Commit Graph

151 Commits

Author SHA1 Message Date
Kevin Wolf c2ad1b0c46 block: Allow omitting the file name when using driver-specific options
After this patch, using -drive with an empty file name continues to open
the file if driver-specific options are used. If no driver-specific
options are specified, the semantics stay as it was: It defines a drive
without an inserted medium.

In order to achieve this, bdrv_open() must be made safe to work with a
NULL filename parameter. The assumption that is made is that only block
drivers which implement bdrv_parse_filename() support using driver
specific options and could therefore work without a filename. These
drivers must make sure to cope with NULL in their implementation of
.bdrv_open() (this is only NBD for now). For all other drivers, the
block layer code will make sure to error out before calling into their
code - they can't possibly work without a filename.

Now an NBD connection can be opened like this:

  qemu-system-x86_64 -drive file.driver=nbd,file.port=1234,file.host=::1

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22 17:51:32 +01:00
Peter Lieven 92b7a08d64 block: complete all IOs before resizing a device
this patch ensures that all pending IOs are completed
before a device is resized. this is especially important
if a device is shrinked as it the bdrv_check_request()
result is invalidated.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-22 17:51:31 +01:00
Markus Armbruster 3618a09402 blockdev: Fix up copyright and permission notice
Screwed up in commit 666daa68.  Thanks to Kevin Wolf for reminding me
to fix this.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:51 +01:00
Kevin Wolf 0006383e15 block: Support driver specific options in drive_init()
Any non-default -drive options are now passed down to the block drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Kevin Wolf bb44619b06 blockdev: Keep a copy of DriveInfo.serial
Pointing to a QemuOpts element is surprising and can lead to subtle
use-after-free errors when the QemuOpts is freed after all options are
parsed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Kevin Wolf de9c0cec6c block: Add options QDict to bdrv_open() prototype
It doesn't do anything yet except storing the options QDict in the
BlockDriverState.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Paolo Bonzini a9384aff53 blockdev: add discard suboption to -drive
Add support for BDRV_O_UNMAP from the QEMU command-line.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-02-22 21:29:42 +01:00
Miroslav Rezanina f382d43a91 qemu-img: Add "Quiet mode" option
There can be a need to turn output to stdout off. This patch adds a -q option
that enable "Quiet mode". In Quiet mode, only errors are printed out.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:09 +01:00
Stefan Hajnoczi 7d81c1413c block: refuse negative iops and bps values
Negative I/O throttling iops and bps values do not make sense so reject
them with an error message.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:09 +01:00
Stefan Hajnoczi c546194f26 block: use Error in do_check_io_limits()
The do_check_io_limits() function returns false when I/O limits are
invalid but it doesn't set an Error to indicate why.  The two
do_check_io_limits() callers duplicate error reporting.  Solve this by
passing an Error pointer into do_check_io_limits().

Note that the two callers report slightly different errors: drive_init()
prints a custom error message while qmp_block_set_io_throttle() does
error_set(errp, QERR_INVALID_PARAMETER_COMBINATION).

QERR_INVALID_PARAMETER_COMBINATION is a generic error, see
include/qapi/qmp/qerror.h:

  #define QERR_INVALID_PARAMETER_COMBINATION \
    ERROR_CLASS_GENERIC_ERROR, "Invalid parameter combination"

Since it is generic we are not obliged to keep this error.  Switch to
the custom error message which contains more information.

This patch prepares for adding additional checks with their own error
messages to do_check_io_limits().  The next patch adds a new check.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:09 +01:00
Anthony Liguori 503cb22e05 Merge remote-tracking branch 'kwolf/for-anthony' into staging
# By Paolo Bonzini (14) and others
# Via Kevin Wolf
* kwolf/for-anthony: (24 commits)
  ide: Add fall through annotations
  block: Create proper size file for disk mirror
  ahci: Add migration support
  ahci: Change data types in preparation for migration
  ahci: Remove unused AHCIDevice fields
  hbitmap: add assertion on hbitmap_iter_init
  mirror: do nothing on zero-sized disk
  block/vdi: Check for bad signature
  block/vdi: Improved return values from vdi_open
  block/vdi: Improve debug output for signature
  block: Use error code EMEDIUMTYPE for wrong format in some block drivers
  block: Add special error code for wrong format
  mirror: support arbitrarily-sized iterations
  mirror: support more than one in-flight AIO operation
  mirror: add buf-size argument to drive-mirror
  mirror: switch mirror_iteration to AIO
  mirror: allow customizing the granularity
  block: allow customizing the granularity of the dirty bitmap
  block: return count of dirty sectors, not chunks
  mirror: perform COW if the cluster size is bigger than the granularity
  ...
2013-01-28 14:46:45 -06:00
Vishvananda Ishaya 8689907266 block: Create proper size file for disk mirror
The qmp monitor command to mirror a disk was passing -1 for size
along with the disk's backing file. This size of the resulting disk
is the size of the backing file, which is incorrect if the disk
has been resized. Therefore we should always pass in the size of
the current disk.

Signed-off-by: Vishvananda Ishaya <vishvananda@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:36 +01:00
Stefan Weil 02582abd48 block: Add special error code for wrong format
The block drivers need a special error code for "wrong format".
From the available error codes EMEDIUMTYPE fits best.
It is not available on all platforms, so a definition in
qemu-common.h and a specific error report are needed.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:35 +01:00
Paolo Bonzini 08e4ed6cde mirror: add buf-size argument to drive-mirror
This makes sense when the next commit starts using the extra buffer space
to perform many I/O operations asynchronously.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:34 +01:00
Paolo Bonzini eee13dfe30 mirror: allow customizing the granularity
The desired granularity may be very different depending on the kind of
operation (e.g. continuous replication vs. collapse-to-raw) and whether
the VM is expected to perform lots of I/O while mirroring is in progress.

Allow the user to customize it, while providing a sane default so that
in general there will be no extra allocated space in the target compared
to the source.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:34 +01:00
Paolo Bonzini b812f6719c mirror: perform COW if the cluster size is bigger than the granularity
When mirroring runs, the backing files for the target may not yet be
ready.  However, this means that a copy-on-write operation on the target
would fill the missing sectors with zeros.  Copy-on-write only happens
if the granularity of the dirty bitmap is smaller than the cluster size
(and only for clusters that are allocated in the source after the job
has started copying).  So far, the granularity was fixed to 1MB; to avoid
the problem we detected the situation and required the backing files to
be available in that case only.

However, we want to lower the granularity for efficiency, so we need
a better solution.  The solution is to always copy a whole cluster the
first time it is touched.  The code keeps a bitmap of clusters that
have already been allocated by the mirroring job, and only does "manual"
copy-on-write if the chunk being copied is zero in the bitmap.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:33 +01:00
Jeff Cody 58513bde83 block: Monitor command commit neglects to report some errors
The non-live bdrv_commit() function may return one of the following
errors: -ENOTSUP, -EBUSY, -EACCES, -EIO.  The only error that is
checked in the HMP handler is -EBUSY, so the monitor command 'commit'
silently fails for all error cases other than 'Device is in use'.

Report error using monitor_printf() and strerror(), and convert existing
qerror_report() calls in do_commit() to monitor_printf().

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-01-25 10:36:26 -02:00
Paolo Bonzini 4d4545743f qemu-option: move standard option definitions out of qemu-config.c
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-12 17:17:53 +01:00
Paolo Bonzini 9c17d615a6 softmmu: move include files to include/sysemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:45 +01:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini 83c9089e73 monitor: move include files to include/monitor/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:32 +01:00
Paolo Bonzini 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Paolo Bonzini 7b1b5d1913 qapi: move include files to include/qobject/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Dong Xu Wang e478b448d7 use qemu_opts_create_nofail
We will use qemu_opts_create_nofail function, it can make code
more readable.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 16:35:47 +01:00
Luiz Capitulino cf8f2426c5 qmp: qmp_drive_mirror(): pass Error object to bdrv_img_create()
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:05:10 +01:00
Luiz Capitulino 43e1704115 qmp: qmp_transaction(): pass Error object to bdrv_img_create()
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:05:10 +01:00
Luiz Capitulino 71c79813d8 block: bdrv_img_create(): add Error ** argument
This commit adds an Error ** argument to bdrv_img_create() and set it
appropriately on error.

Callers of bdrv_img_create() pass NULL for the new argument and still
rely on bdrv_img_create()'s return value. Next commits will change
callers to use the Error object instead.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:05:10 +01:00
Christian Borntraeger 2d0d2837dc Support default block interfaces per QEMUMachine
There are QEMUMachines that have neither IF_IDE nor IF_SCSI as a
default/standard interface to their block devices / drives. Therefore,
this patch introduces a new field default_block_type per QEMUMachine
struct. The prior use_scsi field becomes thereby obsolete and is
replaced through .default_block_type = IF_SCSI.

This patch also changes the default for s390x to IF_VIRTIO and
removes an early hack that converts IF_IDE drives.
Other parties have already claimed interest (e.g. IF_SD for exynos)

To create a sane default, for machines that dont specify a
default_block_type, this patch makes IF_IDE = 0 and IF_NONE = 1.
I checked all users of IF_NONE (blockdev.c and ww/device-hotplug.c)
as well as IF_IDE and it seems that it is ok to change the defines -
in other words, I found no obvious (to me) assumption in the code
regarding IF_NONE==0. IF_NONE is only set if there is an
explicit if=none. Without if=* the interface becomes IF_DEFAULT.

I would suggest to have some additional care, e.g. by letting
this patch sit some days in the block tree.

Based on an initial patch from Einar Lueck <elelueck@de.ibm.com>

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Igor Mitsyanko <i.mitsyanko@samsung.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Acked-by: Igor Mitsyanko <i.mitsyanko@samsung.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-12-11 11:05:10 +01:00
Jan Kiszka 0d92d17a6d Issue warning when deprecated drive parameter boot=on|off is used
Releases of qemu-kvm will be interrupted at qemu 1.3.0.
Users should switch to plain qemu releases.
To avoid breaking scenarios which are setup with command line
options specific to qemu-kvm, port these switches from qemu-kvm
to qemu.git.

Port drive boot option. From the qemu-kvm original commit message:

We do not want to maintain this option forever. It will be removed after
a grace period of a few releases. So warn the user that this option has
no effect and will become invalid soon.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-30 23:39:52 -02:00
Paolo Bonzini b952b5589a mirror: add support for on-source-error/on-target-error
Error management is important for mirroring; otherwise, an error on the
target (even something as "innocent" as ENOSPC) requires to start again
with a full copy.  Similar to on_read_error/on_write_error, two separate
knobs are provided for on_source_error (reads) and on_target_error (writes).
The default is 'report' for both.

The 'ignore' policy will leave the sector dirty, so that it will be
retried later.  Thus, it will not cause corruption.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:22 +02:00
Paolo Bonzini d9b902db3f qmp: add drive-mirror command
This adds the monitor commands that start the mirroring job.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:20 +02:00
Paolo Bonzini a66a2a3683 block: introduce BLOCK_JOB_READY event
Even for jobs that need to be manually completed, management may want
to take care itself of the completion, not requiring the user to issue
a command to terminate the job.  In this case we want to avoid that
they poll us continuously, waiting for completion to become available.
Thus, add a new event that signals the phase switch and the availability
of the block-job-complete command.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Paolo Bonzini aeae883baf block: add block-job-complete
While streaming can be dropped as soon as it progressed through the whole
image, mirroring needs to be completed manually for two reasons: 1) so that
management knows exactly when the VM switches to the target; 2) because
for other use cases such as replication, we may leave the operation running
for the whole life of the virtual machine.

Add a new block job command that manually completes background operations.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Jeff Cody d5208c45be block: in commit, determine base image from the top image
This simplifies some code and error checking, and also fixes a bug.

bdrv_find_backing_image() should only be passed absolute filenames,
or filenames relative to the chain.  In the QMP message handler for
block commit, when looking up the base do so from the determined top
image, so we know it is reachable from top.

Some of the error messages put out by block-commit have changed
slightly, which causes 2 tests cases for block-commit to fail.
This patch updates the test cases to look for the correct error
output.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Amos Kong 4d5b97da35 cleanup useless return sentence
This patch cleans up return sentences in the end of void functions.

Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
2012-10-05 15:10:21 +02:00
Paolo Bonzini 1d809098aa stream: add on-error argument
This patch adds support for error management to streaming.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:56 +02:00
Paolo Bonzini 1ceee0d5cc iostatus: change is_read to a bool
Do this while we are touching this part of the code, before introducing
more uses of "int is_read".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:56 +02:00
Paolo Bonzini 92aa5c6d77 iostatus: move BlockdevOnError declaration to QAPI
This will let block-stream reuse the enum.  Places that used the enums
are renamed accordingly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:26 +02:00
Paolo Bonzini 6e37fb811a qmp: add block-job-pause and block-job-resume
Add QMP commands matching the functionality.

Paused jobs cannot be canceled without first resuming them.  This
ensures that I/O errors are never missed by management.  However, an
optional force argument can be specified to allow that.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:14:32 +02:00
Paolo Bonzini 8acc72a4d2 block: add support for job pause/resume
Job pausing reuses the existing support for cancellable sleeps.  A pause
happens at the next sleeping point and lasts until the coroutine is
re-entered explicitly.  Cancellation was already doing a forced resume,
so implement it explicitly in terms of resume.

Paused jobs cannot be canceled without first resuming them.  This ensures
that I/O errors are never missed by management.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:14:32 +02:00
Paolo Bonzini 30e628b709 block: add block_job_query
Extract it out of the implementation of info block-jobs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:14:32 +02:00
Paolo Bonzini 2f0c9fe64c block: move job APIs to separate files
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:14:26 +02:00
Paolo Bonzini 7ef1507045 qerror/block: introduce QERR_BLOCK_JOB_NOT_ACTIVE
The DeviceNotActive text is not a particularly good match, add
a separate text while keeping the same class.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:08:17 +02:00
Jeff Cody ed61fc10e8 QAPI: add command for live block commit, 'block-commit'
The command for live block commit is added, which has the following
arguments:

device: the block device to perform the commit on (mandatory)
base:   the base image to commit into; optional (if not specified,
        it is the underlying original image)
top:    the top image of the commit - all data from inside top down
        to base will be committed into base (mandatory for now; see
        note, below)

speed:  maximum speed, in bytes/sec

Note: Eventually this command will support merging down the active layer,
      but that code is not yet complete.  If the active layer is passed
      in as top, then an error will be returned.  Once merging down the
      active layer is supported, the 'top' argument may become optional,
      and default to the active layer.

The is done as a block job, so upon completion a BLOCK_JOB_COMPLETED will
be emitted.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 18:23:47 +02:00
Jeff Cody 9abf2dbaf6 blockdev: rename block_stream_cb to a generic block_job_cb
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 18:23:16 +02:00
Jeff Cody 870f5681c9 block: after creating a live snapshot, make old image read-only
Currently, after a live snapshot of a drive, the image that has
been 'demoted' to be below the new active layer remains r/w.
This patch reopens it read-only.

Note that we do not check for error on the reopen(), because we
will not abort the snapshots if the reopen fails.

This patch depends on the bdrv_reopen() series.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 17:51:47 +02:00
Kevin Shanahan 80dd1aae36 blockdev: preserve readonly and snapshot states across media changes
If readonly=on is given at device creation time, the ->readonly flag
needs to be set in the block driver state for this device so that
readonly-ness is preserved across media changes (qmp change command).
Similarly, to preserve the snapshot property requires ->open_flags to
be correct.

Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:11 +02:00
Paolo Bonzini 1f212b9d3e blockdev: flip default cache mode from writethrough to writeback
Now all major device models (IDE, SCSI, virtio) can choose between
writethrough and writeback at run-time, and virtio will even revert
to writethrough if the guest is not capable of sending flushes.  So
we can change the default to writeback at last.

Tested, for lack of a better idea, with a breakpoint on bdrv_open
and all cache choices one by one.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-10 10:25:12 +02:00
Peter Maydell c8057f951d Support 'help' as a synonym for '?' in command line options
For command line options which permit '?' meaning 'please list the
permitted values', add support for 'help' as a synonym, by abstracting
the check out into a helper function.

This change means that in some cases where we were being lazy in
our string parsing, "?junk" will now be rejected as an invalid option
rather than being (undocumentedly) treated the same way as "?".

Update the documentation to use 'help' rather than '?', since '?'
is a shell metacharacter and thus prone to fail confusingly if there
is a single character filename in the current working directory and
the '?' has not been escaped. It's therefore better to steer users
towards 'help', though '?' is retained for backwards compatibility.

We do not, however, update the output of the system emulator's -help
(or any documentation autogenerated from the qemu-options.hx which
is the source of the -help text) because libvirt parses our -help
output and will break. At a later date when QEMU provides a better
interface so libvirt can avoid having to do this, we can update the
-help text too.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-08-02 13:16:42 -05:00
Markus Armbruster 577d0a3807 blockdev: Don't limit DriveInfo serial to 20 characters
All current users (IDE, SCSI and virtio-blk) happen to share this 20
characters limit.  Still, it should be left to device models.  They
already enforce their limits.  They have to, as the DriveInfo limit
only affects legacy -drive serial=..., not the qdev properties.

usb-storage, which doesn't limit serial number length, also uses
DriveInfo for -usbdevice.  But that doesn't provide access to
DriveInfo serial.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-17 16:48:32 +02:00