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Date:   Thu, 20 Dec 2018 15:19:55 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Andy Lutomirski <luto@kernel.org>
Cc:     Sean Christopherson <sean.j.christopherson@intel.com>,
        Jethro Beekman <jethro@fortanix.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "x86@kernel.org" <x86@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-sgx@vger.kernel.org" <linux-sgx@vger.kernel.org>,
        Josh Triplett <josh@joshtriplett.org>,
        Haitao Huang <haitao.huang@linux.intel.com>,
        "Dr . Greg Wettstein" <greg@enjellic.com>
Subject: Re: x86/sgx: uapi change proposal
Message-ID: <20181220131955.GB4848@linux.intel.com>
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On Thu, Dec 20, 2018 at 03:12:13PM +0200, Jarkko Sakkinen wrote:
> On Thu, Dec 20, 2018 at 12:32:04PM +0200, Jarkko Sakkinen wrote:
> > On Wed, Dec 19, 2018 at 06:58:48PM -0800, Andy Lutomirski wrote:
> > > Can one of you explain why SGX_ENCLAVE_CREATE is better than just
> > > opening a new instance of /dev/sgx for each encalve?
> > 
> > I think that fits better to the SCM_RIGHTS scenario i.e. you could send
> > the enclav to a process that does not have necessarily have rights to
> > /dev/sgx. Gives more robust environment to configure SGX.
> 
> My only open for the implementation is where to swap? If it is a VMA,
> whose VMA?
> 
> Please share your views here. Not a blocker for me to work on the
> implementation, though. I'll use a private shmem file up until there
> is a better option.
> 
> This ioctl API discussion is kind of meaningless for me ATM because it
> does not have that much effect to the internals even if it wouldn't be
> perfect in v19. Very trival to change.

Oops, and after sending I realized that I started this thread asking
comments about the API (I think I mentioned swapping though too) :-) The
feedback has been valuable and I gained the required understanding about
enclave_fd but I think that now the things have been saturated to minor
details.

Appreciate all the feedback so far. Sorry for a bit harsh statement.

/Jarkko