Re: [PATCH v5 0/5] Lazy flush for the auth session

[Stefan Berger]

On 9/21/24 8:08 AM, Jarkko Sakkinen wrote:
> This patch set aims to fix:
> https://bugzilla.kernel.org/show_bug.cgi?id=219229.
>
> The baseline for the series is the v6.11 tag.

I was testing this with 6.12-rc1 on ppc64/kvm + vtpm boot time from 
pressing return on grub until login prompt appears while using an IMA 
measure policy:

with HMAC2: 36s
with HMAC2+this series: 29s
without HMAC2: 28s

Looks good to me, though using a hardware TPM would probably be more 
critical in this type of measurement.

> v4:
> https://lore.kernel.org/linux-integrity/20240918203559.192605-1-jarkko@xxxxxxxxxx/
> v3:
> https://lore.kernel.org/linux-integrity/20240917154444.702370-1-jarkko@xxxxxxxxxx/
> v2:
> https://lore.kernel.org/linux-integrity/20240916110714.1396407-1-jarkko@xxxxxxxxxx/
> v1:
> https://lore.kernel.org/linux-integrity/20240915180448.2030115-1-jarkko@xxxxxxxxxx/
>
> Jarkko Sakkinen (5):
>    tpm: Return on tpm2_create_null_primary() failure
>    tpm: Implement tpm2_load_null() rollback
>    tpm: flush the null key only when /dev/tpm0 is accessed
>    tpm: Allocate chip->auth in tpm2_start_auth_session()
>    tpm: flush the auth session only when /dev/tpm0 is open
>
>   drivers/char/tpm/tpm-chip.c       |  14 ++++
>   drivers/char/tpm/tpm-dev-common.c |   8 +++
>   drivers/char/tpm/tpm-interface.c  |  10 ++-
>   drivers/char/tpm/tpm2-cmd.c       |   3 +
>   drivers/char/tpm/tpm2-sessions.c  | 109 ++++++++++++++++++------------
>   include/linux/tpm.h               |   2 +
>   6 files changed, 102 insertions(+), 44 deletions(-)