Commit Graph
48 Commits
Author SHA1 Message Date
Stefan Hajnoczi f96b157ebb Merge tag 'accel-20250715' of https://github.com/philmd/qemu into staging
Accelerators patches

- Unify x86/arm hw/xen/arch_hvm.h header
- Move non-system-specific 'accel/accel-ops.h' and 'accel-cpu-ops.h' to accel/
- Move KVM definitions qapi/accelerator.json
- Add @qom-type field to CpuInfoFast QAPI structure
- Display CPU model name in 'info cpus' HMP command
- Introduce @x-accel-stats QMP command
- Add 'info accel' on HMP
- Improve qemu_add_vm_change_state_handler*() docstring
- Extract TCG statistic related code to tcg-stats.c
- Implement AccelClass::get_[vcpu]_stats() handlers for TCG and HVF
- Do not dump NaN in TCG statistics
- Revert incomplete "accel/tcg: Unregister the RCU before exiting RR thread"

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 # Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* tag 'accel-20250715' of https://github.com/philmd/qemu:
  system/runstate: Document qemu_add_vm_change_state_handler_prio* in hdr
  system/runstate: Document qemu_add_vm_change_state_handler()
  accel/hvf: Implement AccelClass::get_vcpu_stats() handler
  accel/tcg: Implement AccelClass::get_stats() handler
  accel/tcg: Propagate AccelState to dump_accel_info()
  accel/system: Add 'info accel' on human monitor
  accel/system: Introduce @x-accel-stats QMP command
  accel/tcg: Extract statistic related code to tcg-stats.c
  Revert "accel/tcg: Unregister the RCU before exiting RR thread"
  accel: Extract AccelClass definition to 'accel/accel-ops.h'
  accel: Rename 'system/accel-ops.h' -> 'accel/accel-cpu-ops.h'
  accel/tcg: Do not dump NaN statistics
  hw/core/machine: Display CPU model name in 'info cpus' command
  qapi/machine: Add @qom-type field to CpuInfoFast structure
  qapi/accel: Move definitions related to accelerators in their own file
  hw/arm/xen-pvh: Remove unnecessary 'hw/xen/arch_hvm.h' header
  hw/xen/arch_hvm: Unify x86 and ARM variants

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Conflicts:
  qapi/machine.json
  Commit 0462da9d6b ("qapi: remove trivial "Returns:" sections")
  removed trivial "Returns:". This caused a conflict with the move from
  machine.json to accelerator.json.
2025-07-16 07:13:40 -04:00
Philippe Mathieu-Daudé 18da42ee42 qapi/accel: Move definitions related to accelerators in their own file
Extract KVM definitions from machine.json to accelerator.json.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20250703105540.67664-29-philmd@linaro.org>
2025-07-15 19:28:02 +02:00
John SnowandMarkus Armbruster 6c10778826 docs/sphinx: remove special parsing for freeform sections
Remove the QAPI doc section heading syntax, use plain rST section
headings instead.

Tests and documentation are updated to match.

Interestingly, Plain rST headings work fine before this patch, except
for over- and underlining with '=', which the doc parser rejected as
invalid QAPI doc section heading in free-form comments.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250618165353.1980365-5-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Add more detail to commit message]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2025-07-14 10:08:27 +02:00
Daniel P. BerrangéandMarkus Armbruster f8d41d0511 qapi: make s390x specific CPU commands unconditionally available
This removes the TARGET_S390X and CONFIG_KVM conditions from the
CPU commands that are conceptually specific to s390x. Top level
stubs are provided to cope with non-s390x targets, or builds
without KVM.

The removal of CONFIG_KVM is justified by the fact there is no
conceptual difference between running 'qemu-system-s390x -accel tcg'
on a build with and without KVM built-in, so apps only using TCG
can't rely on the CONFIG_KVM in the schema.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-ID: <20250522190542.588267-11-pierrick.bouvier@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2025-05-28 18:56:08 +02:00
Daniel P. BerrangéandMarkus Armbruster 0a1f83c3fb qapi: remove the misc-target.json file
This file is now empty and can thus be removed.

Observe the pre-existing bug with s390-skeys.c and target/i386/monitor.c
both including qapi-commands-misc-target.h despite not requiring it.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-ID: <20250522190542.588267-8-pierrick.bouvier@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2025-05-28 18:54:18 +02:00
Daniel P. BerrangéandMarkus Armbruster 30fbb25871 qapi: expose query-gic-capability command unconditionally
This removes the TARGET_ARM condition from the query-gic-capability
command. This requires providing a QMP command stub for non-ARM targets.
This in turn requires moving the command out of misc-target.json, since
that will trigger symbol poisoning errors when built from target
independent code.

Following the earlier precedent, this creates a misc-arm.json file to
hold this ARM specific command.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-ID: <20250522190542.588267-5-pierrick.bouvier@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2025-05-28 18:54:18 +02:00
Daniel P. BerrangéandMarkus Armbruster a78a91feee qapi: expose rtc-reset-reinjection command unconditionally
This removes the TARGET_I386 condition from the rtc-reset-reinjection
command. This requires providing a QMP command stub for non-i386 target.
This in turn requires moving the command out of misc-target.json, since
that will trigger symbol poisoning errors when built from target
independent code.

Rather than putting the command into misc.json, it is proposed to create
misc-$TARGET.json files to hold commands whose impl is conceptually
only applicable to a single target. This gives an obvious docs hint to
consumers that the command is only useful in relation a specific target,
while misc.json is for commands applicable to 2 or more targets.

The current impl of qmp_rtc_reset_reinject() is a no-op if the i386
RTC is disabled in Kconfig, or if the running machine type lack any
RTC device.

The stub impl for non-i386 targets retains this no-op behaviour.
However, it is now reporting an Error mentioning this command is not
available for current target.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-ID: <20250522190542.588267-2-pierrick.bouvier@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2025-05-28 18:26:23 +02:00
Markus Armbruster 9199d324a8 qapi/qapi-schema: Address the introduction's bit rot
Cut the crap that stopped making sense years ago.  Adjust the
remainder.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20250404121413.1743790-10-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2025-04-08 09:04:34 +02:00
Markus Armbruster d0ae5a3058 qapi/qapi-schema: Update introduction for example notation
The introduction explains example notation.  The series merged in
merge commit e6485190f7 (in 9.1) improved how they look in generated
docs, but neglected to update the introduction accordingly.  Do that
now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20250404121413.1743790-9-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2025-04-08 09:04:34 +02:00
John SnowandMarkus Armbruster 602c90beae docs: add QAPI namespace "QMP" to qemu-qmp-ref
This also creates the qapi-qmp-index.html index and cross-reference
target.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250313044312.189276-10-jsnow@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2025-03-14 07:32:41 +01:00
John SnowandMarkus Armbruster a377f39f38 docs: enable qapidoc transmogrifier for QEMU QMP Reference
We are not enabling the transmogrifier for QSD or QGA yet because we
don't (yet) have a way to create separate indices, and all of the
definitions will bleed together, which isn't so nice.

For now, QMP is better than nothing at all!

Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250311034303.75779-62-jsnow@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2025-03-11 10:26:52 +01:00
Gerd Hoffmann 12058948ab hw/uefi: add var-service-json.c + qapi for NV vars.
Define qapi schema for the uefi variable store state.

Use it and the generated visitor helper functions to store persistent
(EFI_VARIABLE_NON_VOLATILE) variables in JSON format on disk.

Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-ID: <20250225163031.1409078-15-kraxel@redhat.com>
[ incremental fix squashed in ]
Message-ID: <pji24p6oag7cn2rovus7rquo7q2c6tokuquobfro2sqorky7vu@tk7cxud6jw7f>
2025-03-04 12:02:50 +01:00
Avihai HoronandCédric Le Goater a0359b56ec qapi/vfio: Add VFIO migration QAPI event
Add a new QAPI event for VFIO migration. This event will be emitted when
a VFIO device changes its migration state, for example, during migration
or when stopping/starting the guest.

This event can be used by management applications to get updates on the
current state of the VFIO device for their own purposes.

Note that this new event is introduced since VFIO devices have a unique
set of migration states which cannot be described as accurately by other
existing events such as run state or migration status.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
2024-05-16 16:59:19 +02:00
Philippe Mathieu-Daudé 1dfd42c426 hw/rdma: Remove deprecated pvrdma device and rdmacm-mux helper
The whole RDMA subsystem was deprecated in commit e9a54265f5
("hw/rdma: Deprecate the pvrdma device and the rdma subsystem")
released in v8.2.

Remove:
 - PVRDMA device
 - generated vmw_pvrdma/ directory from linux-headers
 - rdmacm-mux tool from contrib/

Cc: Yuval Shaia <yuval.shaia.ml@gmail.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20240328130255.52257-2-philmd@linaro.org>
2024-04-24 16:03:38 +02:00
Andrew MelnychenkoandJason Wang e88899fa90 qmp: Added new command to retrieve eBPF blob.
Now, the binary objects may be retrieved by id.
It would require for future qmp commands that may require specific
eBPF blob.

Added command "request-ebpf". This command returns
eBPF program encoded base64. The program taken from the
skeleton and essentially is an ELF object that can be
loaded in the future with libbpf.

The reason to use the command to provide the eBPF object
instead of a separate artifact was to avoid issues related
to finding the eBPF itself. eBPF object is an ELF binary
that contains the eBPF program and eBPF map description(BTF).
Overall, eBPF object should contain the program and enough
metadata to create/load eBPF with libbpf. As the eBPF
maps/program should correspond to QEMU, the eBPF can't
be used from different QEMU build.

The first solution was a helper that comes with QEMU
and loads appropriate eBPF objects. And the issue is
to find a proper helper if the system has several
different QEMUs installed and/or built from the source,
which helpers may not be compatible.

Another issue is QEMU updating while there is a running
QEMU instance. With an updated helper, it may not be
possible to hotplug virtio-net device to the already
running QEMU. Overall, requesting the eBPF object from
QEMU itself solves possible failures with acceptable effort.

Links:
[PATCH 3/5] qmp: Added the helper stamp check.
https://lore.kernel.org/all/20230219162100.174318-4-andrew@daynix.com/

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-03-12 19:31:47 +08:00
Pierre MorelandThomas Huth 5de1aff255 CPU topology: extend with s390 specifics
S390 adds two new SMP levels, drawers and books to the CPU
topology.
S390 CPUs have specific topology features like dedication and
entitlement. These indicate to the guest information on host
vCPU scheduling and help the guest make better scheduling decisions.

Add the new levels to the relevant QAPI structs.
Add all the supported topology levels, dedication and entitlement
as properties to S390 CPUs.
Create machine-common.json so we can later include it in
machine-target.json also.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Message-ID: <20231016183925.2384704-3-nsg@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-10-20 07:16:53 +02:00
Peter MaydellandMarkus Armbruster d56572584d docs/interop: Convert qmp-spec.txt to rST
Convert the qmp-spec.txt document to restructuredText.
Notable points about the conversion:
 * numbers at the start of section headings are removed, to match
   the style of the rest of the manual
 * cross-references to other sections or documents are hyperlinked
 * various formatting tweaks (notably the examples, which need the
   -> and <- prefixed so the QMP code-block lexer will accept them)
 * English prose fixed in a few places

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20230515162245.3964307-2-peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
[.. code-block:: dumbed down to :: to work around CI failure]
2023-05-22 10:21:01 +02:00
Markus Armbruster a937b6aa73 qapi: Reformat doc comments to conform to current conventions
Change

    # @name: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed
    #        do eiusmod tempor incididunt ut labore et dolore magna aliqua.

to

    # @name: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed
    #     do eiusmod tempor incididunt ut labore et dolore magna aliqua.

See recent commit "qapi: Relax doc string @name: description
indentation rules" for rationale.

Reflow paragraphs to 70 columns width, and consistently use two spaces
to separate sentences.

To check the generated documentation does not change, I compared the
generated HTML before and after this commit with "wdiff -3".  Finds no
differences.  Comparing with diff is not useful, as the reflown
paragraphs are visible there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230428105429.1687850-18-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Acked-by: Lukas Straub <lukasstraub2@web.de>
[Straightforward conflicts in qapi/audio.json qapi/misc-target.json
qapi/run-state.json resolved]
2023-05-10 10:01:01 +02:00
Markus Armbruster 4622c70689 qapi storage-daemon/qapi: Fix documentation section structure
In the QEMU QMP Reference Manual, subsection "Block core (VM
unrelated)" is empty.  Its contents is at the end of subsection
"Background jobs" instead.  That's because qapi/job.json is included
first from qapi/block-core.json, which makes qapi/job.json's
documentation go between qapi/block-core.json's subsection heading and
contents.

In the QEMU Storage Daemon QMP Reference Manual, section "Block
Devices" contains nothing but an empty subsection "Block core (VM
unrelated)".  The latter's contents is at the end section "Socket data
types", along with subsection "Block device exports".  Subsection
"Background jobs" is at the end of section "Cryptography".  All this
is because storage-daemon/qapi/qapi-schema.json includes modules in a
confused order.

Fix both as follows.

Turn subsection "Background jobs" into a section.

Move it before section "Block devices" in the QEMU QMP Reference
Manual, by including qapi/jobs.json right before qapi/block.json.

Reorder include directives in storage-daemon/qapi/qapi-schema.json to
match the order in qapi/qapi-schema.json, so that the QEMU Storage
Daemon QMP Reference Manual's section structure the QEMU QMP Reference
Manual's.

In the QEMU QMP Reference Manual, qapi/cryptodev.json's documentation
is at the end of section "Virtio devices".  That's because it lacks a
section heading, and therefore gets squashed into whatever section
happens to precede it.

Add section heading so it's in section "Cryptography devices".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230425064223.820979-17-armbru@redhat.com>
2023-04-28 11:48:34 +02:00
Markus Armbruster 5042854db8 qapi: Delete largely misleading "Stability Considerations"
Documentation section "Stability Considerations" dates back to the
early days of QMP (commit 82a56f0d83 (Monitor: Introduce the
qmp-commands.hx file)).  It became largely misleading years ago.
Delete it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230425064223.820979-9-armbru@redhat.com>
2023-04-28 11:48:34 +02:00
Jonathan CameronandMichael S. Tsirkin 415442a1b4 hw/mem/cxl_type3: Add CXL RAS Error Injection Support.
CXL uses PCI AER Internal errors to signal to the host that an error has
occurred. The host can then read more detailed status from the CXL RAS
capability.

For uncorrectable errors: support multiple injection in one operation
as this is needed to reliably test multiple header logging support in an
OS. The equivalent feature doesn't exist for correctable errors, so only
one error need be injected at a time.

Note:
 - Header content needs to be manually specified in a fashion that
   matches the specification for what can be in the header for each
   error type.

Injection via QMP:
{ "execute": "qmp_capabilities" }
...
{ "execute": "cxl-inject-uncorrectable-errors",
  "arguments": {
    "path": "/machine/peripheral/cxl-pmem0",
    "errors": [
        {
            "type": "cache-address-parity",
            "header": [ 3, 4]
        },
        {
            "type": "cache-data-parity",
            "header": [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31]
        },
        {
            "type": "internal",
            "header": [ 1, 2, 4]
        }
        ]
  }}
...
{ "execute": "cxl-inject-correctable-error",
    "arguments": {
        "path": "/machine/peripheral/cxl-pmem0",
        "type": "physical"
    } }

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230302133709.30373-9-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-07 12:39:00 -05:00
zhenwei piandMichael S. Tsirkin 14c9fd1673 cryptodev: Introduce cryptodev.json
Introduce QCryptodevBackendType in cryptodev.json, also apply this to
related codes. Then we can drop 'enum CryptoDevBackendOptionsType'.

Note that `CRYPTODEV_BACKEND_TYPE_NONE` is *NOT* used by anywhere, so
drop it(no 'none' enum in QCryptodevBackendType).

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230301105847.253084-2-pizhenwei@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-07 12:38:59 -05:00
Laurent VivierandMichael S. Tsirkin a5ebce3857 qmp: add QMP command x-query-virtio
This new command lists all the instances of VirtIODevices with
their canonical QOM path and name.

[Jonah: @virtio_list duplicates information that already exists in
 the QOM composition tree. However, extracting necessary information
 from this tree seems to be a bit convoluted.

 Instead, we still create our own list of realized virtio devices
 but use @qmp_qom_get with the device's canonical QOM path to confirm
 that the device exists and is realized. If the device exists but
 is actually not realized, then we remove it from our list (for
 synchronicity to the QOM composition tree).

 Also, the QMP command @x-query-virtio is redundant as @qom-list
 and @qom-get are sufficient to search '/machine/' for realized
 virtio devices. However, @x-query-virtio is much more convenient
 in listing realized virtio devices.]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-2-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Mark KandaandPaolo Bonzini b9f88dc071 qmp: Support for querying stats
Gathering statistics is important for development, for monitoring and
for performance measurement.  There are tools such as kvm_stat that do
this and they rely on the _user_ knowing the interesting data points
rather than the tool (which can treat them as opaque).

The commands introduced in this commit introduce QMP support for
querying stats; the goal is to take the capabilities of these tools
and making them available throughout the whole virtualization stack,
so that one can observe, monitor and measure virtual machines without
having shell access + root on the host that runs them.

query-stats returns a list of all stats per target type (only VM
and vCPU to start); future commits add extra options for specifying
stat names, vCPU qom paths, and providers.  All these are used by the
HMP command "info stats".  Because of the development usecases around
statistics, a good HMP interface is important.

query-stats-schemas returns a list of stats included in each target
type, with an option for specifying the provider.  The concepts in the
schema are based on the KVM binary stats' own introspection data, just
translated to QAPI.

There are two reasons to have a separate schema that is not tied to
the QAPI schema.  The first is the contents of the schemas: the new
introspection data provides different information than the QAPI data,
namely unit of measurement, how the numbers are gathered and change
(peak/instant/cumulative/histogram), and histogram bucket sizes.
There's really no reason to have this kind of metadata in the QAPI
introspection schema (except possibly for the unit of measure, but
there's a very weak justification).

Another reason is the dynamicity of the schema.  The QAPI introspection
data is very much static; and while QOM is somewhat more dynamic,
generally we consider that to be a bug rather than a feature these days.
On the other hand, the statistics that are exposed by QEMU might be
passed through from another source, such as KVM, and the disadvantages of
manually updating the QAPI schema for outweight the benefits from vetting
the statistics and filtering out anything that seems "too unstable".
Running old QEMU with new kernel is a supported usecase; if old QEMU
cannot expose statistics from a new kernel, or if a kernel developer
needs to change QEMU before gathering new info from the new kernel,
then that is a poor user interface.

The framework provides a method to register callbacks for these QMP
commands.  Most of the work in fact is done by the callbacks, and a
large majority of this patch is new QAPI structs and commands.

Examples (with KVM stats):

- Query all VM stats:

{ "execute": "query-stats", "arguments" : { "target": "vm" } }

{ "return": [
     { "provider": "kvm",
       "stats": [
          { "name": "max_mmu_page_hash_collisions", "value": 0 },
          { "name": "max_mmu_rmap_size", "value": 0 },
          { "name": "nx_lpage_splits", "value": 148 },
          ... ] },
     { "provider": "xyz",
       "stats": [ ... ] }
] }

- Query all vCPU stats:

{ "execute": "query-stats", "arguments" : { "target": "vcpu" } }

{ "return": [
     { "provider": "kvm",
       "qom_path": "/machine/unattached/device[0]"
       "stats": [
          { "name": "guest_mode", "value": 0 },
          { "name": "directed_yield_successful", "value": 0 },
          { "name": "directed_yield_attempted", "value": 106 },
          ... ] },
     { "provider": "kvm",
       "qom_path": "/machine/unattached/device[1]"
       "stats": [
          { "name": "guest_mode", "value": 0 },
          { "name": "directed_yield_successful", "value": 0 },
          { "name": "directed_yield_attempted", "value": 106 },
          ... ] },
] }

- Retrieve the schemas:

{ "execute": "query-stats-schemas" }

{ "return": [
    { "provider": "kvm",
      "target": "vcpu",
      "stats": [
         { "name": "guest_mode",
           "unit": "none",
           "base": 10,
           "exponent": 0,
           "type": "instant" },
        { "name": "directed_yield_successful",
           "unit": "none",
           "base": 10,
           "exponent": 0,
           "type": "cumulative" },
        ... ]
    },
    { "provider": "kvm",
      "target": "vm",
      "stats": [
        { "name": "max_mmu_page_hash_collisions",
           "unit": "none",
           "base": 10,
           "exponent": 0,
           "type": "peak" },
        ... ]
    },
    { "provider": "xyz",
      "target": "vm",
      "stats": [ ... ]
    }
] }

Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:29 +02:00
Markus Armbruster 6dd75472d5 qemu-options: New -compat to set policy for deprecated interfaces
New option -compat lets you configure what to do when deprecated
interfaces get used.  This is intended for testing users of the
management interfaces.  It is experimental.

-compat deprecated-input=<input-policy> configures what to do when
deprecated input is received.  Input policy can be "accept" (accept
silently), or "reject" (reject the request with an error).

-compat deprecated-output=<out-policy> configures what to do when
deprecated output is sent.  Output policy can be "accept" (pass on
unchanged), or "hide" (filter out the deprecated parts).

Default is "accept".  Policies other than "accept" are implemented
later in this series.

For now, -compat covers only syntactic aspects of QMP, i.e. stuff
tagged with feature 'deprecated'.  We may want to extend it to cover
semantic aspects, CLI, and experimental features.

Note that there is no good way for management application to detect
presence of -compat: it's not visible output of query-qmp-schema or
query-command-line-options.  Tolerable, because it's meant for
testing.  If running with -compat fails, skip the test.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-3-armbru@redhat.com>
2021-03-19 15:43:33 +01:00