On Fri, 31 Mar 2017 02:27:11 +0000 "Zhang, Xiong Y" <xiong.y.zh...@intel.com> wrote:
> > On Thu, 30 Mar 2017 18:27:21 +0800 > > Xiong Zhang <xiong.y.zh...@intel.com> 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 legacy > mode on SKyLake, but It seems the entry point of wins IGD driver isn't > called(I couldn't confirm this as I don't have the source code, but I didn't > see any IGD driver info from windbg while I could see many info in upt mode), > so driver 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=00:02.0,x-vga=true,id=hostdev0,bus=pci.0,addr=0x2 > Is this the right method to enable legacy mode ? 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. > > > Please clarify Gen9+, is this Kaby Lake? > [Zhang, Xiong Y] Gen 9+ is SkyLake and later. 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+. > > I assume this patch is intended for QEMU 2.9, it's helpful to make that > > explicit during the rc freeze. Thanks, > [Zhang, Xiong Y] Yes, as the original patch has entered into Qemu 2.9 rc1. So > this reverted patch should be entered into the later 2.9 rc. > Sorry for the troubles. Ok, no problem. Thanks, Alex
