Hi Jatin,
The RedHat documentation on this is extremely helpful. It's
so helpful that I use it as a reference on completely
different distributions.
VMWare does a pretty good job of guiding you and giving you
defaults that are sensible. With Libvirt/QEMU/KVM, you need to
get an idea of those and enable them yourself.
For example, I see that you are using qcow2 files, but if
you don't need the features it provides, then using block
devices (usually logical volumes in a volume group) directly
for VM disks may be significantly faster. It also depends on
how caching is configured. The manuals will step you through
all of that. Pay special attention to storage, because it's
the first bottleneck a lot of applications hit.