Re: [PATCH 0/4] tpm: lazy flush for the session null key

[Pengyu Ma]

After applied your patches, the boot time is ~15 seconds.
Less than 20 sec, but still much more than 7 sec when disabling HMAC.

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On Mon, Sep 16, 2024 at 10:25 AM Pengyu Ma <mapengyu@xxxxxxxxx> wrote:
>
> Hi Jarkko,
>
> After applied your patches, the boot time is ~15 seconds.
> Less than 20 sec, but still much more than 7 sec when disabling HMAC.
>
> Thanks,
> Aaron
>
>
> On Mon, Sep 16, 2024 at 2:04 AM Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote:
>>
>> There is no load and flush the null key for every transaction. It only
>> needs to be flushed when user space accesses TPM. This postpones the
>> flush up to that point.
>>
>> The goal is to take the first step addressing [1]. Other performance
>> improvements are needed too but this is the most obvious one and
>> easiest to address.
>>
>> [1] https://bugzilla.kernel.org/show_bug.cgi?id=219229
>>
>> Jarkko Sakkinen (4):
>>   tpm: remove file header documentation from tpm2-sessions.c
>>   tpm: address tpm2_create_null_primary() return value
>>   tpm: address tpm2_create_primary() failure
>>   tpm: flush the session null key only when required
>>
>>  drivers/char/tpm/tpm-chip.c       |  13 ++++
>>  drivers/char/tpm/tpm-dev-common.c |   7 ++
>>  drivers/char/tpm/tpm-interface.c  |   9 ++-
>>  drivers/char/tpm/tpm2-cmd.c       |   3 +
>>  drivers/char/tpm/tpm2-sessions.c  | 115 ++++++++++--------------------
>>  include/linux/tpm.h               |   2 +
>>  6 files changed, 68 insertions(+), 81 deletions(-)
>>
>> --
>> 2.46.0
>>