This guide assumes you are using Linux, however this procedure probably also works on other operating systems.
RPCS3
RPCS3 is a free and open-source video game console emulator for the Sony PlayStation 3 written in C++. The emulator currently runs on Windows, Linux, and Mac OS (experimental). Download and install RPCS3 for your platform of choice.
Games
.iso Files
Adding PS3 games is more involved than older consoles. You first need to download the .iso files from a platform such as r/ROMs Megathread, and more specifically the Myrient platform.
Mounting
CDEmu
Download CDEmu from your distribution’s repository (e.g. sudo zypper install cdemu-client). Additionally install the CDEmu daemon (e.g. sudo zypper install cdemu-daemon). Then, start the CDEmu daemon by running cdemu-daemon.
If the CDEmu daemon fails to start and states
failed to open control device /dev/vhba_ctl: No such file or directory!, you first need to runsudo modprobe vhba. This issue has occured to me on OpenSUSE Tumbleweed.
After successfully starting the CDEmu daemon, in another terminal session run cdemu load <device> <image_file> where <device> can be the default virtual device 0 which is created or another one of your choice, and <image_file> is the .iso file of the PS3 game. Then, mount the created volume to your system.
PS3 Disc Dumper
Download the PS3 Disc Dumper binary and give it write permissions using chmod +x ps3-disc-dumper. Run the binary and follow the instructions. The resulting created directory is the PS3 game which you can place in RPCS3 (the location in Linux is ~/.config/rpcs3/games/).