linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Nathaniel McCallum <npmccallum@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-sgx@vger.kernel.org, akpm@linux-foundation.org,
	dave.hansen@intel.com, Neil Horman <nhorman@redhat.com>,
	"Huang, Haitao" <haitao.huang@intel.com>,
	andriy.shevchenko@linux.intel.com, tglx@linutronix.de, "Svahn,
	Kai" <kai.svahn@intel.com>,
	bp@alien8.de, Josh Triplett <josh@joshtriplett.org>,
	luto@kernel.org, kai.huang@intel.com,
	David Rientjes <rientjes@google.com>,
	"Xing, Cedric" <cedric.xing@intel.com>,
	Patrick Uiterwijk <puiterwijk@redhat.com>
Subject: Re: [PATCH v29 00/20] Intel SGX foundations
Date: Wed, 6 May 2020 15:14:22 -0700	[thread overview]
Message-ID: <20200506221422.GK3329@linux.intel.com> (raw)
In-Reply-To: <CAOASepPFe_ucuwe7JW_-+VBQ4=+sHqyGXOdA9kUbcYA_9=v0sA@mail.gmail.com>

On Wed, May 06, 2020 at 05:42:42PM -0400, Nathaniel McCallum wrote:
> Tested on Enarx. This requires a patch[0] for v29 support.
> 
> Tested-by: Nathaniel McCallum <npmccallum@redhat.com>
> 
> However, we did uncover a small usability issue. See below.
> 
> [0]: https://github.com/enarx/enarx/pull/507/commits/80da2352aba46aa7bc6b4d1fccf20fe1bda58662

...

> > * Disallow mmap(PROT_NONE) from /dev/sgx. Any mapping (e.g. anonymous) can
> >   be used to reserve the address range. Now /dev/sgx supports only opaque
> >   mappings to the (initialized) enclave data.
> 
> The statement "Any mapping..." isn't actually true.
> 
> Enarx creates a large enclave (currently 64GiB). This worked when we
> created a file-backed mapping on /dev/sgx/enclave. However, switching
> to an anonymous mapping fails with ENOMEM. We suspect this is because
> the kernel attempts to allocate all the pages and zero them but there
> is insufficient RAM available. We currently work around this by
> creating a shared mapping on /dev/zero.

Hmm, the kernel shouldn't actually allocate physical pages unless they're
written.  I'll see if I can reproduce.
 
> If we want to keep this mmap() strategy, we probably don't want to
> advise mmap(ANON) if it allocates all the memory for the enclave ahead
> of time, even if it won't be used. This would be wasteful.
> 
> OTOH, having to mmap("/dev/zero") seems a bit awkward.

  reply	other threads:[~2020-05-06 22:14 UTC|newest]

Thread overview: 83+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-21 21:52 [PATCH v29 00/20] Intel SGX foundations Jarkko Sakkinen
2020-04-21 21:52 ` [PATCH v29 01/20] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2020-04-21 21:52 ` [PATCH v29 02/20] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-04-21 21:52 ` [PATCH v29 03/20] x86/cpufeatures: x86/msr: Intel SGX Launch Control " Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 04/20] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 05/20] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 06/20] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 07/20] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 08/20] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 09/20] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 10/20] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 11/20] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-05-08 19:09   ` Sean Christopherson
2020-04-21 21:53 ` [PATCH v29 12/20] x86/sgx: Add provisioning Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 13/20] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 14/20] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-05-06 21:50   ` Sean Christopherson
2020-05-13 21:40     ` Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 15/20] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 16/20] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 17/20] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 18/20] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 19/20] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-04-21 21:53 ` [PATCH v29 20/20] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-04-22 16:48 ` [PATCH v29 00/20] Intel SGX foundations Connor Kuehl
2020-04-29  5:22   ` Jarkko Sakkinen
2020-04-26 16:57 ` Dr. Greg
2020-04-29  5:23   ` Jarkko Sakkinen
2020-04-29 15:14     ` Sean Christopherson
2020-04-30  3:59       ` Jarkko Sakkinen
2020-05-02 23:05         ` Dr. Greg
2020-05-03  0:48           ` Andy Lutomirski
2020-05-04  9:34             ` Dr. Greg
2020-04-29 15:30   ` Sean Christopherson
2020-05-08  0:40     ` Andy Lutomirski
2020-05-07  0:41   ` Thomas Gleixner
2020-05-08 19:02     ` Dr. Greg
2020-05-08 19:56       ` Sean Christopherson
2020-05-14  9:16         ` Dr. Greg
2020-05-14 16:15           ` Sean Christopherson
2020-05-14 16:20             ` Borislav Petkov
2020-05-14 19:29               ` Thomas Gleixner
2020-05-15  9:28               ` Jarkko Sakkinen
2020-05-15  9:42                 ` Borislav Petkov
2020-05-15 16:24                   ` Jarkko Sakkinen
2020-05-15  0:09             ` Jarkko Sakkinen
2020-05-15 19:54           ` Nathaniel McCallum
2020-05-16  9:58             ` Jarkko Sakkinen
2020-05-24 21:27           ` Pavel Machek
2020-05-26  8:16             ` David Laight
2020-04-26 17:03 ` Dr. Greg
2020-04-29 15:27 ` Jethro Beekman
2020-04-30  3:46   ` Jarkko Sakkinen
2020-04-30  7:19     ` Jethro Beekman
2020-04-30  8:23       ` Jarkko Sakkinen
2020-04-30 14:12         ` Jethro Beekman
2020-05-06 12:16           ` Jarkko Sakkinen
2020-05-06 16:39 ` Jordan Hand
2020-05-07 18:06   ` Dr. Greg
2020-05-08 16:16     ` Jordan Hand
2020-05-13 23:09   ` Jarkko Sakkinen
2020-05-06 21:42 ` Nathaniel McCallum
2020-05-06 22:14   ` Sean Christopherson [this message]
2020-05-07  5:02     ` Haitao Huang
2020-05-07 16:49       ` Nathaniel McCallum
2020-05-07 19:34         ` Sean Christopherson
2020-05-07 22:35           ` Haitao Huang
2020-05-08  0:25             ` Sean Christopherson
2020-05-28 11:15               ` Jarkko Sakkinen
2020-05-28 11:19                 ` Jarkko Sakkinen
2020-05-07 22:31         ` Haitao Huang
2020-05-13 22:14   ` Jarkko Sakkinen
2020-05-13 22:18     ` Jarkko Sakkinen
2020-05-14  6:31     ` Jethro Beekman
2020-05-14 19:30     ` Thomas Gleixner
2020-05-15  0:22       ` Jarkko Sakkinen
2020-05-08 19:08 ` Sean Christopherson
2020-05-14 19:05   ` Seth Moore
2020-05-15  0:23     ` Jarkko Sakkinen
2020-05-12 11:55 ` Hui, Chunyang
2020-05-12 16:51   ` Dr. Greg
2020-05-14 10:49   ` Jarkko Sakkinen
2020-05-16  8:53 ` [PATCH] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200506221422.GK3329@linux.intel.com \
    --to=sean.j.christopherson@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=bp@alien8.de \
    --cc=cedric.xing@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=haitao.huang@intel.com \
    --cc=jarkko.sakkinen@linux.intel.com \
    --cc=josh@joshtriplett.org \
    --cc=kai.huang@intel.com \
    --cc=kai.svahn@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sgx@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=nhorman@redhat.com \
    --cc=npmccallum@redhat.com \
    --cc=puiterwijk@redhat.com \
    --cc=rientjes@google.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).