There are many existing qcow2 images that specify a backing file but
no format. This has been the source of CVEs in the past, but has
become more prominent of a problem now that libvirt has switched to
-blockdev. With older -drive, at least the probing was always done by
qemu (so the only risk of a changed format between successive boots of
a guest was if qemu was upgraded and probed differently). But with
newer -blockdev, libvirt must specify a format; if libvirt guesses raw
where the image was formatted, this results in data corruption visible
to the guest; conversely, if libvirt guesses qcow2 where qemu was
using raw, this can result in potential security holes, so modern
libvirt instead refuses to use images without explicit backing format.
The change in libvirt to reject images without explicit backing format
has pointed out that a number of tools have been far too reliant on
probing in the past. It's time to set a better example in our own
iotests of properly setting this parameter.
iotest calls to create, rebase, and convert are all impacted to some
degree. It's a bit annoying that we are inconsistent on command line
- while all of those accept -o backing_file=...,backing_fmt=..., the
shortcuts are different: create and rebase have -b and -F, while
convert has -B but no -F. (amend has no shortcuts, but the previous
patch just deprecated the use of amend to change backing chains).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-9-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
One of the recent commits changed the way qemu-io prints out its
errors and warnings - they are now prefixed with the program name.
We've got to adapt the iotests accordingly to prevent that they
are failing.
Fixes: 99e98d7c9f ("qemu-io: Use error_[gs]et_progname()")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This function takes four options (cache.direct, cache.no-flush,
read-only and auto-read-only) from a QemuOpts object and updates the
flags accordingly.
If any of those options is not set (because it was missing from the
original QDict or because it had an invalid value) then the function
aborts with a failed assertion:
$ qemu-io -c 'reopen -o read-only=foo' hd.qcow2
block.c:1126: update_flags_from_options: Assertion `qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT)' failed.
Aborted
This assertion is unnecessary, and it forces any caller of
bdrv_reopen() to pass all the aforementioned four options. This may
have made sense in order to remove ambiguity when bdrv_reopen() was
taking both flags and options, but that's not the case anymore.
It's also unnecessary if we want to validate the option values,
because bdrv_reopen_prepare() already takes care of that, as we can
see if we remove the assertions:
$ qemu-io -c 'reopen -o read-only=foo' hd.qcow2
Parameter 'read-only' expects 'on' or 'off'
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When reopen_f() puts a block device in the reopen queue, some of the
new options are passed using a QDict, but others ("read-only" and the
cache options) are passed as flags.
This patch puts those flags in the QDict. This way the flags parameter
becomes redundant and we'll be able to get rid of it in a subsequent
patch.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20171114180128.17076-6-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
'node-name' and 'driver' should not be changed during a reopen
operation. It is, however, valid to specify them with the same value as
they already had.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Eric Blake
Thomas Huth
Alberto Garcia
Max Reitz
Kevin Wolf