* Peter Maydell (peter.mayd...@linaro.org) wrote: > On Tue, 11 Jun 2024 at 06:50, Markus Armbruster <arm...@redhat.com> wrote: > > > > Philippe Mathieu-Daudé <phi...@linaro.org> writes: > > > > > Officialise the QMP command, use the existing > > > hmp_info_human_readable_text() helper. > > > > I'm not sure "officialise" is a word :) > > > > Taking a step back... "info via" and its new QMP counterpart > > x-query-mos6522-devices dump device state. I understand why examining > > device state via monitor can be useful for debugging. However, we have > > more than 2000 devices in the tree. Clearly, we don't want 2000 device > > state queries. Not even 100. Could we have more generic means instead? > > > > We could use QOM (read-only) properties to expose device state. > > > > If we use one QOM property per "thing", examining device state becomes > > quite tedious. Also, you'd have to stop the guest to get a consistent > > view, and adding lots of QOM properties bloats the code. > > > > If we use a single, object-valued property for the entire state, we get > > to define the objects in QAPI. Differently tedious, and bloats the > > generated code. > > We already have a machine readable mandatory-for-every-device > representation of its entire state -- it's the vmstate struct. > Admittedly this is sometimes a bit different from the guest-facing > view of a device and we don't machine-record the field names...
vmstate might not contain everything needed for debug; devices do a lot of fiddling to create a consistent vmstate, and there may be more that someone debugging wants (e.g. fd's or host memory addresses). It's also hopelessly cryptic. From an HMP point, a 'info debug <DEVICENAME>' seems good to me, possibly with some options as to whether to recurse or perhaps add flags to 'info qtree' to also call it. Dave > -- PMM -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/
