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Message-ID: <70894c6b668dbfc3cc76c3b858c293b9f3a8446e.camel@kernel.org>
Subject: Re: [PATCH] x86/sgx: Free backing memory after faulting the enclave
 page
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Dave Hansen <dave.hansen@intel.com>,
        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
Date:   Thu, 04 Nov 2021 17:09:29 +0200
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References: <20211103232238.110557-1-jarkko@kernel.org>
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On Thu, 2021-11-04 at 17:04 +0200, Jarkko Sakkinen wrote:
> 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.

We have bookkeeping in place for this: encl->page_array.

/Jarkko