From: Dave Hansen <dave.hansen@intel.com>
To: Jarkko Sakkinen <jarkko@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Jethro Beekman <jethro@fortanix.com>,
Sean Christopherson <seanjc@google.com>
Cc: reinette.chatre@intel.com, tony.luck@intel.com,
nathaniel@profian.com, stable@vger.kernel.org,
Borislav Petkov <bp@suse.de>,
linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/sgx: Free backing memory after faulting the enclave page
Date: Thu, 4 Nov 2021 08:13:39 -0700 [thread overview]
Message-ID: <d2191571-30a5-c2aa-e8ed-0a380e9daeac@intel.com> (raw)
In-Reply-To: <e88d6d580354aadaa8eaa5ee6fa703f021786afb.camel@kernel.org>
On 11/4/21 8:04 AM, Jarkko Sakkinen wrote:
>> Do we also need to deal with truncating the PCMD? (For those watching
>> along at home, there are two things SGX swaps to RAM: the actual page
>> data and also some metadata that ensures page integrity and helps
>> prevent things like rolling back to old versions of swapped pages)
> Yes.
>
> This can be achieved by iterating through all of the enclave pages,
> which share the same shmem page for storing their PCMD's, as the one
> being faulted back. If none of those pages is swapped, the PCMD page can
> safely truncated.
I was thinking we could just read the page. If it's all 0's, truncate it.
next prev parent reply other threads:[~2021-11-04 15:13 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-03 23:22 [PATCH] x86/sgx: Free backing memory after faulting the enclave page Jarkko Sakkinen
2021-11-04 13:50 ` Dave Hansen
2021-11-04 15:04 ` Jarkko Sakkinen
2021-11-04 15:09 ` Jarkko Sakkinen
2021-11-04 15:13 ` Dave Hansen [this message]
2021-11-04 15:25 ` Jarkko Sakkinen
2021-11-04 15:29 ` Dave Hansen
2021-11-07 19:42 ` Jarkko Sakkinen
2021-11-07 19:51 ` Dave Hansen
2021-11-07 22:28 ` Jarkko Sakkinen
2021-11-08 6:34 ` Dave Hansen
2021-11-08 20:07 ` Jarkko Sakkinen
2021-11-04 22:38 ` Dave Hansen
2021-11-07 18:06 ` Jarkko Sakkinen
2021-11-07 19:06 ` Dave Hansen
2021-11-07 19:45 ` Jarkko Sakkinen
2021-11-07 19:58 ` Dave Hansen
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