Missing Linux Kernel mitigations for ‘iTLB multihit’ hardware vulnerabilities

Missing Linux Kernel mitigations for ‘iTLB multihit’ hardware vulnerabilities

I don't know how to mitigate iTLB multihit vulnerability.

/sys/devices/system/cpu/vulnerabilities/itlb_multihit | KVM: Vulnerable

Found this: iTLB multihit, But i have no access to the host machine where the VM is hosted. Is it possible to fix or mitigate this vulnerability from the guest operating system ?

System specification: 
Ubuntu Server 20.04 LTS
Kernel: 5.4.0-125-generic

I was trying to modify GRUB_CMDLINE_LINUX_DEFAULT="maybe-ubiquity mitigations=on" and append mitigations=on but it doesn't provide any result.