From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: Re: [PATCH v17 07/23] x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit Date: Sun, 18 Nov 2018 10:38:16 +0200 Message-ID: <20181118083816.GN5897@linux.intel.com> References: <20181116010412.23967-1-jarkko.sakkinen@linux.intel.com> <20181116010412.23967-8-jarkko.sakkinen@linux.intel.com> <38993cf5-039a-d582-1759-876cb948c582@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <38993cf5-039a-d582-1759-876cb948c582@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Dave Hansen Cc: x86@kernel.org, platform-driver-x86@vger.kernel.org, linux-sgx@vger.kernel.org, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@linux.intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, mark.shanahan@intel.com, luto@amacapital.net, Dave Hansen , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" List-Id: platform-driver-x86.vger.kernel.org On Fri, Nov 16, 2018 at 03:33:35PM -0800, Dave Hansen wrote: > On 11/15/18 5:01 PM, Jarkko Sakkinen wrote: > > The SGX bit is set in the #PF error code if and only if the fault is > > detected by the Enclave Page Cache Map (EPCM), a hardware-managed > > table that enforces the paging permissions defined by the enclave, > > e.g. to prevent the kernel from changing the permissions of an > > enclave's page(s). > > This should probably also mention that, despite being a page fault, > X86_PF_SGX has nothing to do with paging itself. A valid point. /Jarkko