Re: [PATCH v21 08/20] qapi/s390x/cpu topology: set-cpu-topology qmp command

[Pierre Morel <pmorel@linux.ibm.com>]

On 7/4/23 14:53, Thomas Huth wrote:
> On 30/06/2023 11.17, Pierre Morel wrote:
>> The modification of the CPU attributes are done through a monitor
>> command.
>>
>> It allows to move the core inside the topology tree to optimize
>> the cache usage in the case the host's hypervisor previously
>> moved the CPU.
>>
>> The same command allows to modify the CPU attributes modifiers
>> like polarization entitlement and the dedicated attribute to notify
>> the guest if the host admin modified scheduling or dedication of a vCPU.
>>
>> With this knowledge the guest has the possibility to optimize the
>> usage of the vCPUs.
>>
>> The command has a feature unstable for the moment.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
> ...
>> diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
>> index 1af70a5049..dfc4cb42a4 100644
>> --- a/hw/s390x/cpu-topology.c
>> +++ b/hw/s390x/cpu-topology.c
>> @@ -23,6 +23,7 @@
>>   #include "target/s390x/cpu.h"
>>   #include "hw/s390x/s390-virtio-ccw.h"
>>   #include "hw/s390x/cpu-topology.h"
>> +#include "qapi/qapi-commands-machine-target.h"
>>     /*
>>    * s390_topology is used to keep the topology information.
>> @@ -260,6 +261,29 @@ static bool s390_topology_check(uint16_t 
>> socket_id, uint16_t book_id,
>>       return true;
>>   }
>>   +/**
>> + * s390_topology_need_report
>> + * @cpu: Current cpu
>> + * @drawer_id: future drawer ID
>> + * @book_id: future book ID
>> + * @socket_id: future socket ID
>> + * @entitlement: future entitlement
>> + * @dedicated: future dedicated
>> + *
>> + * A modified topology change report is needed if the topology
>> + * tree or the topology attributes change.
>> + */
>> +static bool s390_topology_need_report(S390CPU *cpu, int drawer_id,
>> +                                   int book_id, int socket_id,
>> +                                   uint16_t entitlement, bool 
>> dedicated)
>> +{
>> +    return cpu->env.drawer_id != drawer_id ||
>> +           cpu->env.book_id != book_id ||
>> +           cpu->env.socket_id != socket_id ||
>> +           cpu->env.entitlement != entitlement ||
>> +           cpu->env.dedicated != dedicated;
>> +}
>> +
>>   /**
>>    * s390_update_cpu_props:
>>    * @ms: the machine state
>> @@ -329,3 +353,113 @@ void s390_topology_setup_cpu(MachineState *ms, 
>> S390CPU *cpu, Error **errp)
>>       /* topology tree is reflected in props */
>>       s390_update_cpu_props(ms, cpu);
>>   }
>> +
>> +static void s390_change_topology(uint16_t core_id,
>> +                                 bool has_socket_id, uint16_t 
>> socket_id,
>> +                                 bool has_book_id, uint16_t book_id,
>> +                                 bool has_drawer_id, uint16_t 
>> drawer_id,
>> +                                 bool has_entitlement,
>> +                                 CpuS390Entitlement entitlement,
>> +                                 bool has_dedicated, bool dedicated,
>> +                                 Error **errp)
>> +{
>> +    MachineState *ms = current_machine;
>> +    int old_socket_entry;
>> +    int new_socket_entry;
>> +    bool report_needed;
>> +    S390CPU *cpu;
>> +    ERRP_GUARD();
>> +
>> +    cpu = s390_cpu_addr2state(core_id);
>> +    if (!cpu) {
>> +        error_setg(errp, "Core-id %d does not exist!", core_id);
>> +        return;
>> +    }
>> +
>> +    /* Get attributes not provided from cpu and verify the new 
>> topology */
>> +    if (!has_socket_id) {
>> +        socket_id = cpu->env.socket_id;
>> +    }
>> +    if (!has_book_id) {
>> +        book_id = cpu->env.book_id;
>> +    }
>> +    if (!has_drawer_id) {
>> +        drawer_id = cpu->env.drawer_id;
>> +    }
>> +    if (!has_dedicated) {
>> +        dedicated = cpu->env.dedicated;
>> +    }
>> +
>> +    /*
>> +     * When the user specifies the entitlement as 'auto' on the 
>> command line,
>> +     * qemu will set the entitlement as:
>> +     * Medium when the CPU is not dedicated.
>> +     * High when dedicated is true.
>> +     */
>> +    if (!has_entitlement || (entitlement == 
>> S390_CPU_ENTITLEMENT_AUTO)) {
>> +        if (dedicated) {
>> +            entitlement = S390_CPU_ENTITLEMENT_HIGH;
>> +        } else {
>> +            entitlement = S390_CPU_ENTITLEMENT_MEDIUM;
>> +        }
>> +    }
>> +
>> +    if (!s390_topology_check(socket_id, book_id, drawer_id,
>> +                             entitlement, dedicated, errp))
>> +        return;
>
> Missing curly braces here.
> Not sure why this isn't caught by checkpatch.pl properly :-(
>
>  Thomas
>
Yes indeed.

I add the curly braces.

Thanks

Pierre