Re: [PATCH 1/3] tpm: Disable TCG_TPM2_HMAC by default

From: Vitor Soares
Date: Wed May 22 2024 - 04:19:11 EST


On Tue, 2024-05-21 at 08:33 -0400, James Bottomley wrote:
> On Tue, 2024-05-21 at 10:10 +0300, Jarkko Sakkinen wrote:
> > This benchmark could be done in user space using /dev/tpm0.
>
> Let's actually try that.  If you have the ibmtss installed, the command
> to time primary key generation from userspace on your tpm is
>
> time tsscreateprimary -hi n -ecc nistp256
>
>
> And just for chuckles and grins, try it in the owner hierarchy as well
> (sometimes slow TPMs cache this)
>
> time tsscreateprimary -hi o -ecc nistp256
>
> And if you have tpm2 tools, the above commands should be:
>
> time tpm2_createprimary -C n -G ecc256
> time tpm2_createprimary -C o -G ecc256
>
> James
>
>

Testing on an arm64 platform I get the following results.

hmac disabled:
time modprobe tpm_tis_spi
real 0m2.776s
user 0m0.006s
sys 0m0.015s

time tpm2_createprimary -C n -G ecc256
real 0m0.686s
user 0m0.044s
sys 0m0.025s

time tpm2_createprimary -C o -G ecc256
real 0m0.638s
user 0m0.048s
sys 0m0.009s


hmac enabled:
time modprobe tpm_tis_spi
real 8m5.840s
user 0m0.005s
sys 0m0.018s


time tpm2_createprimary -C n -G ecc256
real 5m27.678s
user 0m0.059s
sys 0m0.009s

(after first command)
real 0m0.395s
user 0m0.040s
sys 0m0.015s

time tpm2_createprimary -C o -G ecc256
real 0m0.418s
user 0m0.049s
sys 0m0.009s

hmac enabled + patches applied
time modprobe tpm_tis_spi
real 8m6.663s
user 0m0.000s
sys 0m0.021s


time tpm2_createprimary -C n -G ecc256
real 7m24.662s
user 0m0.048s
sys 0m0.022s

(after first command)
real 0m0.395s
user 0m0.047s
sys 0m0.009s

time tpm2_createprimary -C o -G ecc256
real 0m0.404s
user 0m0.046s
sys 0m0.012s


Regards,
Vitor Soares