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w4rum

Member

Registered: 2017-01-14

Posts: 7

[SOLVED] Win10 on QEMU crashes with Hyper-V enlightenments enabled

First of all, I wasn't sure which subforum to post this in. Since I'm using
the VM to play video games, I figured this one could fit. Please tell me if
there's a better place for this.

Problem:
When enabling Hyper-V enlightenments by passing the required command-line
parameters as described in this blog post, the VM either doesn't boot or crashes
after a few minutes.

My old Windows 10 installation that I set up and used for a couple of months
before I enabled the enlightenments doesn't get past the "TianoCore" screen,
with the spinner freezing very briefly multiple times before stopping
completely. The system then reboots into Windows 10's recovery mode and
displays a "SYSTEM_THREAD_EXCEPTION_NOT_HANDLED"-BSOD before rebooting
and starting the cycle anew.

I've set up another installation with the enlightenments enabled during set up.
This installation makes it to the desktop but will crash without warning after
a couple of minutes, suddenly cutting video output and then booting into
recovery mode just like the other installation.

I haven't found any reports of this elsewhere and hope someone can make sense of
this here. Maybe I'm just missing something very obvious. Thanks in advance!

Hardware:
CPU: Intel i5-6600
GPU: AMD Radeon R9-280x (passed through)
MB: ASRock H170 PRO4/D3

Configuration files:
Kernel parameters:

cryptdevice=... root=... quiet rw intel_iommu=on

I'm usually using CK's skylake-optimized kernel but the problem occurs with the generic
standard kernel as well.

VFIO-PCI config (/etc/modprobe.d/vfio.conf):

options vfio-pci ids=1002:6798,1002:aaa0

Mkinitcpio:

MODULES="intel_agp i915 vfio vfio_iommu_type1 vfio_pci vfio_virqfd"
HOOKS="base udev autodetect modconf block keyboard encrypt lvm2 filesystems fsck"

QEMU start-script:

#!/bin/bash

# QEMU name and PID
OPTS="-name windows-10-pro"
OPTS="$OPTS -pidfile /tmp/windows-10-pro.pid"

# Processor
OPTS="$OPTS -cpu host,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time"
OPTS="$OPTS -smp cores=4,threads=1"
OPTS="$OPTS -enable-kvm"

# Machine
OPTS="$OPTS -machine type=q35,accel=kvm"

# Memory
OPTS="$OPTS -m 8G"
OPTS="$OPTS -mem-path /dev/hugepages"
OPTS="$OPTS -mem-prealloc"
OPTS="$OPTS -balloon none"

# Hardware clock
OPTS="$OPTS -rtc clock=host,base=utc"

# Sound hardware
export QEMU_PA_SAMPLES=128
export QEMU_AUDIO_DRV=pa
export QEMU_PA_SERVER="/tmp/pulseaudio.sock"
OPTS="$OPTS -soundhw ac97"

# Turn off QEMU-window video
OPTS="$OPTS -vga none"

# Graphic card passthrough (AMD Radeon R9 280x)
OPTS="$OPTS -device vfio-pci,host=01:00.0,multifunction=on"
OPTS="$OPTS -device vfio-pci,host=01:00.1"

# Emulate another USB driver chip instead
OPTS="$OPTS -M q35"

# USB 3.0 passthrough
OPTS="$OPTS -usb"
OPTS="$OPTS -usbdevice host:045e:028e"

# Boot priority
OPTS="$OPTS -boot order=c"

# OVMF
sudo cp /usr/share/ovmf/ovmf_vars_x64.bin /tmp/my_vars.bin
OPTS="$OPTS -drive if=pflash,format=raw,readonly,file=/usr/share/ovmf/ovmf_code_x64.bin"
OPTS="$OPTS -drive if=pflash,format=raw,file=/tmp/my_vars.bin"

# System drive
OPTS="$OPTS -drive id=disk0,if=none,cache=none,format=raw,file=/mnt/ssd-linux/winvm/img"
OPTS="$OPTS -device driver=virtio-scsi-pci,id=scsi0"
OPTS="$OPTS -device scsi-hd,drive=disk0"

# Network
OPTS="$OPTS -net nic -net bridge,br=br0"

sudo sh -c "echo 4500 > /proc/sys/vm/nr_hugepages"
sudo qemu-system-x86_64 $OPTS
sudo sh -c "echo 0 > /proc/sys/vm/nr_hugepages"

Last edited by w4rum (2018-01-22 12:00:10)

w4rum

Member

Registered: 2017-01-14

Posts: 7

Re: [SOLVED] Win10 on QEMU crashes with Hyper-V enlightenments enabled

Alright, setting kvm=off and adding the hv_vendor_id parameter fixed the problem on both installations.

OPTS="$OPTS -cpu host,kvm=off,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time,hv_vendor_id=whatever"

Although I don't quite get why that is, given that I've only read Nvidia GPU users experiencing this kind of problem (see this reddit post).

Unfortunately, I'm also not seeing any noticable CPU performance improvements. Nevertheless, I'll mark the thread as solved.

Last edited by w4rum (2018-01-22 12:01:07)