From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: Re: [PATCH v2 6/7] tpm: expose spaces via a device link /dev/tpms Date: Fri, 24 Feb 2017 19:39:22 +0200 Message-ID: <20170224173922.qwuhfxeitbyct52o@intel.com> References: <20170216192529.25467-1-jarkko.sakkinen@linux.intel.com> <20170216192529.25467-7-jarkko.sakkinen@linux.intel.com> <20170223090917.jq7thil5ggjmagil@intel.com> <1487941328.2249.23.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1487941328.2249.23.camel@HansenPartnership.com> Sender: owner-linux-security-module@vger.kernel.org To: James Bottomley Cc: tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, dhowells@redhat.com, Peter Huewe , Marcel Selhorst , Jason Gunthorpe , open list List-Id: tpmdd-devel@lists.sourceforge.net On Fri, Feb 24, 2017 at 08:02:08AM -0500, James Bottomley wrote: > On Thu, 2017-02-23 at 11:09 +0200, Jarkko Sakkinen wrote: > > On Thu, Feb 16, 2017 at 09:25:19PM +0200, Jarkko Sakkinen wrote: > > > From: James Bottomley > > > > > > Currently the tpm spaces are not exposed to userspace. Make this > > > exposure via a separate device, which can now be opened multiple > > > times because each read/write transaction goes separately via the > > > space. > > > > > > Concurrency is protected by the chip->tpm_mutex for each read/write > > > transaction separately. The TPM is cleared of all transient > > > objects by the time the mutex is dropped, so there should be no > > > interference between the kernel and userspace. > > > Signed-off-by: James Bottomley < > > > > > > James.Bottomley@HansenPartnershp.com> > > > Reviewed-by: Jarkko Sakkinen > > Tested-by: Jarkko Sakkinen > > Thanks! > > > Nitpicking but I've been thinking about naming. What about calling > > the device as tpmrc0 as in resource context. I think that would be a > > better name than TPM space. > > Well the original name was tpmrm for TPM with Resource Manager. You > wanted it to be tpms for TPM with Spaces. > > I'm not entirely sold on the Resource Context name ... I think Resource Manager (because it's what the TCG calls it) or Spaces (because it's what all the code comments call it) are better. Resource Context sounds like what TPM2_SaveContext() creates for you rather than the interface. > > > You do not mix it up with namespaces and/or virtualization. With > > resource in front it cannot be easily mixed up with TPM contexts > > either. > > I'm a containers person. What this set of patches does is precisely OS > level virtualization in my book, so I don't think you need to pretend > it is't; and OS level virtualization is what a namespace does. The > only difference between this and the other kernel namespaces is that > you get a new namespace automatically when you open the device and you > can't enter an existing namespace. > > I think therefore that tpmns for TPM Namespace would be very > appropriate. Makes sense. We can go with tpmns. /Jarkko