Re: [PATCH v3 27/40] KVM: x86: Move register helper declarations from kvm_host.h => regs.h

[Yosry Ahmed]

On Mon, Jun 01, 2026 at 07:24:30AM -0700, Sean Christopherson wrote:
> On Sat, May 30, 2026, Yosry Ahmed wrote:
> > On Fri, May 29, 2026 at 03:22:10PM -0700, Sean Christopherson wrote:
> > > Relocate declarations of Control/Debug Register, EFLAGS and RIP helpers
> > > from x86's kvm_host.h to regs.h, to continue trimming down kvm_host.h.
> > > 
> > > No functional change intended.
> > > 
> > > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> > > ---
> > >  arch/x86/include/asm/kvm_host.h | 17 -----------------
> > >  arch/x86/kvm/regs.h             | 17 +++++++++++++++++
> > >  2 files changed, 17 insertions(+), 17 deletions(-)
> > > 
> > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> > > index 19091d89d3cc..0f4b16b26a27 100644
> > > --- a/arch/x86/include/asm/kvm_host.h
> > > +++ b/arch/x86/include/asm/kvm_host.h
> > > @@ -2186,8 +2186,6 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen);
> > >  void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long kvm_nr_mmu_pages);
> > >  void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end);
> > >  
> > > -int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3);
> > 
> > Why are pdptrs helpers bundled with register helpers?
> 
> Page Directory Pointer Table Registers
>                              ^^^^^^^^^

LOL I assumed PDPTR is just Page Directory Pointer (i.e. PTR is
pointer). Never mind then.

> 
> Or as the SDM initially describes them, "5.4.1 PDPTE Registers".  When using
> PAE paging (not 64-bit paging), they really are CPU registers, and their lifecycle
> is tied to CR{0,3,4}.  I.e. I was thinking of them as an extension of Control
> Registers.  I can explicitly call that out in the changelog?

I don't think that's needed, it was just me being uneducated.