Yeah, the kvm part is optional of course.
Thing with gaming in linux is that it's sometimes expensive in terms of system resources, as not all games are native linux games, in fact, most older AAA-titles are windows versions with a dedicated proprietary wrapper, not even wine, so they are often very wasteful with system resources because of any number of bugs.
An example (I know, again the same example I always give): CS:GO: the system requirements for Windows are very moderate, it's an older game, it has become heavier over the years with all of the bloatware Valve keeps adding, but it's still a pretty basic game, mostly CPU bound, even an Intel iGPU with only two execution modules can easily render it at 1080p, if the CPU is strong enough. That's on Windows... on linux, you actually need a more powerful machine, if you install the linux version of the game provided by Valve. In that case, you get basically the Windows version, with a dedicated proprietary wrapper that limits the performance enormously. If, on the other hand, you install the Windows version in wine in linux, you get much better performance, but you also need to do a few tweaks to optimize it for your system.
Other games, that are made with a platform-independent engine, like Trine 2 for instance, will run a bit better on linux than on Windows on the same hardware, but the difference is not spectacular, you get a bit sharper graphics, a bit better colours, a bit less blotching and bleeding in the graphics because of the better performing shaders, and a few fps more, but it's not like you get a huge performance bonus.
Games that are made with an open source game engine for linux, will of course perform radically better. Games like Xonotic, Sauerbraten, Red Eclipse, Urban Terror, Minetest, etc... will give you crazy high fps values on any gaming grade hardware from the last 7-8 years. A game like Xonotic is about comparable to an Unreal Engine game for Windows in terms of engine capabilities and texture/graphics detail and features, but you'll get at least 30 % more fps across the board for the same detail and filtering settings.
The grim reality is that the proof of the pudding for gaming on linux still has to come. The real question for Windows-targeted gaming hardware has been "does it run crysis?" since 2007 or so, well, that's also the question for linux, because the new cryengine will both come out in a native linux version, and come out for windows with Mantle, so when that has happened, then we'll have a direct comparison. At the moment though, we don't really have that, we only have a marginally better performance for platform-independent engines in direct comparison situations, and we have indirect comparison situations.
The other aspect is that we're at a strange intermediate time in terms of hardware. On the one hand, there is the Intel 2011-3 platform, which offers a true performance increase, but it's also very expensive, and I would certainly not recommend it for gaming, because of how much it costs, and how much uncertainties there still are with regards to the platform in terms of linux support, but also in terms of Windows support. These are pretty complex machines with DDR4, they are first generation, and they are overly expensive. Early adopters are very brave, and not often rewarded for their effort. AMD is coming out soon with a completely new paradigm in terms of x86 crossover platforms, software is shifting towards the cloud, etc... a lot of paradigms will probably face radical changes in the very near future, and there is absolutely no guarantee at all that gamers will even get part of their X99 investment out of it at this point. Even heavily Intel-sponsored MLG gamers, still use Haswell and Haswell-refresh systems on 1150. At the Microsoft Surface 3 events, MLG gamers were hired to play games in public on the Surface 3. Also fpfps and CS players were hired, but they had to play Heartstone or LoL instead of their games, because of the huge throttling issues with the Intel chips in the Surface 3, that doesn't have a high performance cooling system. The FX8k from AMD has a similar problem, it is also a chip that requires serious cooling because of the thermal density. An FX6k from AMD doesn't have that problem, because it's exactly the same as an FX8k, but with a disabled module, so lower thermal density. On Windows, I would go for an FX4k, because of the even lower thermal density and the even lower price, but better game performance in Windows because of the higher overclock capacity, or an Intel Pentium Anniversary Edition or i3 for those that need more mobo features and don't want to overclock, but on Linux, I would go for the FX6k, because linux actually knows how to really leverage those extra cores, and it's still a 1.2 billion transistors chip, it's good for several years of above average performance on linux, and it doesn't cost that much, so that people on a very low budget can still have a PC that does everything they throw at it, or people that don't use their desktop PC all that much (like me), but like to focus more on buying all kinds of post-PC era devices, devkits, and other electronics hardware.
Until a few years ago, I would always buy the latest and greatest hardware to play with, but it's often frustrating how little return on investment you actually get from it during the first 6-18 months of the product lifecycle of these things. I always use very bleeding edge linux distros on desktops and laptops (as opposed to on servers sometimes), so I'm not even talking about lack of feature support in older Linux kernels, I'm talking about waiting for BIOS patches, GPU driver patches in Windows, microcode patches and CPU hardware bug workarounds, time wasted on getting to know how to optimally configure the new hardware, etc... and to be honest, I've had enough of that. I want to buy something and be able to use it right away, to be able to go on the internet or talk to a professional, and know exactly what I will be able to do with it, not the marketing talk, not the false promises, but the actual bottom line. I'm 100% sure that when I go to the store tomorrow and buy a cheap FX6k based system, I'll have no troubles with either any linux distro from Slackware over Debian Stable all the way to Arch or Fedora or Gentoo, and I'll have absolutely no problems with BSD or Windows either, and the system will do exactly as expected and without problems of any kind. I don't care that it won't run OSX on bare metal, because I can run that in a kvm/qemu container without any compatibility issues, because I can emulate the hardware that I don't have, and I won't be gaming in OSX anyway... I want the simple, comfortable solution.
A PC is a really common object with a diminishing value in people's lives. With the unlocking of cloud computing to the masses, it is getting ever harder to justify the investment in "premium" and "blazing white hot" PC hardware.
I've been using linux since the 1990's, and I see things differently because by using linux, my requirements are quite different and I look for solutions in another way than software console users tied to licenses with limited compatibility and feature access would. I would not buy a 3000 USD PC with white hot latest and greatest hardware for video rendering, because I know that there will be problems (and the serious problems with failing acceleration of rendering in Premiere and Vegas on Windows on recent nVidia cards is such a well-known problem... even Dave from EEVBlog made a video on YouTube about it lolz...), and it's not worth the investment in full. I would spend the same amount (or even a bit less actually, I would have enough budget left to also get a nice tablet to do remote control and monitoring with) on a nice client PC, for instance an FX6k system like described above, and a couple of headless boards with FX8k processors and FirePro's clustered together, for a nice potent workstation with it's own rendering farm. I would gain a lot of time, because the technology and software is tried and tested, it's what all broadcast stations, animators, etc... use, because it just works without headaches and without this or that driver and this or that license and this or that patch, blah blah, it's plug and play, crimp a few RJ45 connectors, plug in gigalan, press power, load up an OpenSuSE net install on all systems at the same time, go for it... same amount of money spent, no time lost, and much fewer possible points of failure, and a much more multi-functional setup, with a much longer shelf life, and because it's a combined package consisting of multiple parts, it's cheaper to upgrade when necessary and keep at a maximum performance level, and it will most certainly outperform any single standalone workstation, and not by a small margin lol.