qemu/hw/core/qdev-properties-system.c
Kevin Wolf 8daea51095 block/qdev: Allow node name for drive properties
If a node name instead of a BlockBackend name is specified as the driver
for a guest device, an anonymous BlockBackend is created now.

The order of operations in release_drive() must be reversed in order to
avoid a use-after-free bug because now blk_detach_dev() frees the last
reference if an anonymous BlockBackend is used.

usb-storage uses a hack where it forwards its BlockBackend as a property
to another device that it internally creates. This hack must be updated
so that it doesn't drop its original BB before it can be passed to the
other device. This used to work because we always had the monitor
reference around, but with node-names the device reference is the only
one now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-07-13 13:28:00 +02:00

424 lines
11 KiB
C

/*
* qdev property parsing
* (parts specific for qemu-system-*)
*
* This file is based on code from hw/qdev-properties.c from
* commit 074a86fccd185616469dfcdc0e157f438aebba18,
* Copyright (c) Gerd Hoffmann <kraxel@redhat.com> and other contributors.
*
* 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 "net/net.h"
#include "hw/qdev.h"
#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
#include "sysemu/block-backend.h"
#include "sysemu/blockdev.h"
#include "hw/block/block.h"
#include "net/hub.h"
#include "qapi/visitor.h"
#include "sysemu/char.h"
#include "sysemu/iothread.h"
static void get_pointer(Object *obj, Visitor *v, Property *prop,
char *(*print)(void *ptr),
const char *name, Error **errp)
{
DeviceState *dev = DEVICE(obj);
void **ptr = qdev_get_prop_ptr(dev, prop);
char *p;
p = *ptr ? print(*ptr) : g_strdup("");
visit_type_str(v, name, &p, errp);
g_free(p);
}
static void set_pointer(Object *obj, Visitor *v, Property *prop,
void (*parse)(DeviceState *dev, const char *str,
void **ptr, const char *propname,
Error **errp),
const char *name, Error **errp)
{
DeviceState *dev = DEVICE(obj);
Error *local_err = NULL;
void **ptr = qdev_get_prop_ptr(dev, prop);
char *str;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
visit_type_str(v, name, &str, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (!*str) {
g_free(str);
*ptr = NULL;
return;
}
parse(dev, str, ptr, prop->name, errp);
g_free(str);
}
/* --- drive --- */
static void parse_drive(DeviceState *dev, const char *str, void **ptr,
const char *propname, Error **errp)
{
BlockBackend *blk;
bool blk_created = false;
blk = blk_by_name(str);
if (!blk) {
BlockDriverState *bs = bdrv_lookup_bs(NULL, str, NULL);
if (bs) {
blk = blk_new();
blk_insert_bs(blk, bs);
blk_created = true;
}
}
if (!blk) {
error_setg(errp, "Property '%s.%s' can't find value '%s'",
object_get_typename(OBJECT(dev)), propname, str);
goto fail;
}
if (blk_attach_dev(blk, dev) < 0) {
DriveInfo *dinfo = blk_legacy_dinfo(blk);
if (dinfo && dinfo->type != IF_NONE) {
error_setg(errp, "Drive '%s' is already in use because "
"it has been automatically connected to another "
"device (did you need 'if=none' in the drive options?)",
str);
} else {
error_setg(errp, "Drive '%s' is already in use by another device",
str);
}
goto fail;
}
*ptr = blk;
fail:
if (blk_created) {
/* If we need to keep a reference, blk_attach_dev() took it */
blk_unref(blk);
}
}
static void release_drive(Object *obj, const char *name, void *opaque)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
BlockBackend **ptr = qdev_get_prop_ptr(dev, prop);
if (*ptr) {
blockdev_auto_del(*ptr);
blk_detach_dev(*ptr, dev);
}
}
static char *print_drive(void *ptr)
{
return g_strdup(blk_name(ptr));
}
static void get_drive(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
get_pointer(obj, v, opaque, print_drive, name, errp);
}
static void set_drive(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
set_pointer(obj, v, opaque, parse_drive, name, errp);
}
PropertyInfo qdev_prop_drive = {
.name = "str",
.description = "Node name or ID of a block device to use as a backend",
.get = get_drive,
.set = set_drive,
.release = release_drive,
};
/* --- character device --- */
static void parse_chr(DeviceState *dev, const char *str, void **ptr,
const char *propname, Error **errp)
{
CharDriverState *chr = qemu_chr_find(str);
if (chr == NULL) {
error_setg(errp, "Property '%s.%s' can't find value '%s'",
object_get_typename(OBJECT(dev)), propname, str);
return;
}
if (qemu_chr_fe_claim(chr) != 0) {
error_setg(errp, "Property '%s.%s' can't take value '%s', it's in use",
object_get_typename(OBJECT(dev)), propname, str);
return;
}
*ptr = chr;
}
static void release_chr(Object *obj, const char *name, void *opaque)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
CharDriverState **ptr = qdev_get_prop_ptr(dev, prop);
CharDriverState *chr = *ptr;
if (chr) {
qemu_chr_add_handlers(chr, NULL, NULL, NULL, NULL);
qemu_chr_fe_release(chr);
}
}
static char *print_chr(void *ptr)
{
CharDriverState *chr = ptr;
const char *val = chr->label ? chr->label : "";
return g_strdup(val);
}
static void get_chr(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
get_pointer(obj, v, opaque, print_chr, name, errp);
}
static void set_chr(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
set_pointer(obj, v, opaque, parse_chr, name, errp);
}
PropertyInfo qdev_prop_chr = {
.name = "str",
.description = "ID of a chardev to use as a backend",
.get = get_chr,
.set = set_chr,
.release = release_chr,
};
/* --- netdev device --- */
static void get_netdev(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
NICPeers *peers_ptr = qdev_get_prop_ptr(dev, prop);
char *p = g_strdup(peers_ptr->ncs[0] ? peers_ptr->ncs[0]->name : "");
visit_type_str(v, name, &p, errp);
g_free(p);
}
static void set_netdev(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
NICPeers *peers_ptr = qdev_get_prop_ptr(dev, prop);
NetClientState **ncs = peers_ptr->ncs;
NetClientState *peers[MAX_QUEUE_NUM];
Error *local_err = NULL;
int queues, err = 0, i = 0;
char *str;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
visit_type_str(v, name, &str, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
queues = qemu_find_net_clients_except(str, peers,
NET_CLIENT_OPTIONS_KIND_NIC,
MAX_QUEUE_NUM);
if (queues == 0) {
err = -ENOENT;
goto out;
}
if (queues > MAX_QUEUE_NUM) {
error_setg(errp, "queues of backend '%s'(%d) exceeds QEMU limitation(%d)",
str, queues, MAX_QUEUE_NUM);
goto out;
}
for (i = 0; i < queues; i++) {
if (peers[i] == NULL) {
err = -ENOENT;
goto out;
}
if (peers[i]->peer) {
err = -EEXIST;
goto out;
}
if (ncs[i]) {
err = -EINVAL;
goto out;
}
ncs[i] = peers[i];
ncs[i]->queue_index = i;
}
peers_ptr->queues = queues;
out:
error_set_from_qdev_prop_error(errp, err, dev, prop, str);
g_free(str);
}
PropertyInfo qdev_prop_netdev = {
.name = "str",
.description = "ID of a netdev to use as a backend",
.get = get_netdev,
.set = set_netdev,
};
/* --- vlan --- */
static int print_vlan(DeviceState *dev, Property *prop, char *dest, size_t len)
{
NetClientState **ptr = qdev_get_prop_ptr(dev, prop);
if (*ptr) {
int id;
if (!net_hub_id_for_client(*ptr, &id)) {
return snprintf(dest, len, "%d", id);
}
}
return snprintf(dest, len, "<null>");
}
static void get_vlan(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
NetClientState **ptr = qdev_get_prop_ptr(dev, prop);
int32_t id = -1;
if (*ptr) {
int hub_id;
if (!net_hub_id_for_client(*ptr, &hub_id)) {
id = hub_id;
}
}
visit_type_int32(v, name, &id, errp);
}
static void set_vlan(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
NICPeers *peers_ptr = qdev_get_prop_ptr(dev, prop);
NetClientState **ptr = &peers_ptr->ncs[0];
Error *local_err = NULL;
int32_t id;
NetClientState *hubport;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
visit_type_int32(v, name, &id, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (id == -1) {
*ptr = NULL;
return;
}
if (*ptr) {
error_set_from_qdev_prop_error(errp, -EINVAL, dev, prop, name);
return;
}
hubport = net_hub_port_find(id);
if (!hubport) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
name, prop->info->name);
return;
}
*ptr = hubport;
}
PropertyInfo qdev_prop_vlan = {
.name = "int32",
.description = "Integer VLAN id to connect to",
.print = print_vlan,
.get = get_vlan,
.set = set_vlan,
};
void qdev_prop_set_drive(DeviceState *dev, const char *name,
BlockBackend *value, Error **errp)
{
const char *ref = "";
if (value) {
ref = blk_name(value);
if (!*ref) {
BlockDriverState *bs = blk_bs(value);
if (bs) {
ref = bdrv_get_node_name(bs);
}
}
}
object_property_set_str(OBJECT(dev), ref, name, errp);
}
void qdev_prop_set_chr(DeviceState *dev, const char *name,
CharDriverState *value)
{
assert(!value || value->label);
object_property_set_str(OBJECT(dev),
value ? value->label : "", name, &error_abort);
}
void qdev_prop_set_netdev(DeviceState *dev, const char *name,
NetClientState *value)
{
assert(!value || value->name);
object_property_set_str(OBJECT(dev),
value ? value->name : "", name, &error_abort);
}
void qdev_set_nic_properties(DeviceState *dev, NICInfo *nd)
{
qdev_prop_set_macaddr(dev, "mac", nd->macaddr.a);
if (nd->netdev) {
qdev_prop_set_netdev(dev, "netdev", nd->netdev);
}
if (nd->nvectors != DEV_NVECTORS_UNSPECIFIED &&
object_property_find(OBJECT(dev), "vectors", NULL)) {
qdev_prop_set_uint32(dev, "vectors", nd->nvectors);
}
nd->instantiated = 1;
}