From: "Haitao Huang" <haitao.huang@linux.intel.com>
To: "Jarkko Sakkinen" <jarkko@kernel.org>,
dave.hansen@linux.intel.com, tglx@linutronix.de, bp@alien8.de,
luto@kernel.org, mingo@redhat.com, linux-sgx@vger.kernel.org,
x86@kernel.org, shuah@kernel.org,
linux-kselftest@vger.kernel.org,
"Reinette Chatre" <reinette.chatre@intel.com>
Cc: seanjc@google.com, kai.huang@intel.com, cathy.zhang@intel.com,
cedric.xing@intel.com, haitao.huang@intel.com,
mark.shanahan@intel.com, vijay.dhanraj@intel.com, hpa@zytor.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V4 14/31] x86/sgx: Support VA page allocation without reclaiming
Date: Fri, 15 Apr 2022 08:54:53 -0500 [thread overview]
Message-ID: <op.1kn59r1bwjvjmi@hhuan26-mobl1.mshome.net> (raw)
In-Reply-To: <767b99c5-f28e-4b8f-5147-6e1d290ca5c6@intel.com>
On Thu, 14 Apr 2022 11:30:34 -0500, Reinette Chatre
<reinette.chatre@intel.com> wrote:
> Hi Jarkko,
>
> On 4/14/2022 4:18 AM, Jarkko Sakkinen wrote:
>> On Wed, 2022-04-13 at 14:10 -0700, Reinette Chatre wrote:
>>> struct sgx_encl should be protected with the mutex
>>> sgx_encl->lock. One exception is sgx_encl->page_cnt that
>>> is incremented (in sgx_encl_grow()) when an enclave page
>>> is added to the enclave. The reason the mutex is not held
>>> is to allow the reclaimer to be called directly if there are
>>> no EPC pages (in support of a new VA page) available at the time.
>>>
>>> Incrementing sgx_encl->page_cnt without sgc_encl->lock held
>>> is currently (before SGX2) safe from concurrent updates because
>>> all paths in which sgx_encl_grow() is called occur before
>>> enclave initialization and are protected with an atomic
>>> operation on SGX_ENCL_IOCTL.
>>>
>>> SGX2 includes support for dynamically adding pages after
>>> enclave initialization where the protection of SGX_ENCL_IOCTL
>>> is not available.
>>>
>>> Make direct reclaim of EPC pages optional when new VA pages
>>> are added to the enclave. Essentially the existing "reclaim"
>>> flag used when regular EPC pages are added to an enclave
>>> becomes available to the caller when used to allocate VA pages
>>> instead of always being "true".
>>>
>>> When adding pages without invoking the reclaimer it is possible
>>> to do so with sgx_encl->lock held, gaining its protection against
>>> concurrent updates to sgx_encl->page_cnt after enclave
>>> initialization.
>>>
>>> No functional change.
>>>
>>> Reported-by: Haitao Huang <haitao.huang@intel.com>
>>> Tested-by: Haitao Huang <haitao.huang@intel.com>
>>> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
>>
>> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
>
> Thank you.
>
>>
>> Nit: I don't think tested-by is in the right patch here. Maybe
>> Haitao's tested-by should be moved into patch that actually adds
>> support for EAUG? Not something I would NAK this patch, just
>> wondering...
>
> Yes, that is a good point. While this is the bulk of the fix where
> the new API is introduced, the test is only applicable when this API
> is used and that is in "x86/sgx: Support adding of pages to an
> initialized enclave". I will move the "Tested-by" to that patch.
>
You can also add my Tested-by for patches adding the new IOCTLs.
Our team and I have tested EAUG on #PF, modifying types and permissions
with Intel SGX SDK/PSW.
Thanks
Haitao
next prev parent reply other threads:[~2022-04-15 13:55 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-13 21:10 [PATCH V4 00/31] x86/sgx and selftests/sgx: Support SGX2 Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 01/31] x86/sgx: Add short descriptions to ENCLS wrappers Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 02/31] x86/sgx: Add wrapper for SGX2 EMODPR function Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 03/31] x86/sgx: Add wrapper for SGX2 EMODT function Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 04/31] x86/sgx: Add wrapper for SGX2 EAUG function Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 05/31] x86/sgx: Support loading enclave page without VMA permissions check Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 06/31] x86/sgx: Export sgx_encl_ewb_cpumask() Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 07/31] x86/sgx: Rename sgx_encl_ewb_cpumask() as sgx_encl_cpumask() Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 08/31] x86/sgx: Move PTE zap code to new sgx_zap_enclave_ptes() Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 09/31] x86/sgx: Make sgx_ipi_cb() available internally Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 10/31] x86/sgx: Create utility to validate user provided offset and length Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 11/31] x86/sgx: Keep record of SGX page type Reinette Chatre
2022-04-14 11:12 ` Jarkko Sakkinen
2022-04-14 16:27 ` Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 12/31] x86/sgx: Export sgx_encl_{grow,shrink}() Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 13/31] x86/sgx: Export sgx_encl_page_alloc() Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 14/31] x86/sgx: Support VA page allocation without reclaiming Reinette Chatre
2022-04-14 11:18 ` Jarkko Sakkinen
2022-04-14 16:30 ` Reinette Chatre
2022-04-15 13:54 ` Haitao Huang [this message]
2022-04-15 15:22 ` Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 15/31] x86/sgx: Support restricting of enclave page permissions Reinette Chatre
2022-04-14 11:19 ` Jarkko Sakkinen
2022-04-14 11:19 ` Jarkko Sakkinen
2022-04-14 16:31 ` Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 16/31] x86/sgx: Support adding of pages to an initialized enclave Reinette Chatre
2022-04-14 11:20 ` Jarkko Sakkinen
2022-04-14 16:31 ` Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 17/31] x86/sgx: Tighten accessible memory range after enclave initialization Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 18/31] x86/sgx: Support modifying SGX page type Reinette Chatre
2022-04-14 11:11 ` Jarkko Sakkinen
2022-04-14 16:32 ` Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 19/31] x86/sgx: Support complete page removal Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 20/31] x86/sgx: Free up EPC pages directly to support large page ranges Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 21/31] Documentation/x86: Introduce enclave runtime management section Reinette Chatre
2022-04-14 11:21 ` Jarkko Sakkinen
2022-04-14 16:32 ` Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 22/31] selftests/sgx: Add test for EPCM permission changes Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 23/31] selftests/sgx: Add test for TCS page " Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 24/31] selftests/sgx: Test two different SGX2 EAUG flows Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 25/31] selftests/sgx: Introduce dynamic entry point Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 26/31] selftests/sgx: Introduce TCS initialization enclave operation Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 27/31] selftests/sgx: Test complete changing of page type flow Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 28/31] selftests/sgx: Test faulty enclave behavior Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 29/31] selftests/sgx: Test invalid access to removed enclave page Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 30/31] selftests/sgx: Test reclaiming of untouched page Reinette Chatre
2022-04-13 21:10 ` [PATCH V4 31/31] selftests/sgx: Page removal stress test Reinette Chatre
2022-04-14 11:25 ` [PATCH V4 00/31] x86/sgx and selftests/sgx: Support SGX2 Jarkko Sakkinen
2022-04-14 16:34 ` Reinette Chatre
2022-04-14 16:55 ` Jarkko Sakkinen
2022-04-14 18:35 ` Dhanraj, Vijay
2022-04-17 14:58 ` Jarkko Sakkinen
2022-04-21 23:46 ` Dhanraj, Vijay
2022-04-22 3:29 ` Reinette Chatre
2022-04-22 9:16 ` Jarkko Sakkinen
2022-04-22 13:17 ` Jarkko Sakkinen
2022-04-25 20:17 ` Dhanraj, Vijay
2022-04-25 23:56 ` Reinette Chatre
2022-04-26 4:10 ` Jarkko Sakkinen
2022-04-22 9:14 ` Jarkko Sakkinen
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