On Thu Nov 7, 2024 at 4:48 AM EET, Mimi Zohar wrote: > On Thu, 2024-11-07 at 02:51 +0200, Jarkko Sakkinen wrote: > > On Thu Nov 7, 2024 at 2:47 AM EET, Jarkko Sakkinen wrote: > > > From: Mimi Zohar <zohar@xxxxxxxxxxxxx> > > > > > > The initial encrypted HMAC session feature added TPM bus encryption to > > > various in-kernel TPM operations. This can cause performance bottlenecks > > > with IMA, as it heavily utilizes PCR extend operations. > > The patch Subject line and problem description aren't quite right. In the case > of TPM pcr_extend, the session isn't being encrypted, only HMAC'ed. According > to James, it's the HMAC itself that is causing the performance degradation. I > would remove the word "encrypted" throughout. I have to say I disagree with that. Encryption is the feature we get with HMAC and is more understandable for most. HMAC is implemnetation detail. BR, Jarkko
