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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 20 Dec 2018 13:08:46 +0100
Message-ID: <CAK8P3a3QatXPYgDzZkUpxwHh5HJw5-XWA6VoyxW6Y9UAnzS=tQ@mail.gmail.com>
Subject: Re: x86/sgx: uapi change proposal
To:     jethro@fortanix.com
Cc:     Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        sean.j.christopherson@intel.com, "H. Peter Anvin" <hpa@zytor.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-sgx@vger.kernel.org, Andy Lutomirski <luto@amacapital.net>,
        Josh Triplett <josh@joshtriplett.org>,
        haitao.huang@linux.intel.com, greg@enjellic.com
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On Wed, Dec 19, 2018 at 10:26 AM Jethro Beekman <jethro@fortanix.com> wrote:
>
> On 2018-12-19 13:28, Jarkko Sakkinen wrote:
> > /**
> >  * struct sgx_enclave_add_page - parameter structure for the
> >  *                               %SGX_IOC_ENCLAVE_ADD_PAGE ioctl
> >  * @eclave_fd:        file handle to the enclave address space
> >  * @src:      address for the page data
> >  * @secinfo:  address for the SECINFO data
> >  * @mrmask:   bitmask for the measured 256 byte chunks
> >  */
> > struct sgx_enclave_add_page {
> >       __u64   enclave_fd;
> >       __u64   src;
> >       __u64   secinfo;
> >       __u16   mrmask;
> > } __attribute__((__packed__));
>
> Wouldn't you just pass enclave_fd as the ioctl fd parameter?
>
> How to specify the address of the page that is being added?

One more comment about the structure: I would generally recommend
against packing structures like this. Instead just extend the mrmask
member to 64 bits as well.

      Arnd