Re: [PATCH 00/13] KVM: x86: Add a cap to disable NX hugepages on a VM

[Sean Christopherson]

On Thu, Mar 10, 2022, Ben Gardon wrote:
> Those patches are a lot of churn, but at least to me, they make the
> code much more readable. Currently there are many functions which just
> pass along 0 for the memslot, and often have multiple other numerical
> arguments, which makes it hard to understand what the function is
> doing.

Yeah, my solution for that was to rip out all the params.  E.g. the most used
function I ended up with is

  static inline struct kvm_vm *vm_create_with_one_vcpu(struct kvm_vcpu **vcpu,
						     void *guest_code)
  {
	return __vm_create_with_one_vcpu(vcpu, 0, guest_code);
  }

and then the usage is

	vm = vm_create_with_one_vcpu(&vcpu, guest_main);

	supp_cpuid = kvm_get_supported_cpuid();
	cpuid2 = vcpu_get_cpuid(vcpu);

My overarching complaint with the selftests is that they make the hard things hard,
and the easy things harder.  If a test wants to be backed by hugepages, it shouldn't
have to manually specify a memslot.

Let me post my selftests rework as RFC (_very_ RFC at this point).  I was hoping to
do more than compile test before posting anything, but it's going to be multiple
weeks before I'll get back to it.  Hopefully it'll start a discussion on actually
rewriting the framework so that writing new tests is less painful, and so that every
new thing that comes along doesn't require poking at 50 different tests.