Re: [PATCH] target/ppc: powerpc_excp: Guard ALIGNMENT interrupt with CONFIG_TCG

[Fabiano Rosas <farosas@linux.ibm.com>]

Cédric Le Goater <clg@kaod.org> writes:

> On 12/9/21 00:06, Fabiano Rosas wrote:
>> We cannot have TCG code in powerpc_excp because the function is called
>> from kvm-only code via ppc_cpu_do_interrupt:
>> 
>>   ../target/ppc/excp_helper.c:463:29: error: implicit declaration of
>>   function ‘cpu_ldl_code’ [-Werror=implicit-function-declaration]
>> 
>> Fortunately, the Alignment interrupt is not among the ones dispatched
>> from kvm-only code, so we can keep it out of the disable-tcg build for
>> now.
>> 
>> Fixes: 336e91f853 ("target/ppc: Move SPR_DSISR setting to powerpc_excp")
>> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
>> 
>> ---
>> 
>> Perhaps we could make powerpc_excp TCG only and have a separate
>> function that only knows the two interrupts that we use with KVM
>> (Program, Machine check). But for now this fix will do, I think.
>> ---
>>   target/ppc/excp_helper.c | 2 ++
>>   1 file changed, 2 insertions(+)
>> 
>> diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
>> index 17607adbe4..dcf22440cc 100644
>> --- a/target/ppc/excp_helper.c
>> +++ b/target/ppc/excp_helper.c
>> @@ -453,6 +453,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>>           }
>>           break;
>>       }
>> +#ifdef CONFIG_TCG
>>       case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
>>           /*
>>            * Get rS/rD and rA from faulting opcode.
>> @@ -464,6 +465,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>>               env->spr[SPR_DSISR] |= (insn & 0x03FF0000) >> 16;
>>           }
>>           break;
>> +#endif
>>       case POWERPC_EXCP_PROGRAM:   /* Program exception                        */
>>           switch (env->error_code & ~0xF) {
>>           case POWERPC_EXCP_FP:
>> 
>
> Shouldn't we move that code under ppc_cpu_do_unaligned_access ?

Well, it came from there initially. We could revert 336e91f853 and that
would fix the issue as well.

>
> Thanks,
>
> C.