Poor harddrive performance on VM

[KAĞAN IŞILDAK <kagan.isildak@xxxxxxxxxxxxx>]

Hello,

I am using Xen 4.18. My host machine is a Dell server with dual Intel®
Xeon® Gold 6438Y+ CPUs and an NVMe SSD. I am working with Windows
virtual machines and experiencing issues related to hard disk speeds.

So far, I have conducted a total of four tests, covering disk format
and BIOS firmware. I have tried both QCOW2 and RAW disk formats and
booted the BIOS as both SeaBIOS and OVMF. In all four tests, my
read/write speed was around 50 MB/s, which is really low.

What could be causing this issue?

Note: No PV driver is installed, and I have tried mounting the disks
as both HDA and XVDA, but the results were the same.