KVM: x86/mmu: Tweak PSE hugepage handling to avoid 2M vs 4M conundrum

Change the PSE hugepage handling in walk_addr_generic() to fire on any
page level greater than PT_PAGE_TABLE_LEVEL, a.k.a. PG_LEVEL_4K.  PSE
paging only has two levels, so "== 2" and "> 1" are functionally the
same, i.e. this is a nop.

A future patch will drop KVM's PT_*_LEVEL enums in favor of the kernel's
PG_LEVEL_* enums, at which point "walker->level == PG_LEVEL_2M" is
semantically incorrect (though still functionally ok).

No functional change intended.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428005422.4235-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index efec7d2..ca39bd3 100644 (file)
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -436,7 +436,7 @@ retry_walk:
        gfn = gpte_to_gfn_lvl(pte, walker->level);
        gfn += (addr & PT_LVL_OFFSET_MASK(walker->level)) >> PAGE_SHIFT;
 
-       if (PTTYPE == 32 && walker->level == PT_DIRECTORY_LEVEL && is_cpuid_PSE36())
+       if (PTTYPE == 32 && walker->level > PT_PAGE_TABLE_LEVEL && is_cpuid_PSE36())
                gfn += pse36_gfn_delta(pte);
 
        real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access, &walker->fault);