Of course it's possible. It was explained in the thread called "What if I want everything?". It's the best and safest way to install windows. There are many options to do it, you can use kvm-qemu, xen hypervisor, vmware esx, oracle vm server, etc...
The technology that makes this possible for *nix-systems has been around since way before Windows or even the x86 platform was even invented, it was originally developed by IBM in the 1960's, with the first ever "type 1 hypervisor" called IBM z/VM.
On x86, it took much longer to have this capability, as linux had to come onto the scene first, but as linux was adopted by the major technology creating companies as standard almost immediately after it came out in 1991, including by IBM, the evolution of hypervisors sped up even before Windows was really popular, to the point now where there are at least 20 type 1 hypervisors by different companies and organizations, all based on linux, and only a small minority of them are not free and open source software, so you have a wide selection of methods to do this.
kvm-qemu is a RedHat driven project mainly, it's entirely free and open source and native to the linux kernel, so I would recommend using that. It offers the best performance and has the most features, and is known for it's stability (which is an issue with some closed source hypervisors like VMWare ESX, which used to be very popular in enterprises, but is also known for having system crashes that resemble windows system crashes, only it's not called BSOD but rather PSOD).
I use it myself, I've used kvm and Xen for years without any problem whatsoever for years now. To have maximum performance in Windows for gaming, you might want to use paravirtualisation of a graphics card, if gaming in Windows is something that you want to do.
The Windows install is slow and chaotic in comparison to a linux install, and it takes a long time, but in a virtual container, it installs much faster than on bare metal, uses less storage space (even though it still uses an enormous amount in comparison) and it doesn't need to "phone home" like on a bare metal install, you can rip the windows install DVD ISO and mount it on your machine, so that it can see the install medium everytime it boots up in the container, and that suffices, you don't even have to enter the software key, you can just cancel it (in fact, you have to cancel it or it will not finish install properly and will show activation pop-up all the time, if you cancel the software key entry, it will just work as well as windows can ever work). You can also ignore most windows updates, and cherry pick just those that actually do something useful, which saves a lot of space and keeps the windows install much faster than with all updates on a bare metal install.