KVM: x86/mmu: Remove obsolete gfn restoration in FNAME(fetch)

Remove logic to retrieve the original gfn now that HugeTLB mappings are
are identified in FNAME(fetch), i.e. FNAME(page_fault) no longer adjusts
the level or gfn.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/paging_tmpl.h

@@ -636,7 +636,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
 	struct kvm_shadow_walk_iterator it;
 	unsigned direct_access, access = gw->pt_access;
 	int top_level, hlevel, ret;
-	gfn_t gfn, base_gfn;
+	gfn_t base_gfn = gw->gfn;
 
 	direct_access = gw->pte_access;
 
@@ -681,13 +681,6 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
 			link_shadow_page(vcpu, it.sptep, sp);
 	}
 
-	/*
-	 * FNAME(page_fault) might have clobbered the bottom bits of
-	 * gw->gfn, restore them from the virtual address.
-	 */
-	gfn = gw->gfn | ((addr & PT_LVL_OFFSET_MASK(gw->level)) >> PAGE_SHIFT);
-	base_gfn = gfn;
-
 	hlevel = kvm_mmu_hugepage_adjust(vcpu, gw->gfn, max_level, &pfn);
 
 	trace_kvm_mmu_spte_requested(addr, gw->level, pfn);
@@ -699,9 +692,9 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
 		 * We cannot overwrite existing page tables with an NX
 		 * large page, as the leaf could be executable.
 		 */
-		disallowed_hugepage_adjust(it, gfn, &pfn, &hlevel);
+		disallowed_hugepage_adjust(it, gw->gfn, &pfn, &hlevel);
 
-		base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+		base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
 		if (it.level == hlevel)
 			break;