block: Initial implementation of -blockdev

The new command line option -blockdev works like QMP command
blockdev-add.

The option argument may be given in JSON syntax, exactly as in QMP.
Example usage:

    -blockdev '{"node-name": "foo", "driver": "raw", "file": {"driver": "file", "filename": "foo.img"} }'

The JSON argument doesn't exactly blend into the existing option
syntax, so the traditional KEY=VALUE,... syntax is also supported,
using dotted keys to do the nesting:

    -blockdev node-name=foo,driver=raw,file.driver=file,file.filename=foo.img

This does not yet support lists, but that will be addressed shortly.

Note that calling qmp_blockdev_add() (say via qmp_marshal_block_add())
right away would crash.  We need to stash the configuration for later
instead.  This is crudely done, and bypasses QemuOpts, even though
storing configuration is what QemuOpts is for.  Need to revamp option
infrastructure to support QAPI types like BlockdevOptions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488317230-26248-22-git-send-email-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2017-02-28 22:27:07 +01:00
parent 9d1eab4b95
commit 42e5f39378
2 changed files with 46 additions and 0 deletions

View File

@ -550,6 +550,13 @@ Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
using @file{/dev/cdrom} as filename (@pxref{host_drives}).
ETEXI
DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
"-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
" [,cache.direct=on|off][,cache.no-flush=on|off]\n"
" [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
" [,driver specific parameters...]\n"
" configure a block backend\n", QEMU_ARCH_ALL)
DEF("drive", HAS_ARG, QEMU_OPTION_drive,
"-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
" [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"

39
vl.c
View File

@ -95,6 +95,9 @@ int main(int argc, char **argv)
#include "migration/colo.h"
#include "sysemu/kvm.h"
#include "sysemu/hax.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi-visit.h"
#include "qapi/qmp/qjson.h"
#include "qemu/option.h"
#include "qemu/config-file.h"
@ -2976,6 +2979,13 @@ int main(int argc, char **argv, char **envp)
Error *main_loop_err = NULL;
Error *err = NULL;
bool list_data_dirs = false;
typedef struct BlockdevOptions_queue {
BlockdevOptions *bdo;
Location loc;
QSIMPLEQ_ENTRY(BlockdevOptions_queue) entry;
} BlockdevOptions_queue;
QSIMPLEQ_HEAD(, BlockdevOptions_queue) bdo_queue
= QSIMPLEQ_HEAD_INITIALIZER(bdo_queue);
module_call_init(MODULE_INIT_TRACE);
@ -3118,6 +3128,25 @@ int main(int argc, char **argv, char **envp)
drive_add(IF_DEFAULT, popt->index - QEMU_OPTION_hda, optarg,
HD_OPTS);
break;
case QEMU_OPTION_blockdev:
{
Visitor *v;
BlockdevOptions_queue *bdo;
v = qobject_input_visitor_new_str(optarg, "driver", &err);
if (!v) {
error_report_err(err);
exit(1);
}
bdo = g_new(BlockdevOptions_queue, 1);
visit_type_BlockdevOptions(v, NULL, &bdo->bdo,
&error_fatal);
visit_free(v);
loc_save(&bdo->loc);
QSIMPLEQ_INSERT_TAIL(&bdo_queue, bdo, entry);
break;
}
case QEMU_OPTION_drive:
if (drive_def(optarg) == NULL) {
exit(1);
@ -4451,6 +4480,16 @@ int main(int argc, char **argv, char **envp)
}
/* open the virtual block devices */
while (!QSIMPLEQ_EMPTY(&bdo_queue)) {
BlockdevOptions_queue *bdo = QSIMPLEQ_FIRST(&bdo_queue);
QSIMPLEQ_REMOVE_HEAD(&bdo_queue, entry);
loc_push_restore(&bdo->loc);
qmp_blockdev_add(bdo->bdo, &error_fatal);
loc_pop(&bdo->loc);
qapi_free_BlockdevOptions(bdo->bdo);
g_free(bdo);
}
if (snapshot || replay_mode != REPLAY_MODE_NONE) {
qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot,
NULL, NULL);