Linux – How to increase display resolution in QEMU/KVM via virt-manager on Manjaro (host/guest)

arch linuxlinux-kvmmanjaroqemu

How to increase the guest's resolution in QEMU/KVM?

Currently, I am only able to reach a max resolution of 1280x720 on my guest virtual machine; however, I would like to increase it to 1980x1080 to match my host's resolution.

I have Manjaro 18.0.4 running on both my host and on my guest. Here are the steps I followed to setup the system:

On the host OS

sudo pacman -Syu
sudo pacman -S virt-manager qemu vde2 ebtables dnsmasq bridge-utils openbsd-netcat
sudo systemctl enable libvirtd.service
sudo systemctl start libvirtd.service

Then I created a new virtual machine using virt-manager as follows:

Display server: Spice server + default options
Video: QXL + vgamem="32768"
View > Scale Display: Never + Autoresize VM with windows (this option probably are irrelevant to the problem)

On the guest OS

sudo pacman -S spice-vdagent xf86-video-qxl

However the max resolution available is still 1280x720. I would like make changes within virt-manager if possible.

P.S.1: The Scale Display options work but that is not what I want to achieve as the scaled graphics aren't great.

P.S.2: I would like to keep with Spice/QXL setup as it seems better than VGA

Thanks

Best Answer

This is an issue related to Manjaro running as the guest OS.

The solution is to remove the default xorg configuration in 90-mhwd.conf on the guest OS as posted in this forum:

sudo rm /etc/X11/xorg.conf.d/90-mhwd.conf

Related Solutions

Linux – How to increase the visualized screen resolution on QEMU / KVM

Add the '-vga std' flag to the command line

Basically, the virtual machine loads its own virtual driver. Hardware virtualization is necessary because virtual disk images are often copied to many different systems with diverse architectures. By abstracting the hardware the vm images are capable of doing this.

By using the '-vga std' flag you make the GuestOS load a standard VGA device that should be able to support resolution equal-to-or-greater than your physical card can handle.

For more info check out this article.

Note: If you're using an older version of kvm/qemu the you might need to use the '-std-vga' flag instead.

If you aren't able to reach resolutions greater than 1600x1200 note that there are still some issues with this option.

Linux – virt-manager kvm modules are not available

Also in my case (Fedora 16 32 bits) I've installed everything ...also I've activated bios visualization vt-x... cpu is compatible .. but the same error (KVM is not available. This may mean the KVM package is not installed,or the KVM kernel modules are not loaded. Your virtual machines may perform poorly.)

Finaly I've executed manualy modprobe kvm_intel and all done.

[root@monsterm ~]# grep vmx /proc/cpuinfo
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm ida dts tpr_shadow vnmi flexpriority
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm ida dts tpr_shadow vnmi flexpriority

lshw | grep vmx
[root@monsterm ~]# lshw | grep vmx
          capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe x86-64 constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm ida tpr_shadow vnmi flexpriority cpufreq


# check kvm kernel modules
modprobe kvm_intel
lsmod | grep kvm

[root@monsterm ~]# lsmod | grep kvm*
kvm_intel             126289  0 
kvm                   356309  1 kvm_intel

Related Question

Linux – the difference and relationship between kvm, virt-manager, qemu and libvirt