KVM: x86/mmu: Avoid collision with !PRESENT SPTEs in TDP MMU lpage stats

Factor in whether or not the old/new SPTEs are shadow-present when
adjusting the large page stats in the TDP MMU.  A modified MMIO SPTE can
toggle the page size bit, as bit 7 is used to store the MMIO generation,
i.e. is_large_pte() can get a false positive when called on a MMIO SPTE.
Ditto for nuking SPTEs with REMOVED_SPTE, which sets bit 7 in its magic
value.

Opportunistically move the logic below the check to verify at least one
of the old/new SPTEs is shadow present.

Use is/was_leaf even though is/was_present would suffice.  The code
generation is roughly equivalent since all flags need to be computed
prior to the code in question, and using the *_leaf flags will minimize
the diff in a future enhancement to account all pages, i.e. will change
the check to "is_leaf != was_leaf".

Reviewed-by: David Matlack <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>

Fixes: 1699f65c8b65 ("kvm/x86: Fix 'lpages' kvm stat for TDM MMU")
Cc: [email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Mingwei Zhang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

0 files changed, 0 insertions, 0 deletions