From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59299) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ctqf0-0004F2-54 for qemu-devel@nongnu.org; Fri, 31 Mar 2017 03:07:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ctqex-0004OX-0L for qemu-devel@nongnu.org; Fri, 31 Mar 2017 03:07:50 -0400 Received: from mga07.intel.com ([134.134.136.100]:43780) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ctqew-0004NO-Nl for qemu-devel@nongnu.org; Fri, 31 Mar 2017 03:07:46 -0400 From: "Zhang, Xiong Y" Date: Fri, 31 Mar 2017 07:07:37 +0000 Message-ID: <8082FF9BCB2B054996454E47167FF4EC1C494944@SHSMSX104.ccr.corp.intel.com> References: <1490869641-29873-1-git-send-email-xiong.y.zhang@intel.com> <20170330090148.16048141@t450s.home> <8082FF9BCB2B054996454E47167FF4EC1C4930B3@SHSMSX104.ccr.corp.intel.com> <20170330205511.28be6306@t450s.home> In-Reply-To: <20170330205511.28be6306@t450s.home> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] Revert "vfio/pci-quirks.c: Disable stolen memory for igd VFIO" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: "qemu-devel@nongnu.org" , "Zhang, Xiong Y" > On Fri, 31 Mar 2017 02:27:11 +0000 > "Zhang, Xiong Y" wrote: >=20 > > > On Thu, 30 Mar 2017 18:27:21 +0800 > > > Xiong Zhang wrote: > > > > > > > This reverts commit c2b2e158cc7b1cb431bd6039824ec13c3184a775. > > > > > > > > The original patch intend to prevent linux i915 driver from using > > > > stolen meory. But this patch breaks windows IGD driver loading on > > > > Gen9+, as IGD HW will use stolen memory on Gen9+, once windows IGD > > > > driver see zero size stolen memory, it will unload. > > > > Meanwhile stolen memory will be disabled in 915 when i915 run as > > > > a guest. > > > > > > Does this mean that legacy mode IGD assignment is not going to work > > > on Gen9+ with Windows? Will it continue to work with Gen8-? > > [Zhang, Xiong Y] I try to use the following qemu command to enable lega= cy > mode on SKyLake, but It seems the entry point of wins IGD driver isn't ca= lled(I > couldn't confirm this as I don't have the source code, but I didn't see a= ny IGD > driver info from windbg while I could see many info in upt mode), so driv= er > doesn't bind to IGD after win 8.1 boot up. > > #qemu-system-x86_64 -M pc -enable-kvm -smp 2 -m 2G -vga none > -nographic -cpu host -hda "$IMAGE" -device > vfio-pci,host=3D00:02.0,x-vga=3Dtrue,id=3Dhostdev0,bus=3Dpci.0,addr=3D0x2 > > Is this the right method to enable legacy mode ? >=20 > Yeah, that should do it. x-vga should not be necessary, but shouldn't > hurt IIRC. Any dmesg errors regarding the ROM? I think we have > trouble with the ROM if the host is booted in UEFI mode. [Zhang, Xiong Y] My host boot in legacy bios mode. After adding x-igd-gms i= n legacy mode, win 8.1 IGD driver could bind to IGD, and win 8.1 runs good.= =20 thanks >=20 > > > > > Please clarify Gen9+, is this Kaby Lake? > > [Zhang, Xiong Y] Gen 9+ is SkyLake and later. >=20 > Ok, then I cannot test since I only have access to BDW. We do have > users that might start complaining if this is a new change in the > Windows driver for SKL+. >=20 > > > I assume this patch is intended for QEMU 2.9, it's helpful to make th= at > > > explicit during the rc freeze. Thanks, > > [Zhang, Xiong Y] Yes, as the original patch has entered into Qemu 2.9 r= c1. So > this reverted patch should be entered into the later 2.9 rc. > > Sorry for the troubles. >=20 > Ok, no problem. Thanks, >=20 > Alex