diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index abe8e4b..483bad7 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -285,7 +285,7 @@ check_v8086_mode(struct pt_regs *regs, unsigned long address,
 		tsk->thread.screen_bitmap |= 1 << bit;
 }
 
-static void dump_pagetable(unsigned long address)
+void dump_pagetable(unsigned long address)
 {
 	__typeof__(pte_val(__pte(0))) page;
 
@@ -603,6 +603,10 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
 	printk_address(regs->ip, 1);
 
 	dump_pagetable(address);
+	printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE0));
+	dump_pagetable(fix_to_virt(KM_PTE0));
+	printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE1));
+	dump_pagetable(fix_to_virt(KM_PTE1));
 }
 
 static noinline void
diff --git a/include/xen/swiotlb.h b/include/xen/swiotlb.h
index f35183b..5db8659 100644
--- a/include/xen/swiotlb.h
+++ b/include/xen/swiotlb.h
@@ -5,6 +5,10 @@ extern void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs);
 extern phys_addr_t xen_bus_to_phys(dma_addr_t daddr);
 extern dma_addr_t xen_phys_to_bus(phys_addr_t paddr);
 extern int xen_range_needs_mapping(phys_addr_t phys, size_t size);
+#ifdef CONFIG_XEN_PCI
 extern int xen_wants_swiotlb(void);
+#else
+static inline int xen_wants_swiotlb(void) { return 0; }
+#endif
 
 #endif /* _XEN_SWIOTLB_H */
diff --git a/mm/rmap.c b/mm/rmap.c
index 1652166..ae5d5a0 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -267,6 +267,7 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
 pte_t *page_check_address(struct page *page, struct mm_struct *mm,
 			  unsigned long address, spinlock_t **ptlp, int sync)
 {
+	struct page *pgd_page, *pte_page;
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
@@ -285,6 +286,22 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
 	if (!pmd_present(*pmd))
 		return NULL;
 
+	pgd_page = virt_to_page(mm->pgd);
+	pte_page = pmd_page(*pmd);
+
+	if (PagePinned(pgd_page) != PagePinned(pte_page)) {
+		extern void dump_pagetable(unsigned long address);
+		printk(KERN_CRIT "L4 at %p is %s contains L2 at %p which points at an L1 which is %s %s\n",
+		       pgd, PagePinned(pgd_page) ? "pinned" : "unpinned",
+		       pmd, PagePinned(pte_page) ? "pinned" : "unpinned",
+		       PageHighMem(pte_page) ? "highmem" : "lowmem");
+		printk(KERN_CRIT "address %#lx\n", address);
+		dump_pagetable(address);
+		printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE0));
+		dump_pagetable(fix_to_virt(KM_PTE0));
+		printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE1));
+		dump_pagetable(fix_to_virt(KM_PTE1));
+	}
 	pte = pte_offset_map(pmd, address);
 	/* Make a quick check before getting the lock */
 	if (!sync && !pte_present(*pte)) {