vmwgfx acceleration in VMware workstation player is not currently working with oreo-x86, but it is working with nougat-x86
virtualbox 5.x works with sw rendering provided by Swiftshader, use at least 2Gbytes of RAM and 128Mb of Video Ram. SWrendering is not as performant as HW acceleration.
virtualbox 6.0rc1 supports VMSGVA, which is API compatible with with svga/vmwgfx, but even if nougat-x86 should work (as it works on VMware player) I only see top left white cursor in text mode, not graphic mode set.
good news (opportunity) to use VMSVGA as accelerated driver in virtualbox (which is more user friendly than VMware player)