From: Jarkko Sakkinen <jarkko.sakkinen@iki.fi>
To: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/2] x86/sgx: Limit EPC overcommit
Date: Sat, 15 Jan 2022 21:02:05 +0200 [thread overview]
Message-ID: <YeMaLTtcx9t0+HGG@iki.fi> (raw)
In-Reply-To: <YeMZJ7gZi8JzTYYd@iki.fi>
On Sat, Jan 15, 2022 at 08:57:44PM +0200, Jarkko Sakkinen wrote:
> On Fri, Jan 07, 2022 at 10:16:15AM -0800, Kristen Carlson Accardi wrote:
> > SGX currently allows EPC pages to be overcommitted. If the system is
> > out of enclave memory, EPC pages are swapped to normal RAM via
> > a per enclave shared memory area. This shared memory is not charged
> > to the enclave or the task mapping it, making it hard to account
> > for using normal methods. Since SGX will allow EPC pages to be
> > overcommitted without limits, enclaves can consume system memory
> > for these backing pages without limits.
> >
> > In order to prevent this, set a cap on the amount of overcommit SGX
> > allows. Whenever a backing page is requested by an enclave, track
> > the total amount of shared memory pages used across all enclaves and
> > return an error if the overcommit limit has been reached. This will
> > restrict the total amount of backing pages that all enclaves can
> > consume to a maximum amount, and prevent enclaves from consuming
> > all the system RAM for backing pages.
> >
> > The overcommit percentage has a value of 150, which limits shared
> > memory page consumption to 1.5x the number of EPC pages in the system.
> >
> > Changes from v1
> > ----------------
> > * removed module parameter and disable boolean
> > * increased over commit percentage to 150% from 100%
> >
> > Kristen Carlson Accardi (2):
> > x86/sgx: Add accounting for tracking overcommit
> > x86/sgx: account backing pages
> >
> > arch/x86/kernel/cpu/sgx/encl.c | 76 ++++++++++++++++++++++++++++++++--
> > arch/x86/kernel/cpu/sgx/encl.h | 6 ++-
> > arch/x86/kernel/cpu/sgx/main.c | 52 +++++++++++++++++++++--
> > arch/x86/kernel/cpu/sgx/sgx.h | 2 +
> > 4 files changed, 128 insertions(+), 8 deletions(-)
> >
> > --
> > 2.20.1
> >
>
> I've tested also these. Looking at the feedback, there's
> nothing game changing, so you could add for the next
> version:
>
> Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
The test environment was a VM running my desktop [*] and I just
run many instances of kselftest as a test case.
[*] i5-9600KF CPU
/Jarkko
prev parent reply other threads:[~2022-01-15 19:02 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-07 18:16 [PATCH v2 0/2] x86/sgx: Limit EPC overcommit Kristen Carlson Accardi
2022-01-07 18:16 ` [PATCH v2 1/2] x86/sgx: Add accounting for tracking overcommit Kristen Carlson Accardi
2022-01-07 18:46 ` Dave Hansen
2022-01-07 19:16 ` Kristen Carlson Accardi
2022-01-11 14:20 ` Haitao Huang
2022-01-11 15:43 ` Dave Hansen
2022-01-11 16:33 ` Haitao Huang
2022-01-11 17:39 ` Dave Hansen
2022-01-14 17:45 ` Kristen Carlson Accardi
2022-01-08 15:59 ` Jarkko Sakkinen
2022-01-14 17:47 ` Kristen Carlson Accardi
2022-01-07 18:16 ` [PATCH v2 2/2] x86/sgx: account backing pages Kristen Carlson Accardi
2022-01-08 16:05 ` Jarkko Sakkinen
2022-01-14 17:51 ` Kristen Carlson Accardi
2022-01-14 17:55 ` Dave Hansen
2022-01-14 23:57 ` Jarkko Sakkinen
2022-01-15 0:16 ` Dave Hansen
2022-01-15 0:56 ` Jarkko Sakkinen
2022-01-14 23:52 ` Jarkko Sakkinen
2022-01-14 23:55 ` Dave Hansen
2022-01-15 0:58 ` Jarkko Sakkinen
2022-01-15 18:57 ` [PATCH v2 0/2] x86/sgx: Limit EPC overcommit Jarkko Sakkinen
2022-01-15 19:02 ` Jarkko Sakkinen [this message]
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=YeMaLTtcx9t0+HGG@iki.fi \
--to=jarkko.sakkinen@iki.fi \
--cc=kristen@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sgx@vger.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).