From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55297) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gEbQr-00031e-R8 for qemu-devel@nongnu.org; Mon, 22 Oct 2018 10:43:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gEbQn-0002vs-Qq for qemu-devel@nongnu.org; Mon, 22 Oct 2018 10:43:49 -0400 Received: from outprodmail01.cc.columbia.edu ([128.59.72.39]:37222) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gEbQn-0002v0-IO for qemu-devel@nongnu.org; Mon, 22 Oct 2018 10:43:45 -0400 Received: from hazelnut (hazelnut.cc.columbia.edu [128.59.213.250]) by outprodmail01.cc.columbia.edu (8.14.4/8.14.4) with ESMTP id w9MEhEik023603 for ; Mon, 22 Oct 2018 10:43:44 -0400 Received: from hazelnut (localhost.localdomain [127.0.0.1]) by hazelnut (Postfix) with ESMTP id 983336D for ; Mon, 22 Oct 2018 10:43:44 -0400 (EDT) Received: from sendprodmail04.cc.columbia.edu (sendprodmail04.cc.columbia.edu [128.59.72.16]) by hazelnut (Postfix) with ESMTP id 78C7080 for ; Mon, 22 Oct 2018 10:43:44 -0400 (EDT) Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by sendprodmail04.cc.columbia.edu (8.14.4/8.14.4) with ESMTP id w9MEhhE9035269 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 22 Oct 2018 10:43:44 -0400 Received: by mail-ed1-f71.google.com with SMTP id h24-v6so24732797eda.10 for ; Mon, 22 Oct 2018 07:43:44 -0700 (PDT) Received: from mail-wm1-f42.google.com (mail-wm1-f42.google.com. [209.85.128.42]) by smtp.gmail.com with ESMTPSA id gy12-v6sm6820379ejb.32.2018.10.22.07.43.41 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Oct 2018 07:43:41 -0700 (PDT) Received: by mail-wm1-f42.google.com with SMTP id y144-v6so10611176wmd.4 for ; Mon, 22 Oct 2018 07:43:41 -0700 (PDT) MIME-Version: 1.0 References: <20181022092710.GH32717@xz-x1> In-Reply-To: <20181022092710.GH32717@xz-x1> From: Jintack Lim Date: Mon, 22 Oct 2018 10:43:32 -0400 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] Virtual IOMMU is working for Windows VM? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: QEMU Devel Mailing List , lprosek@redhat.com On Mon, Oct 22, 2018 at 5:27 AM Peter Xu wrote: > > On Mon, Oct 22, 2018 at 12:22:02AM -0400, Jintack Lim wrote: > > Hi, > > > > I wonder if vIOMMU is working for Windows VM? > > > > I tried it with v2.11.0, but it didn't seem to work. I assume that seaBIOS > > sets IOMMU on by default as is the case when I launched a Linux VM. But I > > might be missing something. Can somebody shed some light on it? > > Hi, Jintack, > Thanks Peter, > I think at least the latest QEMU should work for Windows, but I don't > really run Windows that frequently. > > What is the error you've encountered? Have you tried the latest QEMU, > or switching Windows versions to try? I ran Windows commands in Windows Powershell like below. Well, I guess this is not the best way to check IOMMU presence, but couldn't find a better way to do it. $ (Get-VMHost).IovSupport false $ (Get-VMHost).IovSupportReasons The chipset on the system does not do DMA remapping, ... I just tried QEMU v3.0.0, but I see the same symptom. I'm using Windows server 2016. Unfortunately, trying another Windows version would be hard for me at this point. I just wonder if there's way to check if Vt-d is on in SeaBIOS? > > What I can remember about Windows is that Ladi had fixed a bug for > windows-only (8991c460be, "intel_iommu: relax iq tail check on > VTD_GCMD_QIE enable", 2017-07-03) but it should be even in 2.10 so I > guess it's not the problem you've encountered. I'm CCing Ladi, just in case he has some idea :) Thanks, Jintack > > Regards, > > -- > Peter Xu >