I apologize for taking so long to reply. Khushit Shah <[email protected]> writes:
>> On 19 Jun 2026, at 2:55 PM, Markus Armbruster <[email protected]> wrote: >> >> !-------------------------------------------------------------------| >> CAUTION: External Email >> >> |-------------------------------------------------------------------! >> >> Khushit Shah <[email protected]> writes: >> >>> Introduce 'query-arm-cpu-props-info' QMP command. This command returns >>> information about ARM CPU model properties, including their name, type, >>> supported values on the given host, and composite parent if any. >>> >>> This provides management layer necessary information to determine >>> migration compatibility off a VM on different host. > > Note: s/off/of. > >>> >>> Signed-off-by: Khushit Shah <[email protected]> >>> --- >>> qapi/misc-arm.json | 41 ++++++++++++++++ >>> stubs/qmp-arm-gic.c | 6 +++ >>> target/arm/arm-cpu-props-stub.c | 13 +++++ >>> target/arm/arm-cpu-props.c | 85 +++++++++++++++++++++++++++++++++ >>> target/arm/arm-cpu-props.h | 5 ++ >>> target/arm/arm-qmp-cmds.c | 44 +++++++++++++++++ >>> target/arm/cpu-idregs.c | 71 +++++++++++++++++++++++++++ >>> target/arm/cpu-idregs.h | 8 ++++ >>> 8 files changed, 273 insertions(+) >>> >>> diff --git a/qapi/misc-arm.json b/qapi/misc-arm.json >>> index 4dc66d00e5..1a3fb140c4 100644 >>> --- a/qapi/misc-arm.json >>> +++ b/qapi/misc-arm.json >>> @@ -46,6 +46,47 @@ >>> ## >>> { 'command': 'query-gic-capabilities', 'returns': ['GICCapability'] } >>> >>> +## >>> +# @CpuPropInfo: >> >> CpuPropertyInfo for consistency with type names such as ObjectPropertyInfo. > > Acked. > >>> +# >>> +# Information about a specific ARM CPU model property. >>> +# >>> +# @name: the name of the property >>> +# >>> +# @type: the type of the property, any of ('string', 'boolean', >>> +# 'number'). >>> +# >>> +# @supported-values: the set of values the host hardware supports >>> +# for the property, a list of strings. >> >> I figure the set of values depends on the host, i.e. it isn't known at >> compile time. Correct? >> > > Yes, correct. > >> Are the possible property names known at compile time? > > Yes, property names are known at compile time. Why can't we use a struct then? { 'struct': ... 'data': { 'PROP1': 'TYPE1', 'PROP2': 'TYPE2', ... } } >> List of strings is fine when the values are strings. When they're not, >> the interface requires its users to parse strings, which is something we >> try hard to avoid in QAPI/QMP. > > Okay, then I think we can do this with flat union discriminated with > “type” (changing it to enum) : > boolean: [‘bool’] > string: [’str’] > number: ['NumRange’] where NumRange: {‘min’: uint64, ‘max’: uint64} > > Range form to handle numeric properties with no restrictions. > > Does this look reasonable to you? Yes, this is a reasonable way to do dynamic typing in QAPI. I still need to understand why you you dynamic types here. [...]
