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Date:   Wed, 19 Dec 2018 07:00:47 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Sean Christopherson <sean.j.christopherson@intel.com>
Cc:     Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>, X86 ML <x86@kernel.org>,
        Platform Driver <platform-driver-x86@vger.kernel.org>,
        linux-sgx@vger.kernel.org, nhorman@redhat.com,
        npmccallum@redhat.com, "Ayoun, Serge" <serge.ayoun@intel.com>,
        shay.katz-zamir@intel.com,
        Haitao Huang <haitao.huang@linux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Svahn, Kai" <kai.svahn@intel.com>, mark.shanahan@intel.com,
        Suresh Siddha <suresh.b.siddha@intel.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Darren Hart <dvhart@infradead.org>,
        Andy Shevchenko <andy@infradead.org>,
        "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" 
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v17 18/23] platform/x86: Intel SGX driver
Message-ID: <20181219050047.GC14295@linux.intel.com>
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On Tue, Dec 18, 2018 at 10:53:49AM -0800, Sean Christopherson wrote:
> What if we re-organize the ioctls in such a way that we leave open the
> possibility of allocating raw EPC for KVM via /dev/sgx?  I'm not 100%
> positive this approach will work[1], but conceptually it fits well with
> KVM's memory model, e.g. KVM is aware of the GPA<->HVA association but
> generally speaking doesn't know what's physically backing each memory
> region.

Why would you want to pass EPC through user space to KVM rather than
KVM allocating it through kernel interfaces?

> Tangentially related, I think we should support allocating multiple
> enclaves from a single /dev/sgx fd, i.e. a process shouldn't have to
> open /dev/sgx every time it wants to create a new enclave.

I'm fine with this. It just requires to create anon inode. I'll just
add a new field called 'enclave_fd' to struct sgx_enclave_create and
that's all.

I think I have otherwise ingredients for v19 ready except where to swap.

/Jarkko