From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel De Graaf Subject: Re: [PATCH 10/20] xsm: Add IS_PRIV checks to dummy XSM module Date: Tue, 11 Sep 2012 09:24:21 -0400 Message-ID: <504F3B85.3010103@tycho.nsa.gov> References: <1347306553-20980-1-git-send-email-dgdegra@tycho.nsa.gov> <1347306553-20980-11-git-send-email-dgdegra@tycho.nsa.gov> <504F0811020000780009A6D5@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <504F0811020000780009A6D5@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Keir Fraser , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 09/11/2012 03:44 AM, Jan Beulich wrote: >>>> On 10.09.12 at 21:49, Daniel De Graaf wrote: >> --- a/xen/include/xsm/xsm.h >> +++ b/xen/include/xsm/xsm.h >> @@ -21,11 +21,7 @@ >> typedef void xsm_op_t; >> DEFINE_XEN_GUEST_HANDLE(xsm_op_t); >> >> -#ifdef XSM_ENABLE >> - #define xsm_call(fn) xsm_ops->fn >> -#else >> - #define xsm_call(fn) 0 >> -#endif >> +#define xsm_call(fn) xsm_ops->fn > > So am I getting it right that with XSM disabled this now adds an > indirect call in almost every hypercall? I'm not really in favor of > that, particularly not if that affects hot path ones like the MMU > operations. > > Jan > No. With XSM disabled, this part of the header file is not used; instead, xsm/dummy.h is included with XSM_DEFAULT set up to generate inline functions. So there should be no slowdown if XSM is disabled. -- Daniel De Graaf National Security Agency