qapi/error.h" > #include "qapi/qapi-commands-qdev.h" > #include "qapi/qmp/dispatch.h" > @@ -971,6 +972,53 @@ void qmp_device_del(const char *id, Error **errp) > } > } > > +int qdev_sync_config(DeviceState *dev, Error **errp) > +{ > + DeviceClass *dc = DEVICE_GET_CLASS(dev); > + > + if (!dc->sync_config) { > + error_setg(errp, "device-sync-config is not supported for '%s'", > + object_get_typename(OBJECT(dev))); > + return -ENOTSUP; > + } > + > + return dc->sync_config(dev, errp); > +} > + > +void qmp_device_sync_config(const char *id, Error **errp) > +{ > + DeviceState *dev; > + > + /* > + * During migration there is a race between syncing`configuration and > + * migrating it (if migrate first, that target would get outdated > version), > + * so let's just not allow it. Wrap comment lines around column 70 for legibility, please. > + * > + * Moreover, let's not rely on setting up interrupts in paused > + * state, which may be a part of migration process. We discussed this in review of v3. You wanted to check whether the problem is real. Is it? > + */ > + > + if (migration_is_running()) { > + error_setg(errp, "Config synchronization is not allowed " > + "during migration"); > + return; > + } > + > + if (!runstate_is_running()) { > + error_setg(errp, "Config synchronization allowed only in '%s' state, > " Suggest a line break after errp, > + "current state is '%s'", RunState_str(RUN_STATE_RUNNING), > + RunState_str(runstate_get())); > + return; > + } > + > + dev = find_device_state(id, true, errp); > + if (!dev) { > + return; > + } > + > + qdev_sync_config(dev, errp); > +} > + > void hmp_device_add(Monitor *mon, const QDict *qdict) > { > Error *err = NULL;