On 9/24/24 05:08, Daniel P. Berrangé wrote:
On Tue, Sep 24, 2024 at 01:02:26PM +0100, Alex Bennée wrote:
Manos Pitsidianakis <manos.pitsidiana...@linaro.org> writes:
Hello Daniel,
On Tue, 24 Sept 2024 at 11:45, Daniel P. Berrangé <berra...@redhat.com> wrote:
On Mon, Sep 23, 2024 at 10:09:32PM +0300, Manos Pitsidianakis wrote:
Hello Daniel,
On Mon, 23 Sep 2024 19:45, "Daniel P. Berrangé" <berra...@redhat.com> wrote:
On Mon, Sep 23, 2024 at 09:05:24AM +0300, Manos Pitsidianakis wrote:
<snip>
ie, look a query-audiodevs to discover what audio baxckends are
built-in, don't look for CONFIG_XXX settings related to audio.
If there are gaps in information we can query from QMP, we should
aim to close those gaps.
IOW, I don't think we should expose this build info info in either
human readable or machine readable format.
QAPI/QMP is not the perspective of this patch, this is for people who use
custom-built (i.e. not from a distro) binaries and want to be able to
identify how it was built. Launching a binary to query stuff is
unnecessarily complex for this task, and the info is not generally
interesting to the API consumers as you said.
Launching QEMU to talk QMP is our defined public API for querying
anything about the capabilities of QEMU. We're worked hard to get
away from providing ad-hoc ways to query QEMU from the command
line and going back to that is not desirable. It may be slightly
more complicated, but not by very much.
Again, this is not a "capabilities discovery" API. It lists the
build-time configuration of the binary. Perhaps we can expose it in a
different way so that people don't end up confused?
I think the problem is however much we might say it's not a capabilities
discovery API it's very existence encourages users to use it as one.
What about a script:
qemu-get-build-info </path/to/qemu>
which would launch the binary and query it over QMP? Would that work?
If this is purely a debugging aid, we could make use of ELF notes to
just stick the config-host.h content into the binary. This has precedent
in systemd package notes (https://github.com/systemd/package-notes) and
is more clearly *NOT* an end user CLI option, nor a public API in QMP.
Querying is then
objdump -j .note.qemu-config-h -s /usrbin/qemu-system-x86_64
With regards,
Daniel
This is neat!
@Manos: it would be convenient to still have a script as Alex mentioned,
as remembering in which notes the information is hidden might be annoying.
