On Tue, May 02, 2023, Anish Moorthy wrote: > On Tue, May 2, 2023 at 1:41 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > > > If KVM triggers a WARN_ON_ONCE(), then that's an issue. Though looking at the > > code, the cui() aspect is a moot point. As I stated in the previous discussion, > > the WARN_ON_ONCE() in question needs to be off-by-default. > > > > : Hmm, one idea would be to have the initial -EFAULT detection fill kvm_run.memory_fault, > > : but set kvm_run.exit_reason to some magic number, e.g. zero it out. Then KVM could > > : WARN if something tries to overwrite kvm_run.exit_reason. The WARN would need to > > : be buried by a Kconfig or something since kvm_run can be modified by userspace, > > : but other than that I think it would work. > > Ah, ok: I thought using WARN_ON_ONCE instead of WARN might have > obviated the Kconfig. I'll go add one. Don't put too much effort into anything at this point. I'm not entirely convinced that it's worth carrying a Kconfig for this one-off case (my "suggestion" was mostly just me spitballing), and at a quick glance through the rest of the series, I'll definitely have more comments when I do a full review, i.e. things may change too.
