Quad Core host with hyper-threading, how many processors to configure in VirtualBox?

I have a quad-core i7 processor with hyperthreading (8 logical cores), when I configured a virtual machine to use 8 processors, VirtualBox gave me a warning saying that I only have four cores (which is true) and that this may cause a performance issue. But hyper-threading is a hardware feature, so the OS sees 8 cores and it sends instructions to all 8. What if setting it to 4 caused the VM to use 2 cores (4 threads) instead of 4 simultaneous threads (on all 4 cores)? Does the warning I got take into account that my machine has hyper-threading?