From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Subject: Re: [PATCH v13 09/13] x86/sgx: Enclave Page Cache (EPC) memory
 manager
Date: Tue, 28 Aug 2018 11:35:40 +0300
Message-ID: <20180828083540.GH15508@linux.intel.com>
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To: Dave Hansen <dave.hansen@intel.com>
Cc: x86@kernel.org, platform-driver-x86@vger.kernel.org, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, linux-sgx@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, Suresh Siddha <suresh.b.siddha@intel.com>, Serge Ayoun <serge.ayoun@intel.com>, "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <linux-kernel@vger.kernel.org>
List-Id: platform-driver-x86.vger.kernel.org

On Mon, Aug 27, 2018 at 02:15:34PM -0700, Dave Hansen wrote:
> On 08/27/2018 11:53 AM, Jarkko Sakkinen wrote:
> > +struct sgx_epc_page_ops {
> > +	bool (*get)(struct sgx_epc_page *epc_page);
> > +	void (*put)(struct sgx_epc_page *epc_page);
> > +	bool (*reclaim)(struct sgx_epc_page *epc_page);
> > +	void (*block)(struct sgx_epc_page *epc_page);
> > +	void (*write)(struct sgx_epc_page *epc_page);
> > +};
> 
> Why do we need a fancy, slow (retpoline'd) set of function pointers when
> we only have one user of these (the SGX driver)?

KVM has its own implementation for these operations.

/Jarkko