Re: [PATCH v4] tpm_crb: request and relinquish locality 0

[Jerry Snitselaar]

----- Original Message -----
> From: "Jarkko Sakkinen" <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> To: "Jerry Snitselaar" <jsnitsel@xxxxxxxxxx>, "gang wei" <gang.wei@xxxxxxxxx>
> Cc: "Jarkko Sakkinen" <jarkko.sakkinen@xxxxxx>, tpmdd-devel@xxxxxxxxxxxxxxxxxxxxx,
> linux-security-module@xxxxxxxxxxxxxxx, "Peter Huewe" <peterhuewe@xxxxxx>, "Marcel Selhorst" <tpmdd@xxxxxxxxxxxx>,
> "Jason Gunthorpe" <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>, "open list" <linux-kernel@xxxxxxxxxxxxxxx>
> Sent: Sunday, March 26, 2017 3:52:39 AM
> Subject: Re: [PATCH v4] tpm_crb: request and relinquish locality 0
> 
> On Sat, Mar 25, 2017 at 09:52:11PM +0200, Jarkko Sakkinen wrote:
> > On Fri, Mar 24, 2017 at 11:25:57AM -0700, Jerry Snitselaar wrote:
> > > 
> > > Jarkko Sakkinen @ 2017-03-24 10:10 GMT:
> > > 
> > > > This commit adds support for requesting and relinquishing locality 0 in
> > > > tpm_crb for the course of command transmission.
> > > >
> > > > In order to achieve this, two new callbacks are added to struct
> > > > tpm_class_ops:
> > > >
> > > > - request_locality
> > > > - relinquish_locality
> > > >
> > > > With CRB interface you first set either requestAccess or relinquish bit
> > > > from TPM_LOC_CTRL_x register and then wait for locAssigned and
> > > > tpmRegValidSts bits to be set in the TPM_LOC_STATE_x register.
> > > >
> > > > The reason why were are doing this is to make sure that the driver
> > > > will work properly with Intel TXT that uses locality 2. There's no
> > > > explicit guarantee that it would relinquish this locality. In more
> > > > general sense this commit enables tpm_crb to be a well behaving
> > > > citizen in a multi locality environment.
> > > >
> > > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > > 
> > > Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> > > Tested-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> > > 
> > > Tested on kabylake system that was hitting issues with earlier
> > > iteration. Still don't have platform to test it dealing with
> > > multi-locality enviroment.
> > 
> > I believe Jimmy (Gang Wei) has done such testing. Jimmy can you confirm
> > and possibly do re-test (there's a locality branch in my tree to ease
> > the testing) so that we could land this one?
> > 
> > /Jarkko
> 
> I applied this to my master and next branches.
> 
> /Jarkko
> 

Hi Jarkko,

The patch applied to next and master doesn't have the assignment moved
inside the mutex.