Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 14ffd97..97b21e7 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Kernel-based Virtual Machine driver for Linux
  *
@@ -12,10 +13,6 @@
  * Authors:
  *   Yaniv Kamay  <yaniv@qumranet.com>
  *   Avi Kivity   <avi@qumranet.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
- *
  */
 
 /*
@@ -140,16 +137,36 @@
 	pt_element_t *table;
 	struct page *page;
 
-	npages = get_user_pages_fast((unsigned long)ptep_user, 1, 1, &page);
-	/* Check if the user is doing something meaningless. */
-	if (unlikely(npages != 1))
-		return -EFAULT;
+	npages = get_user_pages_fast((unsigned long)ptep_user, 1, FOLL_WRITE, &page);
+	if (likely(npages == 1)) {
+		table = kmap_atomic(page);
+		ret = CMPXCHG(&table[index], orig_pte, new_pte);
+		kunmap_atomic(table);
 
-	table = kmap_atomic(page);
-	ret = CMPXCHG(&table[index], orig_pte, new_pte);
-	kunmap_atomic(table);
+		kvm_release_page_dirty(page);
+	} else {
+		struct vm_area_struct *vma;
+		unsigned long vaddr = (unsigned long)ptep_user & PAGE_MASK;
+		unsigned long pfn;
+		unsigned long paddr;
 
-	kvm_release_page_dirty(page);
+		down_read(&current->mm->mmap_sem);
+		vma = find_vma_intersection(current->mm, vaddr, vaddr + PAGE_SIZE);
+		if (!vma || !(vma->vm_flags & VM_PFNMAP)) {
+			up_read(&current->mm->mmap_sem);
+			return -EFAULT;
+		}
+		pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+		paddr = pfn << PAGE_SHIFT;
+		table = memremap(paddr, PAGE_SIZE, MEMREMAP_WB);
+		if (!table) {
+			up_read(&current->mm->mmap_sem);
+			return -EFAULT;
+		}
+		ret = CMPXCHG(&table[index], orig_pte, new_pte);
+		memunmap(table);
+		up_read(&current->mm->mmap_sem);
+	}
 
 	return (ret != orig_pte);
 }
@@ -158,14 +175,15 @@
 				  struct kvm_mmu_page *sp, u64 *spte,
 				  u64 gpte)
 {
-	if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL))
+	if (is_rsvd_bits_set(vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL))
 		goto no_present;
 
 	if (!FNAME(is_present_gpte)(gpte))
 		goto no_present;
 
 	/* if accessed bit is not supported prefetch non accessed gpte */
-	if (PT_HAVE_ACCESSED_DIRTY(&vcpu->arch.mmu) && !(gpte & PT_GUEST_ACCESSED_MASK))
+	if (PT_HAVE_ACCESSED_DIRTY(vcpu->arch.mmu) &&
+	    !(gpte & PT_GUEST_ACCESSED_MASK))
 		goto no_present;
 
 	return false;
@@ -480,7 +498,7 @@
 static int FNAME(walk_addr)(struct guest_walker *walker,
 			    struct kvm_vcpu *vcpu, gva_t addr, u32 access)
 {
-	return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr,
+	return FNAME(walk_addr_generic)(walker, vcpu, vcpu->arch.mmu, addr,
 					access);
 }
 
@@ -509,7 +527,7 @@
 
 	gfn = gpte_to_gfn(gpte);
 	pte_access = sp->role.access & FNAME(gpte_access)(gpte);
-	FNAME(protect_clean_gpte)(&vcpu->arch.mmu, &pte_access, gpte);
+	FNAME(protect_clean_gpte)(vcpu->arch.mmu, &pte_access, gpte);
 	pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
 			no_dirty_log && (pte_access & ACC_WRITE_MASK));
 	if (is_error_pfn(pfn))
@@ -522,6 +540,7 @@
 	mmu_set_spte(vcpu, spte, pte_access, 0, PT_PAGE_TABLE_LEVEL, gfn, pfn,
 		     true, true);
 
+	kvm_release_pfn_clean(pfn);
 	return true;
 }
 
@@ -595,16 +614,18 @@
 static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 			 struct guest_walker *gw,
 			 int write_fault, int hlevel,
-			 kvm_pfn_t pfn, bool map_writable, bool prefault)
+			 kvm_pfn_t pfn, bool map_writable, bool prefault,
+			 bool lpage_disallowed)
 {
 	struct kvm_mmu_page *sp = NULL;
 	struct kvm_shadow_walk_iterator it;
 	unsigned direct_access, access = gw->pt_access;
 	int top_level, ret;
+	gfn_t gfn, base_gfn;
 
 	direct_access = gw->pte_access;
 
-	top_level = vcpu->arch.mmu.root_level;
+	top_level = vcpu->arch.mmu->root_level;
 	if (top_level == PT32E_ROOT_LEVEL)
 		top_level = PT32_ROOT_LEVEL;
 	/*
@@ -616,7 +637,7 @@
 	if (FNAME(gpte_changed)(vcpu, gw, top_level))
 		goto out_gpte_changed;
 
-	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+	if (!VALID_PAGE(vcpu->arch.mmu->root_hpa))
 		goto out_gpte_changed;
 
 	for (shadow_walk_init(&it, vcpu, addr);
@@ -645,35 +666,48 @@
 			link_shadow_page(vcpu, it.sptep, sp);
 	}
 
-	for (;
-	     shadow_walk_okay(&it) && it.level > hlevel;
-	     shadow_walk_next(&it)) {
-		gfn_t direct_gfn;
+	/*
+	 * 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;
 
+	trace_kvm_mmu_spte_requested(addr, gw->level, pfn);
+
+	for (; shadow_walk_okay(&it); shadow_walk_next(&it)) {
 		clear_sp_write_flooding_count(it.sptep);
+
+		/*
+		 * We cannot overwrite existing page tables with an NX
+		 * large page, as the leaf could be executable.
+		 */
+		disallowed_hugepage_adjust(it, gfn, &pfn, &hlevel);
+
+		base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+		if (it.level == hlevel)
+			break;
+
 		validate_direct_spte(vcpu, it.sptep, direct_access);
 
 		drop_large_spte(vcpu, it.sptep);
 
-		if (is_shadow_present_pte(*it.sptep))
-			continue;
-
-		direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
-
-		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
-				      true, direct_access);
-		link_shadow_page(vcpu, it.sptep, sp);
+		if (!is_shadow_present_pte(*it.sptep)) {
+			sp = kvm_mmu_get_page(vcpu, base_gfn, addr,
+					      it.level - 1, true, direct_access);
+			link_shadow_page(vcpu, it.sptep, sp);
+			if (lpage_disallowed)
+				account_huge_nx_page(vcpu->kvm, sp);
+		}
 	}
 
-	clear_sp_write_flooding_count(it.sptep);
 	ret = mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault,
-			   it.level, gw->gfn, pfn, prefault, map_writable);
+			   it.level, base_gfn, pfn, prefault, map_writable);
 	FNAME(pte_prefetch)(vcpu, gw, it.sptep);
-
+	++vcpu->stat.pf_fixed;
 	return ret;
 
 out_gpte_changed:
-	kvm_release_pfn_clean(pfn);
 	return RET_PF_RETRY;
 }
 
@@ -740,9 +774,11 @@
 	int r;
 	kvm_pfn_t pfn;
 	int level = PT_PAGE_TABLE_LEVEL;
-	bool force_pt_level = false;
 	unsigned long mmu_seq;
 	bool map_writable, is_self_change_mapping;
+	bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) &&
+				is_nx_huge_page_enabled();
+	bool force_pt_level = lpage_disallowed;
 
 	pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
 
@@ -821,6 +857,7 @@
 			walker.pte_access &= ~ACC_EXEC_MASK;
 	}
 
+	r = RET_PF_RETRY;
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
 		goto out_unlock;
@@ -829,19 +866,15 @@
 	if (make_mmu_pages_available(vcpu) < 0)
 		goto out_unlock;
 	if (!force_pt_level)
-		transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
+		transparent_hugepage_adjust(vcpu, walker.gfn, &pfn, &level);
 	r = FNAME(fetch)(vcpu, addr, &walker, write_fault,
-			 level, pfn, map_writable, prefault);
-	++vcpu->stat.pf_fixed;
+			 level, pfn, map_writable, prefault, lpage_disallowed);
 	kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
-	spin_unlock(&vcpu->kvm->mmu_lock);
-
-	return r;
 
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
 	kvm_release_pfn_clean(pfn);
-	return RET_PF_RETRY;
+	return r;
 }
 
 static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp)
@@ -893,7 +926,8 @@
 			pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);
 
 			if (mmu_page_zap_pte(vcpu->kvm, sp, sptep))
-				kvm_flush_remote_tlbs(vcpu->kvm);
+				kvm_flush_remote_tlbs_with_address(vcpu->kvm,
+					sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level));
 
 			if (!rmap_can_add(vcpu))
 				break;
@@ -1004,7 +1038,7 @@
 		gfn = gpte_to_gfn(gpte);
 		pte_access = sp->role.access;
 		pte_access &= FNAME(gpte_access)(gpte);
-		FNAME(protect_clean_gpte)(&vcpu->arch.mmu, &pte_access, gpte);
+		FNAME(protect_clean_gpte)(vcpu->arch.mmu, &pte_access, gpte);
 
 		if (sync_mmio_spte(vcpu, &sp->spt[i], gfn, pte_access,
 		      &nr_present))