When querying block limits, different cache modes (in particular
O_DIRECT or not) can result in different limits. Add an option to
'qemu-img info' that allows the user to specify a cache mode, so that
they can get the block limits for the cache mode they intend to use with
their VM.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20251024123041.51254-5-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add a new --limits option to 'qemu-img info' that displays the block
limits for the image and all of its children, making the information
more accessible for human users than in QMP. This option is not enabled
by default because it can be a lot of output that isn't usually relevant
if you're not specifically trying to diagnose some I/O problem.
This makes the same information automatically also available in HMP
'info block -v'.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20251024123041.51254-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add missing long options and --help output,
reorder options for consistency.
Use -B for --backing-format, keep -F for
backwards compatibility.
Options added:
--format, --cache - for the image in question
--backing, --backing-format, --backing-cache, --backing-unsafe -
for the new backing file
(was eg CACHE vs SRC_CACHE, which is unclear).
Probably should rename local variables.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Message-ID: <20250531171609.197078-19-mjt@tls.msk.ru>
[kwolf: Removed command description from the argument list]
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When no -l/-a/-c/-d specified, assume -l (list).
Use the same values for SNAPSHOT_LIST/etc constants as the
option chars (lacd), this makes it possible to simplify
option handling a lot, combining cases for 4 options into
one.
Also remove bdrv_oflags handling (only list can use RO mode).
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20250531171609.197078-17-mjt@tls.msk.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add missing long options and --help output.
Reorder options for consistency.
Use -b for --backing, and recognize -B for backwards
compatibility. Unfortunately we can't use -B to
specify backing format.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Message-ID: <20250715140702.131321-1-mjt@tls.msk.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Create helper function cmd_help() to display command-specific
help text, and use it to print --help for 'create' subcommand.
Add missing long options (eg --format) in img_create().
Recognize -B option for --backing-format, keep -F for
backward compatibility,
Reorder options for consistency.
Remove usage of missing_argument()/unrecognized_option() in
img_create().
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Message-ID: <20250531171609.197078-6-mjt@tls.msk.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Although defaulting the handshake limit to 10 seconds was a nice QoI
change to weed out intentionally slow clients, it can interfere with
integration testing done with manual NBD_OPT commands over 'nbdsh
--opt-mode'. Expose a command line option to allow the user to alter
the timeout away from the default. This option is unlikely to be used
in enough scenarios to warrant a short option letter.
The option --handshake-limit intentionally differs from the name of
the constant added in commit fb1c2aaa98 (limit instead of max_secs)
and the QMP name to be added in the next commit; this is because
typing a longer command-line name is undesirable and there is
sufficient --help text to document the units.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20250203222722.650694-5-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
It has been deprecated since 8.1; remove it and suggest using the 'local' file
system backend driver instead or virtiofsd.
Acked-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a privileged helper to access RAPL MSR.
The privileged helper tool, qemu-vmsr-helper, is designed to provide
virtual machines with the ability to read specific RAPL (Running Average
Power Limit) MSRs without requiring CAP_SYS_RAWIO privileges or relying
on external, out-of-tree patches.
The helper tool leverages Unix permissions and SO_PEERCRED socket
options to enforce access control, ensuring that only processes
explicitly requesting read access via readmsr() from a valid Thread ID
can access these MSRs.
The list of RAPL MSRs that are allowed to be read by the helper tool is
defined in rapl-msr-index.h. This list corresponds to the RAPL MSRs that
will be supported in the next commit titled "Add support for RAPL MSRs
in KVM/QEMU."
The tool is intentionally designed to run on the Linux x86 platform.
This initial implementation is tailored for Intel CPUs but can be
extended to support AMD CPUs in the future.
Signed-off-by: Anthony Harivel <aharivel@redhat.com>
Link: https://lore.kernel.org/r/20240522153453.1230389-3-aharivel@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If we rebase an image whose backing file has compressed clusters, we
might end up wasting disk space since the copied clusters are now
uncompressed. In order to have better control over this, let's add
"--compress" option to the "qemu-img rebase" command.
Note that this option affects only the clusters which are actually being
copied from the original backing file. The clusters which were
uncompressed in the target image will remain so.
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-8-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
As recent CVE-2023-2861 (fixed by f6b0de53fb) once again showed, the 9p
'proxy' fs driver is in bad shape. Using the 'proxy' backend was already
discouraged for safety reasons before and we recommended to use the
'local' backend (preferably in conjunction with its 'mapped' security
model) instead, but now it is time to officially deprecate the 'proxy'
backend.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <E1qDkmw-0007M1-8f@lizzy.crudebyte.com>
Remove all the virtiofsd build and docs infrastructure.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
