Re: [PATCH v7 11/17] target/s390x: Support protected key AES CBC for cpacf kmc instruction

[Harald Freudenberger <freude@linux.ibm.com>]

On 2026-06-18 08:08, Finn Callies wrote:
> On 17.06.26 11:48, Harald Freudenberger wrote:
>> Support the subfunctions CPACF_KMC_PAES_128, CPACF_KMC_PAES_192
>> and CPACF_KMC_PAES_256 for the cpacf kmc instruction.
>> 
>> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
>> Tested-by: Holger Dengler <dengler@linux.ibm.com>
> 
> With the suggested changes:
> 
> Reviewed-by: Finn Callies <fcallies@linux.ibm.com>
> 
>> ---
>>   target/s390x/gen-features.c      |   3 +
>>   target/s390x/tcg/cpacf.h         |   4 ++
>>   target/s390x/tcg/cpacf_aes.c     | 109 
>> +++++++++++++++++++++++++++++++
>>   target/s390x/tcg/crypto_helper.c |   7 ++
>>   4 files changed, 123 insertions(+)
>> 
>> diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
>> index 71e0e41d6e..074c53aecd 100644
>> --- a/target/s390x/gen-features.c
>> +++ b/target/s390x/gen-features.c
>> @@ -932,6 +932,9 @@ static uint16_t qemu_MAX[] = {
>>       S390_FEAT_KMC_AES_128,
>>       S390_FEAT_KMC_AES_192,
>>       S390_FEAT_KMC_AES_256,
>> +    S390_FEAT_KMC_EAES_128,
>> +    S390_FEAT_KMC_EAES_192,
>> +    S390_FEAT_KMC_EAES_256,
> 
> Again, either EAES -> PAES or EAES -> ENCRYPTED_AES
> 

Again - out of the scope of this patch series.

>>       S390_FEAT_KMCTR_AES_128,
>>       S390_FEAT_KMCTR_AES_192,
>>       S390_FEAT_KMCTR_AES_256,
> 
> [ snip ]
> 
>> diff --git a/target/s390x/tcg/cpacf_aes.c 
>> b/target/s390x/tcg/cpacf_aes.c
>> index bcfcf3b660..a6487261e1 100644
>> --- a/target/s390x/tcg/cpacf_aes.c
>> +++ b/target/s390x/tcg/cpacf_aes.c
>> @@ -620,3 +620,112 @@ int cpacf_paes_ecb(CPUS390XState *env, const int 
>> mmu_idx, uintptr_t ra,
>>         return !len ? 0 : 3;
>>   }
>> +
>> +int cpacf_paes_cbc(CPUS390XState *env, const int mmu_idx, uintptr_t 
>> ra,
>> +                   uint64_t param_addr, uint64_t *dst_ptr_reg,
>> +                   uint64_t *src_ptr_reg, uint64_t *src_len_reg,
>> +                   uint32_t type, uint8_t fc, uint8_t mod)
>> +{
> 
> [ snip ]
> 
>> +    /* fetch protected key from param block */
>> +    for (i = 0; i < keysize; i++) {
>> +        addr = wrap_address(env, param_addr + AES_BLOCK_SIZE + i);
>> +        key[i] = cpu_ldb_mmu(env, addr, oi, ra);
>> +    }
>> +    /* 'decrypt' the protected key */
>> +    for (i = 0; i < keysize; i++) {
>> +        key[i] ^= protkey_xor_pattern[i];
>> +    }
> 
> You would already benefit from the suggested outsourcing.
> 

Yep, done.

>> +
>> +    /* expand key */
>> +    if (mod) {
>> +        AES_set_decrypt_key(key, keysize * 8, &exkey);
>> +    } else {
>> +        AES_set_encrypt_key(key, keysize * 8, &exkey);
>> +    }
> 
> [ snip ]