Re: [RFC PATCH v4 5/5] s390: implementing CHSC SEI for AP config change

[Rorie Reyes <rreyes@linux.ibm.com>]

[-- Attachment #1: Type: text/plain, Size: 2698 bytes --]


On 3/17/25 9:41 AM, Thomas Huth wrote:
> On 11/03/2025 16.16, Rorie Reyes wrote:
>> Handle interception of the CHSC SEI instruction for requests
>> indicating the guest's AP configuration has changed.
>>
>> Signed-off-by: Rorie Reyes <rreyes@linux.ibm.com>
>> Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
>> Tested-by: Anthony Krowiak <akrowiak@linux.ibm.com>
>> ---
>>   target/s390x/ioinst.c | 11 +++++++++--
>>   1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
>> index a944f16c25..f061c6db14 100644
>> --- a/target/s390x/ioinst.c
>> +++ b/target/s390x/ioinst.c
>> @@ -17,6 +17,7 @@
>>   #include "trace.h"
>>   #include "hw/s390x/s390-pci-bus.h"
>>   #include "target/s390x/kvm/pv.h"
>> +#include "hw/s390x/ap-bridge.h"
>>     /* All I/O instructions but chsc use the s format */
>>   static uint64_t get_address_from_regs(CPUS390XState *env, uint32_t 
>> ipb,
>> @@ -573,13 +574,19 @@ out:
>>     static int chsc_sei_nt0_get_event(void *res)
>>   {
>> -    /* no events yet */
>> +    if (s390_has_feat(S390_FEAT_AP)) {
>> +        return ap_chsc_sei_nt0_get_event(res);
>> +    }
>> +
>>       return 1;
>>   }
>>     static int chsc_sei_nt0_have_event(void)
>>   {
>> -    /* no events yet */
>> +    if (s390_has_feat(S390_FEAT_AP)) {
>> +        return ap_chsc_sei_nt0_have_event();
>> +    }
>> +
>>       return 0;
>>   }
>
>  Hi!
>
> This unfortunately fails to link when configuring QEMU with the 
> "--without-default-devices" configure switch:
>
> /usr/bin/ld: libqemu-s390x-softmmu.a.p/target_s390x_ioinst.c.o: in 
> function `ioinst_handle_chsc':
> /tmp/qemu-mini/target/s390x/ioinst.c:587:(.text+0x1ce1): undefined 
> reference to `ap_chsc_sei_nt0_have_event'
> /usr/bin/ld: /tmp/qemu-mini/target/s390x/ioinst.c:578:(.text+0x1d1c): 
> undefined reference to `ap_chsc_sei_nt0_get_event'
> collect2: error: ld returned 1 exit status
>
> I guess you have to rather use some callback mechanism, stubs or 
> #ifdefs here instead.
>
>  Thomas
>
Hey Thomas,

Sorry for the delay. I was trying out some ways to resolve this issue 
but I'm not sure what I would use for the macro name if I were to

go the #ifdef route. I had something roughly like this but it wasn't 
working. Would you have any recommendations?

static int chsc_sei_nt0_get_event(void *res) { #ifdef 
HW_S390X_AP_BRIDGE_H if (s390_has_feat(S390_FEAT_AP)) { return 
ap_chsc_sei_nt0_get_event(res); } #endif return 1; } static int 
chsc_sei_nt0_have_event(void) { #ifdef HW_S390X_AP_BRIDGE_H if 
(s390_has_feat(S390_FEAT_AP)) { return ap_chsc_sei_nt0_have_event(); } 
#endif return 0; }

[-- Attachment #2: Type: text/html, Size: 4617 bytes --]