From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= Subject: Re: [PATCH v2 4/4] xen: expose that grant table mappings update the IOMMU Date: Thu, 24 Apr 2014 09:43:22 +0200 Message-ID: <5358C09A.3020200@citrix.com> References: <1398240984-67266-1-git-send-email-roger.pau@citrix.com> <1398240984-67266-5-git-send-email-roger.pau@citrix.com> <5357AB53020000780000B4B7@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WdEJa-0001BE-Mm for xen-devel@lists.xenproject.org; Thu, 24 Apr 2014 07:43:26 +0000 In-Reply-To: <5357AB53020000780000B4B7@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: xen-devel@lists.xenproject.org, Keir Fraser List-Id: xen-devel@lists.xenproject.org On 23/04/14 12:00, Jan Beulich wrote: >>>> On 23.04.14 at 10:16, wrote: >> Add a new XENFEAT_hvm_gntmap_supports_iommu that is used to check >> whether the hypervisor properly updates the IOMMU on auto-translated >> guests when doing a grant table map/unmap operation. > > Considering Boris' pending introduction of a hypervisor capabilities > CPUID leaf, I wonder whether we shouldn't stop surfacing HVM-only > features via XENFEAT_* flags (which afaict originally were meant to > be a PV vehicle only anyway). I don't have a strong opinion on the best way to publish this feature, so if you prefer to do it using the new CPUID leaf, I will rework this patch (although I have to say using XENFEAT_* seems easier). Roger.