I'm still plugging away at my Hypervisor.Framework port (now rewritten to be another accelerator like kvm).
It appears to be setting up memory regions, and I'm now working on the equivalent of kvm_cpu_exec. I see an exit code 33 on the first call, which is an invalid VMCS. This is unsurprising as I haven't yet implemented the equivalent of kvm_arch_put_registers so the register contents will presumably be illegal. Looking at kvm_arch_put_registers it appears to be pretty complicated. It appears to 'put' each individual register type, as well as putting an xsave region. I'm a bit confused why the ordinary registers 'put' are not then overwritten by the xsave put. Assuming I am only targeting processors supporting XSAVE (which I believe is reasonable given what Macs support Hypervisor.Framework), is there a reason I shouldn't merely XRSTOR (by writing the XSAVE region with the appropriate hv_ call) and ignore all the other register futzing? Or is it more complicated than that because (presumably) something sets up register states in the cpu->regs, cpu->sregs areas? I'm a bit confused as to how all this works to be honest. Any ideas / docs to point to? -- Alex Bligh
