These can be ignored:
xnf wrote:00:00:04.020150 GIM: Using provider 'HyperV' (Implementation version: 0)
00:00:04.020180 GIM: HyperV: Reporting vendor as 'VBoxVBoxVBox'
They refer to the Paravirtualization channel, which is a comm channel provided by modern virtualization-aware OS's to talk to the hypervisor they're running on. Windows 7 & later use this channel to communicate with the hypervisor, and Windows speaks Hyper-V in paravirtualization. This is not the Hyper-V that blocks Virtualbox.
This is the big kahuna:
xnf wrote:HM: HMR3Init: VT-x w/ nested paging and unrestricted guest execution hw support
You have full VT-x with no interference from host Hyper-V.
If you did have a Hyper-V service running, you'd see this in the log:
HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...
It's either "HMR3Init: VT-x..." or "HMR3Init: Attempting fall back to NEM". Your host is good, no Hyper-V.