From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51484) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b58av-0000c9-FL for qemu-devel@nongnu.org; Tue, 24 May 2016 05:25:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b58ar-0005ac-4Z for qemu-devel@nongnu.org; Tue, 24 May 2016 05:25:44 -0400 Received: from goliath.siemens.de ([192.35.17.28]:53026) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b58aq-0005a1-Qa for qemu-devel@nongnu.org; Tue, 24 May 2016 05:25:41 -0400 References: <1463847590-22782-1-git-send-email-bd.aviv@gmail.com> <1463847590-22782-2-git-send-email-bd.aviv@gmail.com> <57440D4C.2070303@redhat.com> From: Jan Kiszka Message-ID: <57441E0F.9020000@siemens.com> Date: Tue, 24 May 2016 11:25:35 +0200 MIME-Version: 1.0 In-Reply-To: <57440D4C.2070303@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v3 1/3] IOMMU: add VTD_CAP_CM to vIOMMU capability exposed to guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang , "Aviv B.D" , qemu-devel@nongnu.org Cc: Alex Williamson , Peter Xu , "Michael S. Tsirkin" On 2016-05-24 10:14, Jason Wang wrote: > On 2016=E5=B9=B405=E6=9C=8822=E6=97=A5 00:19, Aviv B.D wrote: >> From: "Aviv Ben-David" >> >> This flag tells the guest to invalidate tlb cache also after unmap >> operations. >> >> Signed-off-by: Aviv Ben-David >> --- >=20 > Is this a guest visible behavior? If yes, shouldn't we cache > translation fault conditions in IOTLB? It is guest visible, and this first of all means, besides requiring to be optional, that it definitely needs to be off for compat systems. Or it stays off by default. Jan --=20 Siemens AG, Corporate Technology, CT RDA ITP SES-DE Corporate Competence Center Embedded Linux