(As, for some unknown reason, my replies to two old posts don't appear in the overview pane of this community, I repeat the concept here...)
This worked for me, with OS X 10.11 host and guest (YMMV), on a late 2013 15" Retina MacBook Pro:
Enable HiDPI mode on a VMware Fusion OS X 10.9 Mavericks Vagrant VM · GitHub
In a few words, first of all enable full Retina resolution for the OS X VM in its settings, then run this command in the VM's Terminal:
sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true
... reboot the VM, and finally set the VM's Display resolution to the scaled value (half of the maximum), in the VM's System Preferences: for example, if the default Retina resolution is 2880x1800 (in full screen view), then choose 1440x900 (HiDPI).
This should give you the same pixel-doubled resolution in the guest as in the host.