1 files changed, 44 insertions, 3 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 9631c90907eb..c237b810b03f 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1975,6 +1975,7 @@ static void *m2v(phys_addr_t maddr)
         return __ka(m2p(maddr));
 }
 
+/* Set the page permissions on an identity-mapped pages */
 static void set_page_prot(void *addr, pgprot_t prot)
 {
         unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
@@ -2159,6 +2160,8 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
 }
 #endif  /* CONFIG_X86_64 */
 
+static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss;
+
 static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 {
         pte_t pte;
@@ -2179,15 +2182,28 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 #else
         case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
 #endif
-#ifdef CONFIG_X86_LOCAL_APIC
-        case FIX_APIC_BASE:     /* maps dummy local APIC */
-#endif
         case FIX_TEXT_POKE0:
         case FIX_TEXT_POKE1:
                 /* All local page mappings */
                 pte = pfn_pte(phys, prot);
                 break;
 
+#ifdef CONFIG_X86_LOCAL_APIC
+        case FIX_APIC_BASE:     /* maps dummy local APIC */
+                pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
+                break;
+#endif
+
+#ifdef CONFIG_X86_IO_APIC
+        case FIX_IO_APIC_BASE_0 ... FIX_IO_APIC_BASE_END:
+                /*
+                 * We just don't map the IO APIC - all access is via
+                 * hypercalls.  Keep the address in the pte for reference.
+                 */
+                pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
+                break;
+#endif
+
         case FIX_PARAVIRT_BOOTMAP:
                 /* This is an MFN, but it isn't an IO mapping from the
                    IO domain */
@@ -2212,6 +2228,29 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 #endif
 }
 
+__init void xen_ident_map_ISA(void)
+{
+        unsigned long pa;
+
+        /*
+         * If we're dom0, then linear map the ISA machine addresses into
+         * the kernel's address space.
+         */
+        if (!xen_initial_domain())
+                return;
+
+        xen_raw_printk("Xen: setup ISA identity maps\n");
+
+        for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) {
+                pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO);
+
+                if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0))
+                        BUG();
+        }
+
+        xen_flush_tlb();
+}
+
 static __init void xen_post_allocator_init(void)
 {
         pv_mmu_ops.set_pte = xen_set_pte;
@@ -2320,6 +2359,8 @@ void __init xen_init_mmu_ops(void)
         pv_mmu_ops = xen_mmu_ops;
 
         vmap_lazy_unmap = false;
+
+        memset(dummy_mapping, 0xff, PAGE_SIZE);
 }
 
 /* Protected by xen_reservation_lock. */