Re: [PATCH 08/12] crypto: caam - support crypto_engine framework for SKCIPHER algorithms

[Bastian Krause <bst@pengutronix.de>]

Hi,

On 12/11/19 1:20 PM, Iuliana Prodan wrote:
> On 12/10/2019 5:27 PM, Bastian Krause wrote:
>> On 11/17/19 11:30 PM, Iuliana Prodan wrote:
>>> Integrate crypto_engine into CAAM, to make use of the engine queue.
>>> Add support for SKCIPHER algorithms.
>>>
>>> This is intended to be used for CAAM backlogging support.
>>> The requests, with backlog flag (e.g. from dm-crypt) will be listed
>>> into crypto-engine queue and processed by CAAM when free.
>>> This changes the return codes for caam_jr_enqueue:
>>> -EINPROGRESS if OK, -EBUSY if request is backlogged,
>>> -ENOSPC if the queue is full, -EIO if it cannot map the caller's
>>> descriptor, -EINVAL if crypto_tfm not supported by crypto_engine.
>>>
>>> Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
>>> Signed-off-by: Franck LENORMAND <franck.lenormand@nxp.com>
>>> Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
>>> ---
>>>   drivers/crypto/caam/Kconfig   |  1 +
>>>   drivers/crypto/caam/caamalg.c | 84 +++++++++++++++++++++++++++++++++++--------
>>>   drivers/crypto/caam/intern.h  |  2 ++
>>>   drivers/crypto/caam/jr.c      | 51 ++++++++++++++++++++++++--
>>>   4 files changed, 122 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
>>> index 87053e4..1930e19 100644
>>> --- a/drivers/crypto/caam/Kconfig
>>> +++ b/drivers/crypto/caam/Kconfig
>>> @@ -33,6 +33,7 @@ config CRYPTO_DEV_FSL_CAAM_DEBUG
>>>   
> ...
>>>   
>>> +static int skcipher_do_one_req(struct crypto_engine *engine, void *areq)
>>> +{
>>> +	struct skcipher_request *req = skcipher_request_cast(areq);
>>> +	struct caam_ctx *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
>>> +	struct caam_skcipher_req_ctx *rctx = skcipher_request_ctx(req);
>>> +	struct caam_jr_request_entry *jrentry;
>>> +	u32 *desc = rctx->edesc->hw_desc;
>>> +	int ret;
>>> +
>>> +	jrentry = &rctx->edesc->jrentry;
>>> +	jrentry->bklog = true;
>>> +
>>> +	ret = caam_jr_enqueue_no_bklog(ctx->jrdev, desc,
>>> +				       rctx->skcipher_op_done, jrentry);
>>> +
>>> +	if (ret != -EINPROGRESS) {
>>> +		skcipher_unmap(ctx->jrdev, rctx->edesc, req);
>>> +		kfree(rctx->edesc);
>>> +	} else {
>>> +		ret = 0;
>>> +	}
>>> +
>>> +	return ret;
>>
>> While testing this on a i.MX6 DualLite I see -ENOSPC being returned here
>> after a couple of GiB of data being encrypted (via dm-crypt with LUKS
>> extension). This results in these messages from crypto_engine:
>>
>>    caam_jr 2101000.jr0: Failed to do one request from queue: -28
>>
>> And later..
>>
>>    Buffer I/O error on device dm-0, logical block 59392
>>    JBD2: Detected IO errors while flushing file data on dm-0-8
>>
>> Reproducible with something like this:
>>
>>    echo "testkey" | cryptsetup luksFormat \
>>      --cipher=aes-cbc-essiv:sha256 \
>>      --key-file=- \
>>      --key-size=256 \
>>      /dev/mmcblk1p8
>>    echo "testkey" | cryptsetup open \
>>      --type luks \
>>      --key-file=- \
>>      /dev/mmcblk1p8 data
>>
>>    mkfs.ext4 /dev/mapper/data
>>    mount /dev/mapper/data /mnt
>>
>>    set -x
>>    while [ true ]; do
>>      dd if=/dev/zero of=/mnt/big_file bs=1M count=1024
>>      sync
>>    done
>>
>> Any ideas?
>>
> 
> Thanks for testing this!

Sure :)

> I reproduced this issue on imx6dl, _but_ only with the bypass sw queue 
> patch. It only reproduces on some targets, e.g. on imx7d I don't get the 
> -ENOSPC error. So, I believe there is a timing issue between 
> crypto-engine and CAAM driver, both sending requests to CAAM hw.
> I'm debugging this and I'll let you know my findings.

I can't even use this without the "crypto: caam - bypass crypto-engine
sw queue, if empty". The mkfs.ext4 command does not even finish and I
see hung task warnings. Am I holding it wrong?

Regards,
Bastian

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