Re: [PATCH v7 04/13] s390x: topology: implementating Store Topology System Information

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

On 5/24/22 12:59, Thomas Huth wrote:
> On 20/04/2022 13.57, Pierre Morel wrote:
>> The handling of STSI is enhanced with the interception of the
>> function code 15 for storing CPU topology.
>>
>> Using the objects built during the pluging of CPU, we build the
> 
> s/pluging/plugging/
> 
>> SYSIB 15_1_x structures.
>>
>> With this patch the maximum MNEST level is 2, this is also
>> the only level allowed and only SYSIB 15_1_2 will be built.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
> ...
>> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
>> index f6969b76c5..a617c943ff 100644
>> --- a/target/s390x/cpu.h
>> +++ b/target/s390x/cpu.h
>> @@ -889,4 +889,5 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
>>   #include "exec/cpu-all.h"
>> +void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar);
>>   #endif
> 
> Please keep an empty line before the #endif

OK

> 
>> diff --git a/target/s390x/cpu_topology.c b/target/s390x/cpu_topology.c
>> new file mode 100644
>> index 0000000000..7f6db18829
>> --- /dev/null
>> +++ b/target/s390x/cpu_topology.c
>> @@ -0,0 +1,112 @@
>> +/*
>> + * QEMU S390x CPU Topology
>> + *
>> + * Copyright IBM Corp. 2021
> 
> 2022 ?
:) yes

> 
>> + * Author(s): Pierre Morel <pmorel@linux.ibm.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or 
>> (at
>> + * your option) any later version. See the COPYING file in the top-level
>> + * directory.
>> + */
> ...
>> +void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar)
>> +{
>> +    const MachineState *machine = MACHINE(qdev_get_machine());
>> +    void *p;
>> +    int ret, cc;
>> +
>> +    /*
>> +     * Until the SCLP STSI Facility reporting the MNEST value is used,
>> +     * a sel2 value of 2 is the only value allowed in STSI 15.1.x.
>> +     */
>> +    if (sel2 != 2) {
>> +        setcc(cpu, 3);
>> +        return;
>> +    }
>> +
>> +    p = g_malloc0(TARGET_PAGE_SIZE);
>> +
>> +    setup_stsi(machine, p, 2);
>> +
>> +    if (s390_is_pv()) {
>> +        ret = s390_cpu_pv_mem_write(cpu, 0, p, TARGET_PAGE_SIZE);
>> +    } else {
>> +        ret = s390_cpu_virt_mem_write(cpu, addr, ar, p, 
>> TARGET_PAGE_SIZE);
>> +    }
>> +    cc = ret ? 3 : 0;
>> +    setcc(cpu, cc);
> 
> Just a matter of taste (i.e. keep it if you like) - but you could 
> scratch the cc variable in this function by just doing:
> 
>      setcc(cpu, ret ? 3 : 0);
> 

OK I can do this.

Thanks
Pierre

>> +    g_free(p);
>> +}
>> +
> 
>   Thomas
> 

-- 
Pierre Morel
IBM Lab Boeblingen