Re: [PATCH v9 01/11] KEYS: trusted: Use get_random-fallback for TPM

[Jarkko Sakkinen]

On Mon, Mar 23, 2026 at 07:34:39AM +0200, Jarkko Sakkinen wrote:
> On Mon, Mar 23, 2026 at 07:26:38AM +0200, Jarkko Sakkinen wrote:
> > On Thu, Mar 19, 2026 at 10:28:03AM -0400, Mimi Zohar wrote:
> > > On Wed, 2026-03-18 at 10:36 -0700, Chris Fenner wrote:
> > > > Apologies if my long message derailed this discussion. I meant to
> > > > support Mimi's concern here and project a future vision where
> > > > TCG_TPM2_HMAC doesn't conflict with other features.
> > > > 
> > > > More concisely, I think that:
> > > > 
> > > > > tpm2_get_random() is costly when TCG_TPM2_HMAC is enabled
> > > > 
> > > > is not a compelling argument for removing TPM as an RNG source,
> > > > because TCG_TPM2_HMAC is known to have poor performance already
> > > > anyway.
> > > 
> > > Agreed.  Thanks, Chris!  FYI, we raised concerns about IMA performance with the
> > > TPM HMAC and encrypted feature while it was being developed. James had some
> > > ideas, at the time, as to how to resolve the performance issue for IMA.  Yet it
> > > was upstreamed without those changes and with CONFIG_TCG_TPM2_HMAC enabled by
> > > default on x86 systems.
> > > 
> > > Jarkko has queued this patch in the "queue" branch, without indicating whether
> > > it will eventually be upstreamed or not.
> > 
> > Yes and there's been multiple months of time to comment this and I
> > backed up the patch set there, which is not same as applying it.
> 
> There's quite many other patches in that patch set also in the queue
> branch. This was largeriy past life for me when these comments came.
> Really don't understand what is suddenly going on tnh and for one
> not that interesting patch.

Underlined: not a queue to anywhere. I can rename it something else,
did not really think about the name when I created the branch.

BR, Jarkkko