From: "Winkler, Tomas" <tomas.winkler@intel.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: "linux-integrity@vger.kernel.org"
<linux-integrity@vger.kernel.org>,
"linux-security-module@vger.kernel.org"
<linux-security-module@vger.kernel.org>,
James Bottomley <James.Bottomley@HansenPartnership.com>,
"Struk, Tadeusz" <tadeusz.struk@intel.com>,
Stefan Berger <stefanb@linux.vnet.ibm.com>,
"Nayna Jain" <nayna@linux.ibm.com>,
Peter Huewe <peterhuewe@gmx.de>, "Jason Gunthorpe" <jgg@ziepe.ca>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
open list <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v5 16/17] tpm: take TPM chip power gating out of tpm_transmit()
Date: Fri, 9 Nov 2018 21:37:48 +0000 [thread overview]
Message-ID: <5B8DA87D05A7694D9FA63FD143655C1B9DA190F4@hasmsx108.ger.corp.intel.com> (raw)
In-Reply-To: <20181108230700.GA8038@linux.intel.com>
>
> On Thu, Nov 08, 2018 at 06:38:59PM +0000, Winkler, Tomas wrote:
> > > Call tpm_chip_start() and tpm_chip_stop() in
> > >
> > > * tpm_try_get_ops() and tpm_put_ops()
> > > * tpm_chip_register()
> > > * tpm2_del_space()
> > >
> > > And remove these calls from tpm_transmit(). The core reason for this
> > > change is that in tpm_vtpm_proxy a locality change requires a
> > > virtual TPM command (a command made up just for that driver).
> > >
> > I don't think you can do that, locality has to be request for each
> > command, as for example tboot can request higher locality any time.
>
> That could be a potential problem. How tboot intervention gets prevented
> without this patch?
As it was said, need to request locality and relinquish it for each command, I believe thought this is not required for client platforms only for servers.
>
> > Same for cmd_ready()/go_idle() powergatin, you will prevent the whole
> > platform entering power save state.
>
> Why would you want that in a middle of using the TPM anyway?
If I'm reading this patch correctly you do cmd_ready when tpm is opened, it doesn't mean there is a real traffic, so why to keep it awake.
Thanks
Tomas
next prev parent reply other threads:[~2018-11-09 21:37 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-08 14:15 [PATCH v5 00/17] Remove nested TPM operations Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 01/17] tpm: use tpm_buf in tpm_transmit_cmd() as the IO parameter Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 02/17] tpm: fix invalid return value in pubek_show() Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 03/17] tpm: return 0 from pcrs_show() when tpm1_pcr_read() fails Jarkko Sakkinen
2018-11-08 14:52 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 04/17] tpm: call tpm2_flush_space() on error in tpm_try_transmit() Jarkko Sakkinen
2018-11-08 14:55 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 05/17] tpm: print tpm2_commit_space() error inside tpm2_commit_space() Jarkko Sakkinen
2018-11-08 14:56 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 06/17] tpm: clean up tpm_try_transmit() error handling flow Jarkko Sakkinen
2018-11-08 14:59 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 07/17] tpm: declare struct tpm_header Jarkko Sakkinen
2018-11-08 15:02 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 08/17] tpm: access command header through struct in tpm_try_transmit() Jarkko Sakkinen
2018-11-08 15:03 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 09/17] tpm: move tpm_validate_commmand() to tpm2-space.c Jarkko Sakkinen
2018-11-08 17:03 ` Winkler, Tomas
2018-11-08 23:07 ` Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 10/17] tpm: encapsulate tpm_dev_transmit() Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 11/17] tpm: move TPM space code out of tpm_transmit() Jarkko Sakkinen
2018-11-08 15:16 ` Stefan Berger
2018-11-08 18:58 ` Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 12/17] tpm: remove @space from tpm_transmit() Jarkko Sakkinen
2018-11-08 15:18 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 13/17] tpm: use tpm_try_get_ops() in tpm-sysfs.c Jarkko Sakkinen
2018-11-08 15:26 ` Stefan Berger
2018-11-08 14:15 ` [PATCH v5 14/17] tpm: remove TPM_TRANSMIT_UNLOCKED flag Jarkko Sakkinen
2018-11-08 15:43 ` Stefan Berger
2018-11-08 19:02 ` Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 15/17] tpm: introduce tpm_chip_start() and tpm_chip_stop() Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 16/17] tpm: take TPM chip power gating out of tpm_transmit() Jarkko Sakkinen
2018-11-08 18:38 ` Winkler, Tomas
2018-11-08 23:07 ` Jarkko Sakkinen
2018-11-09 21:37 ` Winkler, Tomas [this message]
2018-11-13 11:12 ` Jarkko Sakkinen
2018-11-13 11:58 ` Winkler, Tomas
2018-11-13 15:52 ` Jarkko Sakkinen
2018-11-08 14:15 ` [PATCH v5 17/17] tpm: remove @flags from tpm_transmit() Jarkko Sakkinen
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