qemu-e2k/hw/core/qdev-properties-system.c
Markus Armbruster 668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00

468 lines
12 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 "audio/audio.h"
#include "net/net.h"
#include "hw/qdev-properties.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 "chardev/char-fe.h"
#include "sysemu/iothread.h"
#include "sysemu/tpm_backend.h"
static bool check_prop_still_unset(DeviceState *dev, const char *name,
const void *old_val, const char *new_val,
Error **errp)
{
const GlobalProperty *prop = qdev_find_global_prop(dev, name);
if (!old_val) {
return true;
}
if (prop) {
error_setg(errp, "-global %s.%s=... conflicts with %s=%s",
prop->driver, prop->property, name, new_val);
} else {
/* Error message is vague, but a better one would be hard */
error_setg(errp, "%s=%s conflicts, and override is not implemented",
name, new_val);
}
return false;
}
/* --- drive --- */
static void get_drive(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
void **ptr = qdev_get_prop_ptr(dev, prop);
const char *value;
char *p;
if (*ptr) {
value = blk_name(*ptr);
if (!*value) {
BlockDriverState *bs = blk_bs(*ptr);
if (bs) {
value = bdrv_get_node_name(bs);
}
}
} else {
value = "";
}
p = g_strdup(value);
visit_type_str(v, name, &p, errp);
g_free(p);
}
static void set_drive_helper(Object *obj, Visitor *v, const char *name,
void *opaque, bool iothread, Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
void **ptr = qdev_get_prop_ptr(dev, prop);
char *str;
BlockBackend *blk;
bool blk_created = false;
int ret;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
if (!visit_type_str(v, name, &str, errp)) {
return;
}
/*
* TODO Should this really be an error? If no, the old value
* needs to be released before we store the new one.
*/
if (!check_prop_still_unset(dev, name, *ptr, str, errp)) {
return;
}
if (!*str) {
g_free(str);
*ptr = NULL;
return;
}
blk = blk_by_name(str);
if (!blk) {
BlockDriverState *bs = bdrv_lookup_bs(NULL, str, NULL);
if (bs) {
/*
* If the device supports iothreads, it will make sure to move the
* block node to the right AioContext if necessary (or fail if this
* isn't possible because of other users). Devices that are not
* aware of iothreads require their BlockBackends to be in the main
* AioContext.
*/
AioContext *ctx = iothread ? bdrv_get_aio_context(bs) :
qemu_get_aio_context();
blk = blk_new(ctx, 0, BLK_PERM_ALL);
blk_created = true;
ret = blk_insert_bs(blk, bs, errp);
if (ret < 0) {
goto fail;
}
}
}
if (!blk) {
error_setg(errp, "Property '%s.%s' can't find value '%s'",
object_get_typename(OBJECT(dev)), prop->name, 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);
}
g_free(str);
}
static void set_drive(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
set_drive_helper(obj, v, name, opaque, false, errp);
}
static void set_drive_iothread(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
set_drive_helper(obj, v, name, opaque, true, errp);
}
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) {
AioContext *ctx = blk_get_aio_context(*ptr);
aio_context_acquire(ctx);
blockdev_auto_del(*ptr);
blk_detach_dev(*ptr, dev);
aio_context_release(ctx);
}
}
const 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,
};
const PropertyInfo qdev_prop_drive_iothread = {
.name = "str",
.description = "Node name or ID of a block device to use as a backend",
.get = get_drive,
.set = set_drive_iothread,
.release = release_drive,
};
/* --- character device --- */
static void get_chr(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
DeviceState *dev = DEVICE(obj);
CharBackend *be = qdev_get_prop_ptr(dev, opaque);
char *p;
p = g_strdup(be->chr && be->chr->label ? be->chr->label : "");
visit_type_str(v, name, &p, errp);
g_free(p);
}
static void set_chr(Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
CharBackend *be = qdev_get_prop_ptr(dev, prop);
Chardev *s;
char *str;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
if (!visit_type_str(v, name, &str, errp)) {
return;
}
/*
* TODO Should this really be an error? If no, the old value
* needs to be released before we store the new one.
*/
if (!check_prop_still_unset(dev, name, be->chr, str, errp)) {
return;
}
if (!*str) {
g_free(str);
be->chr = NULL;
return;
}
s = qemu_chr_find(str);
if (s == NULL) {
error_setg(errp, "Property '%s.%s' can't find value '%s'",
object_get_typename(obj), prop->name, str);
} else if (!qemu_chr_fe_init(be, s, errp)) {
error_prepend(errp, "Property '%s.%s' can't take value '%s': ",
object_get_typename(obj), prop->name, str);
}
g_free(str);
}
static void release_chr(Object *obj, const char *name, void *opaque)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
CharBackend *be = qdev_get_prop_ptr(dev, prop);
qemu_chr_fe_deinit(be, false);
}
const 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];
int queues, err = 0, i = 0;
char *str;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
if (!visit_type_str(v, name, &str, errp)) {
return;
}
queues = qemu_find_net_clients_except(str, peers,
NET_CLIENT_DRIVER_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]->peer) {
err = -EEXIST;
goto out;
}
/*
* TODO Should this really be an error? If no, the old value
* needs to be released before we store the new one.
*/
if (!check_prop_still_unset(dev, name, ncs[i], str, errp)) {
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);
}
const PropertyInfo qdev_prop_netdev = {
.name = "str",
.description = "ID of a netdev to use as a backend",
.get = get_netdev,
.set = set_netdev,
};
/* --- audiodev --- */
static void get_audiodev(Object *obj, Visitor *v, const char* name,
void *opaque, Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
QEMUSoundCard *card = qdev_get_prop_ptr(dev, prop);
char *p = g_strdup(audio_get_id(card));
visit_type_str(v, name, &p, errp);
g_free(p);
}
static void set_audiodev(Object *obj, Visitor *v, const char* name,
void *opaque, Error **errp)
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
QEMUSoundCard *card = qdev_get_prop_ptr(dev, prop);
AudioState *state;
int err = 0;
char *str;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
if (!visit_type_str(v, name, &str, errp)) {
return;
}
state = audio_state_by_name(str);
if (!state) {
err = -ENOENT;
goto out;
}
card->state = state;
out:
error_set_from_qdev_prop_error(errp, err, dev, prop, str);
g_free(str);
}
const PropertyInfo qdev_prop_audiodev = {
.name = "str",
.description = "ID of an audiodev to use as a backend",
/* release done on shutdown */
.get = get_audiodev,
.set = set_audiodev,
};
bool qdev_prop_set_drive_err(DeviceState *dev, const char *name,
BlockBackend *value, Error **errp)
{
const char *ref = "";
if (value) {
ref = blk_name(value);
if (!*ref) {
const BlockDriverState *bs = blk_bs(value);
if (bs) {
ref = bdrv_get_node_name(bs);
}
}
}
return object_property_set_str(OBJECT(dev), name, ref, errp);
}
void qdev_prop_set_drive(DeviceState *dev, const char *name,
BlockBackend *value)
{
qdev_prop_set_drive_err(dev, name, value, &error_abort);
}
void qdev_prop_set_chr(DeviceState *dev, const char *name,
Chardev *value)
{
assert(!value || value->label);
object_property_set_str(OBJECT(dev), name, value ? value->label : "",
&error_abort);
}
void qdev_prop_set_netdev(DeviceState *dev, const char *name,
NetClientState *value)
{
assert(!value || value->name);
object_property_set_str(OBJECT(dev), name, value ? value->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;
}