Sean Christopherson <sean.j.christopherson@xxxxxxxxx> writes:
> On Mon, Sep 30, 2019 at 12:58:53PM +0200, Vitaly Kuznetsov wrote:
>> Sean Christopherson <sean.j.christopherson@xxxxxxxxx> writes:
>>
>> > Handle caching CR3 (from VMX's VMCS) into struct kvm_vcpu via the common
>> > cache_reg() callback and drop the dedicated decache_cr3(). The name
>> > decache_cr3() is somewhat confusing as the caching behavior of CR3
>> > follows that of GPRs, RFLAGS and PDPTRs, (handled via cache_reg()), and
>> > has nothing in common with the caching behavior of CR0/CR4 (whose
>> > decache_cr{0,4}_guest_bits() likely provided the 'decache' verbiage).
>> >
>> > Note, this effectively adds a BUG() if KVM attempts to cache CR3 on SVM.
>> > Opportunistically add a WARN_ON_ONCE() in VMX to provide an equivalent
>> > check.
>>
>> Just to justify my idea of replacing such occasions with
>> KVM_INTERNAL_ERROR by setting a special 'kill ASAP' bit somewhere:
>>
>> This WARN_ON_ONCE() falls in the same category (IMO).
>
> Maybe something like KVM_BUG_ON? E.g.:
>
> #define KVM_BUG_ON(kvm, cond) \
> ({ \
> int r; \
> \
> if (r = WARN_ON_ONCE(cond)) \
> kvm->vm_bugged = true; \
> r; \
> )}
>
Yes, that's more or less what I meant! (to me 'vm_bugged' sounds like
there was a bug in the VM but the bug is actually in KVM so maybe
something like 'kvm_internal_bug' to make it explicit?)
--
Vitaly
