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Subject: Re: [PATCH v2 1/4] s390/pkey: Use -ENODEV instead of -EOPNOTSUPP
To:     David Hildenbrand <david@redhat.com>, linux-kernel@vger.kernel.org
Cc:     linux-s390@vger.kernel.org, linux-crypto@vger.kernel.org,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Cornelia Huck <cohuck@redhat.com>
References: <20190612102248.18903-1-david@redhat.com>
 <20190612102248.18903-2-david@redhat.com>
 <7f313d87-f9ea-e291-49e2-8da29cf41680@linux.ibm.com>
 <53936c66-ca09-98a7-4c3c-eae8c6024887@redhat.com>
From:   Harald Freudenberger <freude@linux.ibm.com>
Date:   Wed, 12 Jun 2019 13:07:50 +0200
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On 12.06.19 12:41, David Hildenbrand wrote:
> On 12.06.19 12:39, Harald Freudenberger wrote:
>> On 12.06.19 12:22, David Hildenbrand wrote:
>>> systemd-modules-load.service automatically tries to load the pkey module
>>> on systems that have MSA.
>>>
>>> Pkey also requires the MSA3 facility and a bunch of subfunctions.
>>> Failing with -EOPNOTSUPP makes "systemd-modules-load.service" fail on
>>> any system that does not have all needed subfunctions. For example,
>>> when running under QEMU TCG (but also on systems where protected keys
>>> are disabled via the HMC).
>>>
>>> Let's use -ENODEV, so systemd-modules-load.service properly ignores
>>> failing to load the pkey module because of missing HW functionality.
>>>
>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>> Signed-off-by: David Hildenbrand <david@redhat.com>
>>> ---
>>>  drivers/s390/crypto/pkey_api.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c
>>> index 45eb0c14b880..ddfcefb47284 100644
>>> --- a/drivers/s390/crypto/pkey_api.c
>>> +++ b/drivers/s390/crypto/pkey_api.c
>>> @@ -1695,15 +1695,15 @@ static int __init pkey_init(void)
>>>  	 * are able to work with protected keys.
>>>  	 */
>>>  	if (!cpacf_query(CPACF_PCKMO, &pckmo_functions))
>>> -		return -EOPNOTSUPP;
>>> +		return -ENODEV;
>>>  
>>>  	/* check for kmc instructions available */
>>>  	if (!cpacf_query(CPACF_KMC, &kmc_functions))
>>> -		return -EOPNOTSUPP;
>>> +		return -ENODEV;
>>>  	if (!cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
>>>  	    !cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
>>>  	    !cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256))
>>> -		return -EOPNOTSUPP;
>>> +		return -ENODEV;
>>>  
>>>  	pkey_debug_init();
>>>  
>> You missed one match in this file. Function pkey_clr2protkey()
>> also does a cpacf_test_func() and may return -EOPNOTSUPP.
>> I checked the call chain, it's save to change the returncode there also.
> That's unrelated to module loading (if I am not wrong), shall we still
> include this change here?
>
> Thanks!
That would be nice.
However, I agree it is not related to module loading.
>
>> If done, Thanks and add my
>> reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
>>
>