Re: [PATCH] KVM: nVMX: Don't leak L1 MMIO regions to L2

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Mon, Oct 07, 2019 at 12:07:03PM +0200, Paolo Bonzini wrote:
> As usual, nothing to say about the behavior, just about the code...
> 
> On 04/10/19 19:52, Jim Mattson wrote:
> > + * Returns:
> > + *   0 - success, i.e. proceed with actual VMEnter
> > + *  -EFAULT - consistency check VMExit
> > + *  -EINVAL - consistency check VMFail
> > + *  -ENOTSUPP - kvm internal error
> >   */
> 
> ... the error codes do not mean much here.  Can you define an enum instead?

Agreed.  Liran also suggested an enum.

> (I also thought about passing the exit reason, where bit 31 could be
> used to distinguish VMX instruction failure from an entry failure
> VMexit, which sounds cleaner if you just look at the prototype but
> becomes messy fairly quickly because you have to pass back the exit
> qualification too.  The from_vmentry argument could become u32
> *p_exit_qual and be NULL if not called from VMentry, but it doesn't seem
> worthwhile at all).

Ya.  I also tried (and failed) to find a clever solution that didn't
require a multi-state return value.  As much as I dislike returning an
enum, it's the lesser of all evils.