diff options
| -rw-r--r-- | MAINTAINERS | 2 | ||||
| -rw-r--r-- | Makefile.objs | 1 | ||||
| -rw-r--r-- | backends/Makefile.objs | 4 | ||||
| -rw-r--r-- | backends/dbus-vmstate.c | 510 | ||||
| -rw-r--r-- | backends/trace-events | 7 | ||||
| -rw-r--r-- | docs/interop/dbus-vmstate.rst | 74 | ||||
| -rw-r--r-- | docs/interop/dbus.rst | 5 | ||||
| -rw-r--r-- | docs/interop/index.rst | 1 |
8 files changed, 604 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index e2e879e733..b6744bf78e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2209,9 +2209,11 @@ F: qapi/migration.json D-Bus M: Marc-André Lureau <marcandre.lureau@redhat.com> S: Maintained +F: backends/dbus-vmstate.c F: util/dbus.c F: include/qemu/dbus.h F: docs/interop/dbus.rst +F: docs/interop/dbus-vmstate.rst Seccomp M: Eduardo Otubo <otubo@redhat.com> diff --git a/Makefile.objs b/Makefile.objs index 02bf5ce11d..7c1e50f9d6 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -128,6 +128,7 @@ vhost-user-gpu-obj-y = contrib/vhost-user-gpu/ trace-events-subdirs = trace-events-subdirs += accel/kvm trace-events-subdirs += accel/tcg +trace-events-subdirs += backends trace-events-subdirs += crypto trace-events-subdirs += monitor ifeq ($(CONFIG_USER_ONLY),y) diff --git a/backends/Makefile.objs b/backends/Makefile.objs index f0691116e8..28a847cd57 100644 --- a/backends/Makefile.objs +++ b/backends/Makefile.objs @@ -17,3 +17,7 @@ endif common-obj-$(call land,$(CONFIG_VHOST_USER),$(CONFIG_VIRTIO)) += vhost-user.o common-obj-$(CONFIG_LINUX) += hostmem-memfd.o + +common-obj-$(CONFIG_GIO) += dbus-vmstate.o +dbus-vmstate.o-cflags = $(GIO_CFLAGS) +dbus-vmstate.o-libs = $(GIO_LIBS) diff --git a/backends/dbus-vmstate.c b/backends/dbus-vmstate.c new file mode 100644 index 0000000000..56b482a7d6 --- /dev/null +++ b/backends/dbus-vmstate.c @@ -0,0 +1,510 @@ +/* + * QEMU dbus-vmstate + * + * Copyright (C) 2019 Red Hat Inc + * + * Authors: + * Marc-André Lureau <marcandre.lureau@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/units.h" +#include "qemu/dbus.h" +#include "qemu/error-report.h" +#include "qapi/error.h" +#include "qom/object_interfaces.h" +#include "qapi/qmp/qerror.h" +#include "migration/vmstate.h" +#include "trace.h" + +typedef struct DBusVMState DBusVMState; +typedef struct DBusVMStateClass DBusVMStateClass; + +#define TYPE_DBUS_VMSTATE "dbus-vmstate" +#define DBUS_VMSTATE(obj) \ + OBJECT_CHECK(DBusVMState, (obj), TYPE_DBUS_VMSTATE) +#define DBUS_VMSTATE_GET_CLASS(obj) \ + OBJECT_GET_CLASS(DBusVMStateClass, (obj), TYPE_DBUS_VMSTATE) +#define DBUS_VMSTATE_CLASS(klass) \ + OBJECT_CLASS_CHECK(DBusVMStateClass, (klass), TYPE_DBUS_VMSTATE) + +struct DBusVMStateClass { + ObjectClass parent_class; +}; + +struct DBusVMState { + Object parent; + + GDBusConnection *bus; + char *dbus_addr; + char *id_list; + + uint32_t data_size; + uint8_t *data; +}; + +static const GDBusPropertyInfo vmstate_property_info[] = { + { -1, (char *) "Id", (char *) "s", + G_DBUS_PROPERTY_INFO_FLAGS_READABLE, NULL }, +}; + +static const GDBusPropertyInfo * const vmstate_property_info_pointers[] = { + &vmstate_property_info[0], + NULL +}; + +static const GDBusInterfaceInfo vmstate1_interface_info = { + -1, + (char *) "org.qemu.VMState1", + (GDBusMethodInfo **) NULL, + (GDBusSignalInfo **) NULL, + (GDBusPropertyInfo **) &vmstate_property_info_pointers, + NULL, +}; + +#define DBUS_VMSTATE_SIZE_LIMIT (1 * MiB) + +static GHashTable * +get_id_list_set(DBusVMState *self) +{ + g_auto(GStrv) ids = NULL; + g_autoptr(GHashTable) set = NULL; + int i; + + if (!self->id_list) { + return NULL; + } + + ids = g_strsplit(self->id_list, ",", -1); + set = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL); + for (i = 0; ids[i]; i++) { + g_hash_table_add(set, ids[i]); + ids[i] = NULL; + } + + return g_steal_pointer(&set); +} + +static GHashTable * +dbus_get_proxies(DBusVMState *self, GError **err) +{ + g_autoptr(GHashTable) proxies = NULL; + g_autoptr(GHashTable) ids = NULL; + g_auto(GStrv) names = NULL; + Error *error = NULL; + size_t i; + + ids = get_id_list_set(self); + proxies = g_hash_table_new_full(g_str_hash, g_str_equal, + g_free, g_object_unref); + + names = qemu_dbus_get_queued_owners(self->bus, "org.qemu.VMState1", &error); + if (!names) { + g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED, "%s", + error_get_pretty(error)); + error_free(error); + return NULL; + } + + for (i = 0; names[i]; i++) { + g_autoptr(GDBusProxy) proxy = NULL; + g_autoptr(GVariant) result = NULL; + g_autofree char *id = NULL; + size_t size; + + proxy = g_dbus_proxy_new_sync(self->bus, G_DBUS_PROXY_FLAGS_NONE, + (GDBusInterfaceInfo *) &vmstate1_interface_info, + names[i], + "/org/qemu/VMState1", + "org.qemu.VMState1", + NULL, err); + if (!proxy) { + return NULL; + } + + result = g_dbus_proxy_get_cached_property(proxy, "Id"); + if (!result) { + g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED, + "VMState Id property is missing."); + return NULL; + } + + id = g_variant_dup_string(result, &size); + if (ids && !g_hash_table_remove(ids, id)) { + g_clear_pointer(&id, g_free); + g_clear_object(&proxy); + continue; + } + if (size == 0 || size >= 256) { + g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED, + "VMState Id '%s' is invalid.", id); + return NULL; + } + + if (!g_hash_table_insert(proxies, id, proxy)) { + g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED, + "Duplicated VMState Id '%s'", id); + return NULL; + } + id = NULL; + proxy = NULL; + + g_clear_pointer(&result, g_variant_unref); + } + + if (ids) { + g_autofree char **left = NULL; + + left = (char **)g_hash_table_get_keys_as_array(ids, NULL); + if (*left) { + g_autofree char *leftids = g_strjoinv(",", left); + g_set_error(err, G_IO_ERROR, G_IO_ERROR_FAILED, + "Required VMState Id are missing: %s", leftids); + return NULL; + } + } + + return g_steal_pointer(&proxies); +} + +static int +dbus_load_state_proxy(GDBusProxy *proxy, const uint8_t *data, size_t size) +{ + g_autoptr(GError) err = NULL; + g_autoptr(GVariant) result = NULL; + g_autoptr(GVariant) value = NULL; + + value = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE, + data, size, sizeof(char)); + result = g_dbus_proxy_call_sync(proxy, "Load", + g_variant_new("(@ay)", + g_steal_pointer(&value)), + G_DBUS_CALL_FLAGS_NO_AUTO_START, + -1, NULL, &err); + if (!result) { + error_report("%s: Failed to Load: %s", __func__, err->message); + return -1; + } + + return 0; +} + +static int dbus_vmstate_post_load(void *opaque, int version_id) +{ + DBusVMState *self = DBUS_VMSTATE(opaque); + g_autoptr(GInputStream) m = NULL; + g_autoptr(GDataInputStream) s = NULL; + g_autoptr(GError) err = NULL; + g_autoptr(GHashTable) proxies = NULL; + uint32_t nelem; + + trace_dbus_vmstate_post_load(version_id); + + proxies = dbus_get_proxies(self, &err); + if (!proxies) { + error_report("%s: Failed to get proxies: %s", __func__, err->message); + return -1; + } + + m = g_memory_input_stream_new_from_data(self->data, self->data_size, NULL); + s = g_data_input_stream_new(m); + g_data_input_stream_set_byte_order(s, G_DATA_STREAM_BYTE_ORDER_BIG_ENDIAN); + + nelem = g_data_input_stream_read_uint32(s, NULL, &err); + if (err) { + goto error; + } + + while (nelem > 0) { + GDBusProxy *proxy = NULL; + uint32_t len; + gsize bytes_read, avail; + char id[256]; + + len = g_data_input_stream_read_uint32(s, NULL, &err); + if (err) { + goto error; + } + if (len >= 256) { + error_report("%s: Invalid DBus vmstate proxy name %u", + __func__, len); + return -1; + } + if (!g_input_stream_read_all(G_INPUT_STREAM(s), id, len, + &bytes_read, NULL, &err)) { + goto error; + } + g_return_val_if_fail(bytes_read == len, -1); + id[len] = 0; + + trace_dbus_vmstate_loading(id); + + proxy = g_hash_table_lookup(proxies, id); + if (!proxy) { + error_report("%s: Failed to find proxy Id '%s'", __func__, id); + return -1; + } + + len = g_data_input_stream_read_uint32(s, NULL, &err); + avail = g_buffered_input_stream_get_available( + G_BUFFERED_INPUT_STREAM(s)); + + if (len > DBUS_VMSTATE_SIZE_LIMIT || len > avail) { + error_report("%s: Invalid vmstate size: %u", __func__, len); + return -1; + } + + if (dbus_load_state_proxy(proxy, + g_buffered_input_stream_peek_buffer(G_BUFFERED_INPUT_STREAM(s), + NULL), + len) < 0) { + error_report("%s: Failed to restore Id '%s'", __func__, id); + return -1; + } + + if (!g_seekable_seek(G_SEEKABLE(s), len, G_SEEK_CUR, NULL, &err)) { + goto error; + } + + nelem -= 1; + } + + return 0; + +error: + error_report("%s: Failed to read from stream: %s", __func__, err->message); + return -1; +} + +static void +dbus_save_state_proxy(gpointer key, + gpointer value, + gpointer user_data) +{ + GDataOutputStream *s = user_data; + const char *id = key; + GDBusProxy *proxy = value; + g_autoptr(GVariant) result = NULL; + g_autoptr(GVariant) child = NULL; + g_autoptr(GError) err = NULL; + const uint8_t *data; + gsize size; + + trace_dbus_vmstate_saving(id); + + result = g_dbus_proxy_call_sync(proxy, "Save", + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START, + -1, NULL, &err); + if (!result) { + error_report("%s: Failed to Save: %s", __func__, err->message); + return; + } + + child = g_variant_get_child_value(result, 0); + data = g_variant_get_fixed_array(child, &size, sizeof(char)); + if (!data) { + error_report("%s: Failed to Save: not a byte array", __func__); + return; + } + if (size > DBUS_VMSTATE_SIZE_LIMIT) { + error_report("%s: Too large vmstate data to save: %zu", + __func__, (size_t)size); + return; + } + + if (!g_data_output_stream_put_uint32(s, strlen(id), NULL, &err) || + !g_data_output_stream_put_string(s, id, NULL, &err) || + !g_data_output_stream_put_uint32(s, size, NULL, &err) || + !g_output_stream_write_all(G_OUTPUT_STREAM(s), + data, size, NULL, NULL, &err)) { + error_report("%s: Failed to write to stream: %s", + __func__, err->message); + } +} + +static int dbus_vmstate_pre_save(void *opaque) +{ + DBusVMState *self = DBUS_VMSTATE(opaque); + g_autoptr(GOutputStream) m = NULL; + g_autoptr(GDataOutputStream) s = NULL; + g_autoptr(GHashTable) proxies = NULL; + g_autoptr(GError) err = NULL; + + trace_dbus_vmstate_pre_save(); + + proxies = dbus_get_proxies(self, &err); + if (!proxies) { + error_report("%s: Failed to get proxies: %s", __func__, err->message); + return -1; + } + + m = g_memory_output_stream_new_resizable(); + s = g_data_output_stream_new(m); + g_data_output_stream_set_byte_order(s, G_DATA_STREAM_BYTE_ORDER_BIG_ENDIAN); + + if (!g_data_output_stream_put_uint32(s, g_hash_table_size(proxies), + NULL, &err)) { + error_report("%s: Failed to write to stream: %s", + __func__, err->message); + return -1; + } + + g_hash_table_foreach(proxies, dbus_save_state_proxy, s); + + if (g_memory_output_stream_get_size(G_MEMORY_OUTPUT_STREAM(m)) + > UINT32_MAX) { + error_report("%s: DBus vmstate buffer is too large", __func__); + return -1; + } + + if (!g_output_stream_close(G_OUTPUT_STREAM(m), NULL, &err)) { + error_report("%s: Failed to close stream: %s", __func__, err->message); + return -1; + } + + g_free(self->data); + self->data_size = + g_memory_output_stream_get_size(G_MEMORY_OUTPUT_STREAM(m)); + self->data = + g_memory_output_stream_steal_data(G_MEMORY_OUTPUT_STREAM(m)); + + return 0; +} + +static const VMStateDescription dbus_vmstate = { + .name = TYPE_DBUS_VMSTATE, + .version_id = 0, + .pre_save = dbus_vmstate_pre_save, + .post_load = dbus_vmstate_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT32(data_size, DBusVMState), + VMSTATE_VBUFFER_ALLOC_UINT32(data, DBusVMState, 0, 0, data_size), + VMSTATE_END_OF_LIST() + } +}; + +static void +dbus_vmstate_complete(UserCreatable *uc, Error **errp) +{ + DBusVMState *self = DBUS_VMSTATE(uc); + g_autoptr(GError) err = NULL; + + if (!object_resolve_path_type("", TYPE_DBUS_VMSTATE, NULL)) { + error_setg(errp, "There is already an instance of %s", + TYPE_DBUS_VMSTATE); + return; + } + + if (!self->dbus_addr) { + error_setg(errp, QERR_MISSING_PARAMETER, "addr"); + return; + } + + self->bus = g_dbus_connection_new_for_address_sync(self->dbus_addr, + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT | + G_DBUS_CONNECTION_FLAGS_MESSAGE_BUS_CONNECTION, + NULL, NULL, &err); + if (err) { + error_setg(errp, "failed to connect to DBus: '%s'", err->message); + return; + } + + if (vmstate_register(VMSTATE_IF(self), -1, &dbus_vmstate, self) < 0) { + error_setg(errp, "Failed to register vmstate"); + } +} + +static void +dbus_vmstate_finalize(Object *o) +{ + DBusVMState *self = DBUS_VMSTATE(o); + + vmstate_unregister(VMSTATE_IF(self), &dbus_vmstate, self); + + g_clear_object(&self->bus); + g_free(self->dbus_addr); + g_free(self->id_list); + g_free(self->data); +} + +static char * +get_dbus_addr(Object *o, Error **errp) +{ + DBusVMState *self = DBUS_VMSTATE(o); + + return g_strdup(self->dbus_addr); +} + +static void +set_dbus_addr(Object *o, const char *str, Error **errp) +{ + DBusVMState *self = DBUS_VMSTATE(o); + + g_free(self->dbus_addr); + self->dbus_addr = g_strdup(str); +} + +static char * +get_id_list(Object *o, Error **errp) +{ + DBusVMState *self = DBUS_VMSTATE(o); + + return g_strdup(self->id_list); +} + +static void +set_id_list(Object *o, const char *str, Error **errp) +{ + DBusVMState *self = DBUS_VMSTATE(o); + + g_free(self->id_list); + self->id_list = g_strdup(str); +} + +static char * +dbus_vmstate_get_id(VMStateIf *vmif) +{ + return g_strdup(TYPE_DBUS_VMSTATE); +} + +static void +dbus_vmstate_class_init(ObjectClass *oc, void *data) +{ + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); + VMStateIfClass *vc = VMSTATE_IF_CLASS(oc); + + ucc->complete = dbus_vmstate_complete; + vc->get_id = dbus_vmstate_get_id; + + object_class_property_add_str(oc, "addr", + get_dbus_addr, set_dbus_addr, + &error_abort); + object_class_property_add_str(oc, "id-list", + get_id_list, set_id_list, + &error_abort); +} + +static const TypeInfo dbus_vmstate_info = { + .name = TYPE_DBUS_VMSTATE, + .parent = TYPE_OBJECT, + .instance_size = sizeof(DBusVMState), + .instance_finalize = dbus_vmstate_finalize, + .class_size = sizeof(DBusVMStateClass), + .class_init = dbus_vmstate_class_init, + .interfaces = (InterfaceInfo[]) { + { TYPE_USER_CREATABLE }, + { TYPE_VMSTATE_IF }, + { } + } +}; + +static void +register_types(void) +{ + type_register_static(&dbus_vmstate_info); +} + +type_init(register_types); diff --git a/backends/trace-events b/backends/trace-events new file mode 100644 index 0000000000..59058f7630 --- /dev/null +++ b/backends/trace-events @@ -0,0 +1,7 @@ +# See docs/devel/tracing.txt for syntax documentation. + +# dbus-vmstate.c +dbus_vmstate_pre_save(void) +dbus_vmstate_post_load(int version_id) "version_id: %d" +dbus_vmstate_loading(const char *id) "id: %s" +dbus_vmstate_saving(const char *id) "id: %s" diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst new file mode 100644 index 0000000000..1d719c1c60 --- /dev/null +++ b/docs/interop/dbus-vmstate.rst @@ -0,0 +1,74 @@ +============= +D-Bus VMState +============= + +Introduction +============ + +The QEMU dbus-vmstate object's aim is to migrate helpers' data running +on a QEMU D-Bus bus. (refer to the :doc:`dbus` document for +some recommendations on D-Bus usage) + +Upon migration, QEMU will go through the queue of +``org.qemu.VMState1`` D-Bus name owners and query their ``Id``. It +must be unique among the helpers. + +It will then save arbitrary data of each Id to be transferred in the +migration stream and restored/loaded at the corresponding destination +helper. + +For now, the data amount to be transferred is arbitrarily limited to +1Mb. The state must be saved quickly (a fraction of a second). (D-Bus +imposes a time limit on reply anyway, and migration would fail if data +isn't given quickly enough.) + +dbus-vmstate object can be configured with the expected list of +helpers by setting its ``id-list`` property, with a comma-separated +``Id`` list. + +Interface +========= + +On object path ``/org/qemu/VMState1``, the following +``org.qemu.VMState1`` interface should be implemented: + +.. code:: xml + + <interface name="org.qemu.VMState1"> + <property name="Id" type="s" access="read"/> + <method name="Load"> + <arg type="ay" name="data" direction="in"/> + </method> + <method name="Save"> + <arg type="ay" name="data" direction="out"/> + </method> + </interface> + +"Id" property +------------- + +A string that identifies the helper uniquely. (maximum 256 bytes +including terminating NUL byte) + +.. note:: + + The helper ID namespace is a separate namespace. In particular, it is not + related to QEMU "id" used in -object/-device objects. + +Load(in u8[] bytes) method +-------------------------- + +The method called on destination with the state to restore. + +The helper may be initially started in a waiting state (with +an --incoming argument for example), and it may resume on success. + +An error may be returned to the caller. + +Save(out u8[] bytes) method +--------------------------- + +The method called on the source to get the current state to be +migrated. The helper should continue to run normally. + +An error may be returned to the caller. diff --git a/docs/interop/dbus.rst b/docs/interop/dbus.rst index ef80d4204d..76a5bde625 100644 --- a/docs/interop/dbus.rst +++ b/docs/interop/dbus.rst @@ -103,3 +103,8 @@ https://dbus.freedesktop.org/doc/dbus-api-design.html The "org.qemu.*" prefix is reserved for services implemented & distributed by the QEMU project. + +QEMU Interfaces +=============== + +:doc:`dbus-vmstate` diff --git a/docs/interop/index.rst b/docs/interop/index.rst index ded134ea75..049387ac6d 100644 --- a/docs/interop/index.rst +++ b/docs/interop/index.rst @@ -14,6 +14,7 @@ Contents: bitmaps dbus + dbus-vmstate live-block-operations pr-helper qemu-ga |