On Wed, Jan 05, 2022, Michael Roth wrote:
> On Wed, Jan 05, 2022 at 07:40:57PM +0000, Sean Christopherson wrote:
> > As for ucall_init(), I think the best approach would be to make kvm_vm_elf_load()
> > a static and replace all calls with:
> >
> > kvm_vm_load_guest(vm);
> >
> > where its implementation is:
> >
> > void kvm_vm_load_guest(struct kvm_vm *vm)
> > {
> > kvm_vm_elf_load(vm, program_invocation_name);
> >
> > ucall_init(vm);
> > }
> >
> > The logic being that if a test creates a VM but never loads any code into the guest,
> > e.g. kvm_create_max_vcpus, then it _can't_ make ucalls.
>
> Makes sense. And if different ops are needed for vmgexit()/tdcall() it
> could be something like (if based on patches 1-5 of this series, and
> extending vm_guest_mode as you suggested earlier):
>
> void kvm_vm_load_guest(struct kvm_vm *vm)
> {
>
> kvm_vm_elf_load(vm, program_invocation_name);
>
> if (vm->mode == VM_MODE_SEV)
> ucall_init_ops(vm, ucall_ops_pio_vmgexit);
> else (vm->vm_type == VM_MODE_TDX)
I don't think we want to do this here, but instead down in the arch-specific
ucall_init(). Also, not sure if I was clear before (can't tell what you interpreted
based on the above snippet), but I think we'll want VM_MODE_SEV etc... to be
modifiers on top of the VA/PA stuff.
> ucall_init_ops(vm, ucall_ops_pio_tdcall);
> else
> ucall_init_ops(vm, ucall_ops_pio);
>
> Shame we have to update all the kvm_vm_elf_load() call-sites, but
> they'd end up potentially breaking things if left as-is anyway.
>
> Were you planning on sending patches for these changes, or should I incorporate
> your prototype and take a stab at the other changes as part of v2 of this
> series?
Nope, all yours. Thanks!
