From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suravee Suthikulpanit Subject: Re: AMD Ryzen KVM/NPT/IOMMU issue Date: Thu, 29 Jun 2017 01:53:57 +0700 Message-ID: <5d2ea709-8f90-bfaa-975d-48aed39e75ad@amd.com> References: <575f8fbc-0fdc-f336-e3da-53f27da4b2e1@markju.com> <20170505112706.7785948c@t450s.home> <545f19a3-4923-cdec-4ce9-2a4155a04f6a@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Steven Walter Cc: "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Matthias Ehrenfeuchter , John.Bridgman-5C7GfCeVMHo@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Paolo Bonzini List-Id: iommu@lists.linux-foundation.org On 6/29/17 00:26, Steven Walter wrote: >> So, I'm trying to reproduce this issue on the Ryzen system w/ the following >> setup: >> >> * Host kernel v4.11 (with this patch https://lkml.org/lkml/2017/6/23/295) >> >> * guest VM RHEL7.3 >> >> * guest graphic driver = radeon >> >> * qemu-system-x86_64 --version >> QEMU emulator version 2.9.50 (v2.9.0-1659-g577caa2-dirty) >> >> * kvm-amd npt=1 >> >> * dGPU is 08:00.0 VGA compatible controller: Advanced Micro Devices, Inc. >> [AMD/ATI] Tobago PRO [Radeon R7 360 / R9 360 OEM] (rev 81) >> >> * qemu-system-x86_64 -smp 4 -enable-kvm -M q35 -m 4096 -cpu host -bios >> /usr/share/qemu/bios.bin -device >> ioh3420,bus=pcie.0,addr=1c.0,multifunction=on,port=1,chassis=1,id=root.1 >> -drive file=/sandbox/vm-images/rhel7.3.qcow2,if=virtio,id=disk0 -net none >> -vga none -nodefaults -device >> vfio-pci,host=08:00.0,x-vga=on,addr=0.0,multifunction=on,bus=root.1,romfile=/sandbox/vm-images/vbios.rom >> -usb -device usb-host,hostbus=3,hostport=1 -device >> usb-host,hostbus=3,hostport=3 -device vfio-pci,host=0000:08:00.1 -device >> vfio-pci,host=0000:09:00.0 >> >> With this setup, I am able to pass-through the dGPU and run the following >> test: >> * Starting up the guest w/ full GNOME GUI on the attached monitor. >> * glxgears (running @ 60 FPS) >> * Playing 1080p HD video on Youtube >> >> I am not noticing issues here. What kind of test are you running in the >> guest VM? > Try running the open source game "torcs" inside the VM. I think > you'll find that there's a very noticeable performance different > between npt=1 and npt=0 Hm.. actually torcs seems to be running fine w/ npt=1 setup. Although I think my driving skill is ~20% worse :( S