KVM: x86/mmu: move pdptrs out of the MMU

PDPTRs are part of the CPU state.  A bit unconventionally, they are
reached via vcpu->arch.walk_mmu instead of being stored in vcpu->arch
directly.  That is nice in principle---it would allow TDP shadow paging
to have its own PDPTRs---but it is not necessary, because EPT has no
PDPTRs and NPT does not cache them.

Since kvm_pdptr_read does not otherwise need the MMU, drop the pdptrs
from the MMU altogether.  There is however something to be careful
about, in that PDPTRs are now not stored separately in root_mmu and
nested_mmu for L1 and L2 guests.  In practice this was already not
an issue:

- for EPT the VMCS0x has to keep them up to date; and for the purpose
  of emulation they are always loaded from the VMCS on vmentry/vmexit,
  thanks to the clearing of dirty and available register bitmaps in
  vmx_switch_vmcs()

- for NPT, VCPU_EXREG_PDPTR is similarly cleared for nNPT, which does
  not cache the PDPTRs; while for non-nNPT the PDPTRs are loaded
  together with the load of CR3.

Note that page table PDPTRs are not affected, since they are stored
in pae_root.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20260530165545.25599-6-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

0 files changed, 0 insertions, 0 deletions