Hey there,
I’m having one hell of a time with my Windows 10 VM. Here’s my predicament - I recently bought an ROG Zephyrus G15. Specs are a Ryzen 7 4800HS, 16GB RAM, and a GTX 1660Ti. I’m using the iGPU for my host and passing through the 1660Ti, using a dummy display and Looking Glass to view it. Arch is the host OS.
The intention of the VM is exclusively to play EAC games such as Fortnite and Hunt: Showdown which can’t be run on Linux. Typical operation is indistinguisable, but I am having noticeable issues when firing up a game.
For example, using CS:GO as a main benchmark, I average about 170-180 FPS running baremetal on Linux. On Windows baremetal, it’s about the same (within 10 FPS). However, on the VM, I’m getting about 50-60. Another is example is League of Legends. Using Wine in Linux, I average around 140 FPS, with 10-20 FPS difference on baremetal Windows. On the VM, I get around 60FPS, sometimes peaking to 70. As I know Fortnite is a pretty demanding game for the hardware I’m using, I haven’t yet installed it on the VM.
Now I know Looking Glass and using a VM to game isn’t perfect, and I should expect some performance loss, but I feel like getting an FPS loss of over 50% isn’t normal.
I have tried with and without hugepages, and have tried using 12 vcpus, and then also tried only 8, as I read somewhere that only running the VM on cores which are all on the same CCX might help. I really think this is some weird CPU or Ryzen-specific issue, but I’m open to any suggestions or tweaks that you think might help.
Here’s my libvirt XML as well. If there’s any other important info I failed to mention please just let me know and I’ll provide it!
<domain xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0" type="kvm">
<name>win10</name>
<uuid>f8804fe6-222e-4f27-93da-ed0674bd86f3</uuid>
<metadata>
<libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
<libosinfo:os id="http://microsoft.com/win/10"/>
</libosinfo:libosinfo>
</metadata>
<memory unit="KiB">8388608</memory>
<currentMemory unit="KiB">8388608</currentMemory>
<vcpu placement="static" cpuset="8-15">8</vcpu>
<iothreads>1</iothreads>
<cputune>
<vcpupin vcpu="0" cpuset="8"/>
<vcpupin vcpu="1" cpuset="9"/>
<vcpupin vcpu="2" cpuset="10"/>
<vcpupin vcpu="3" cpuset="11"/>
<vcpupin vcpu="4" cpuset="12"/>
<vcpupin vcpu="5" cpuset="13"/>
<vcpupin vcpu="6" cpuset="14"/>
<vcpupin vcpu="7" cpuset="15"/>
<emulatorpin cpuset="0-3"/>
<iothreadpin iothread="1" cpuset="4-7"/>
</cputune>
<os>
<type arch="x86_64" machine="pc-q35-5.2">hvm</type>
<loader readonly="yes" type="pflash">/usr/share/edk2-ovmf/x64/OVMF_CODE.fd</loader>
<nvram>/var/lib/libvirt/qemu/nvram/win10_VARS.fd</nvram>
<boot dev="hd"/>
<bootmenu enable="no"/>
</os>
<features>
<acpi/>
<apic/>
<hyperv>
<relaxed state="on"/>
<vapic state="on"/>
<spinlocks state="on" retries="8191"/>
<vpindex state="on"/>
<runtime state="on"/>
<synic state="on"/>
<stimer state="on"/>
<reset state="on"/>
<vendor_id state="on" value="GAMINGVM"/>
<frequencies state="on"/>
</hyperv>
<kvm>
<hidden state="on"/>
</kvm>
<vmport state="off"/>
</features>
<cpu mode="host-passthrough" check="none" migratable="off">
<topology sockets="1" dies="1" cores="4" threads="2"/>
<cache mode="passthrough"/>
<feature policy="require" name="topoext"/>
<feature policy="require" name="svm"/>
<feature policy="require" name="apic"/>
<feature policy="require" name="hypervisor"/>
<feature policy="require" name="invtsc"/>
<feature policy="disable" name="amd-stibp"/>
</cpu>
<clock offset="localtime">
<timer name="rtc" tickpolicy="catchup"/>
<timer name="pit" tickpolicy="delay"/>
<timer name="hpet" present="no"/>
<timer name="kvmclock" present="no"/>
<timer name="hypervclock" present="yes"/>
<timer name="tsc" present="yes" mode="native"/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>destroy</on_crash>
<pm>
<suspend-to-mem enabled="no"/>
<suspend-to-disk enabled="no"/>
</pm>
<devices>
<emulator>/usr/bin/qemu-system-x86_64</emulator>
<disk type="file" device="disk">
<driver name="qemu" type="qcow2" cache="writeback" discard="unmap"/>
<source file="/var/lib/libvirt/images/win10.qcow2"/>
<target dev="vda" bus="virtio"/>
<address type="pci" domain="0x0000" bus="0x03" slot="0x00" function="0x0"/>
</disk>
<controller type="usb" index="0" model="qemu-xhci" ports="15">
<address type="pci" domain="0x0000" bus="0x02" slot="0x00" function="0x0"/>
</controller>
<controller type="sata" index="0">
<address type="pci" domain="0x0000" bus="0x00" slot="0x1f" function="0x2"/>
</controller>
<controller type="pci" index="0" model="pcie-root"/>
<controller type="pci" index="1" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="1" port="0x10"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x0" multifunction="on"/>
</controller>
<controller type="pci" index="2" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="2" port="0x11"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x1"/>
</controller>
<controller type="pci" index="3" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="3" port="0x12"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x2"/>
</controller>
<controller type="pci" index="4" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="4" port="0x13"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x3"/>
</controller>
<controller type="pci" index="5" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="5" port="0x14"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x4"/>
</controller>
<controller type="pci" index="6" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="6" port="0x15"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x5"/>
</controller>
<controller type="pci" index="7" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="7" port="0x16"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x6"/>
</controller>
<controller type="pci" index="8" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="8" port="0x17"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x7"/>
</controller>
<controller type="pci" index="9" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="9" port="0x18"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0" multifunction="on"/>
</controller>
<controller type="pci" index="10" model="pcie-to-pci-bridge">
<model name="pcie-pci-bridge"/>
<address type="pci" domain="0x0000" bus="0x09" slot="0x00" function="0x0"/>
</controller>
<controller type="pci" index="11" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="11" port="0x19"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x1"/>
</controller>
<controller type="pci" index="12" model="pcie-root-port">
<model name="pcie-root-port"/>
<target chassis="12" port="0x1a"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x2"/>
</controller>
<interface type="network">
<mac address="52:54:00:fa:e3:93"/>
<source network="default"/>
<model type="virtio"/>
<address type="pci" domain="0x0000" bus="0x01" slot="0x00" function="0x0"/>
</interface>
<input type="mouse" bus="ps2"/>
<input type="keyboard" bus="ps2"/>
<hostdev mode="subsystem" type="pci" managed="yes">
<source>
<address domain="0x0000" bus="0x01" slot="0x00" function="0x0"/>
</source>
<address type="pci" domain="0x0000" bus="0x05" slot="0x00" function="0x0"/>
</hostdev>
<hostdev mode="subsystem" type="pci" managed="yes">
<source>
<address domain="0x0000" bus="0x01" slot="0x00" function="0x1"/>
</source>
<address type="pci" domain="0x0000" bus="0x06" slot="0x00" function="0x0"/>
</hostdev>
<hostdev mode="subsystem" type="pci" managed="yes">
<source>
<address domain="0x0000" bus="0x01" slot="0x00" function="0x2"/>
</source>
<address type="pci" domain="0x0000" bus="0x07" slot="0x00" function="0x0"/>
</hostdev>
<hostdev mode="subsystem" type="pci" managed="yes">
<source>
<address domain="0x0000" bus="0x01" slot="0x00" function="0x3"/>
</source>
<address type="pci" domain="0x0000" bus="0x08" slot="0x00" function="0x0"/>
</hostdev>
<memballoon model="virtio">
<address type="pci" domain="0x0000" bus="0x04" slot="0x00" function="0x0"/>
</memballoon>
<shmem name="looking-glass">
<model type="ivshmem-plain"/>
<size unit="M">32</size>
<address type="pci" domain="0x0000" bus="0x0a" slot="0x01" function="0x0"/>
</shmem>
</devices>
<qemu:commandline>
<qemu:arg value="-acpitable"/>
<qemu:arg value="file=/home/kyle/VFIO/acpitable.bin"/>
</qemu:commandline>
</domain>