From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCHv1 1/3] x86/ept: remove unnecessary sync after resolving misconfigured entries Date: Fri, 6 Nov 2015 18:29:10 +0000 Message-ID: <563CF176.8020105@citrix.com> References: <1446831437-5897-1-git-send-email-david.vrabel@citrix.com> <1446831437-5897-2-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZullL-0005vd-OJ for xen-devel@lists.xenproject.org; Fri, 06 Nov 2015 18:29:23 +0000 In-Reply-To: <1446831437-5897-2-git-send-email-david.vrabel@citrix.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: David Vrabel , xen-devel@lists.xenproject.org Cc: Kevin Tian , Jan Beulich , Jun Nakajima List-Id: xen-devel@lists.xenproject.org On 06/11/15 17:37, David Vrabel wrote: > When using EPT, type changes are done with the following steps: > > 1. Set entry as invalid (misconfigured) by settings a reserved memory > type. > > 2. Flush all EPT and combined translations (ept_sync_domain()). > > 3. Fixup misconfigured entries as required (on EPT_MISCONFIG vmexits or > when explicitly setting an entry. > > Since resolve_misconfig() only updates entries that were misconfigured, > there is no need to invalidate any translations since the hardware > does not cache misconfigured translations (vol 3, section 28.3.2). > > Remove the unnecessary (and very expensive) ept_sync_domain() calls). > > Signed-off-by: David Vrabel Reviewed-by: Andrew Cooper