Merge commit 'v3.4' into x86/urgent

11 files changed, 268 insertions, 78 deletions

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 41a7237606a3..94e91e401da9 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -134,6 +134,9 @@ KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
 KBUILD_CFLAGS += $(mflags-y)
 KBUILD_AFLAGS += $(mflags-y)
 
+archscripts:
+        $(Q)$(MAKE) $(build)=arch/x86/tools relocs
+
 ###
 # Syscall table generation
 
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index fd55a2ff3ad8..e398bb5d63bb 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -40,13 +40,12 @@ OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
 $(obj)/vmlinux.bin: vmlinux FORCE
         $(call if_changed,objcopy)
 
+targets += vmlinux.bin.all vmlinux.relocs
 
-targets += vmlinux.bin.all vmlinux.relocs relocs
-hostprogs-$(CONFIG_X86_NEED_RELOCS) += relocs
-
+CMD_RELOCS = arch/x86/tools/relocs
 quiet_cmd_relocs = RELOCS  $@
-      cmd_relocs = $(obj)/relocs $< > $@;$(obj)/relocs --abs-relocs $<
-$(obj)/vmlinux.relocs: vmlinux $(obj)/relocs FORCE
+      cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
+$(obj)/vmlinux.relocs: vmlinux FORCE
         $(call if_changed,relocs)
 
 vmlinux.bin.all-y := $(obj)/vmlinux.bin
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index d086a09c087d..11c9166c3337 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -945,9 +945,10 @@ struct mce_info {
         atomic_t                inuse;
         struct task_struct      *t;
         __u64                   paddr;
+        int                     restartable;
 } mce_info[MCE_INFO_MAX];
 
-static void mce_save_info(__u64 addr)
+static void mce_save_info(__u64 addr, int c)
 {
         struct mce_info *mi;
 
@@ -955,6 +956,7 @@ static void mce_save_info(__u64 addr)
                 if (atomic_cmpxchg(&mi->inuse, 0, 1) == 0) {
                         mi->t = current;
                         mi->paddr = addr;
+                        mi->restartable = c;
                         return;
                 }
         }
@@ -1130,7 +1132,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
                         mce_panic("Fatal machine check on current CPU", &m, msg);
                 if (worst == MCE_AR_SEVERITY) {
                         /* schedule action before return to userland */
-                        mce_save_info(m.addr);
+                        mce_save_info(m.addr, m.mcgstatus & MCG_STATUS_RIPV);
                         set_thread_flag(TIF_MCE_NOTIFY);
                 } else if (kill_it) {
                         force_sig(SIGBUS, current);
@@ -1179,7 +1181,13 @@ void mce_notify_process(void)
 
         pr_err("Uncorrected hardware memory error in user-access at %llx",
                  mi->paddr);
-        if (memory_failure(pfn, MCE_VECTOR, MF_ACTION_REQUIRED) < 0) {
+        /*
+         * We must call memory_failure() here even if the current process is
+         * doomed. We still need to mark the page as poisoned and alert any
+         * other users of the page.
+         */
+        if (memory_failure(pfn, MCE_VECTOR, MF_ACTION_REQUIRED) < 0 ||
+                           mi->restartable == 0) {
                 pr_err("Memory error not recovered");
                 force_sig(SIGBUS, current);
         }
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index b8ba6e4a27e4..e554e5ad2fe8 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -79,7 +79,6 @@ struct kvm_task_sleep_node {
         u32 token;
         int cpu;
         bool halted;
-        struct mm_struct *mm;
 };
 
 static struct kvm_task_sleep_head {
@@ -126,9 +125,7 @@ void kvm_async_pf_task_wait(u32 token)
 
         n.token = token;
         n.cpu = smp_processor_id();
-        n.mm = current->active_mm;
         n.halted = idle || preempt_count() > 1;
-        atomic_inc(&n.mm->mm_count);
         init_waitqueue_head(&n.wq);
         hlist_add_head(&n.link, &b->list);
         spin_unlock(&b->lock);
@@ -161,9 +158,6 @@ EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait);
 static void apf_task_wake_one(struct kvm_task_sleep_node *n)
 {
         hlist_del_init(&n->link);
-        if (!n->mm)
-                return;
-        mmdrop(n->mm);
         if (n->halted)
                 smp_send_reschedule(n->cpu);
         else if (waitqueue_active(&n->wq))
@@ -207,7 +201,7 @@ again:
                  * async PF was not yet handled.
                  * Add dummy entry for the token.
                  */
-                n = kmalloc(sizeof(*n), GFP_ATOMIC);
+                n = kzalloc(sizeof(*n), GFP_ATOMIC);
                 if (!n) {
                         /*
                          * Allocation failed! Busy wait while other cpu
@@ -219,7 +213,6 @@ again:
                 }
                 n->token = token;
                 n->cpu = smp_processor_id();
-                n->mm = NULL;
                 init_waitqueue_head(&n->wq);
                 hlist_add_head(&n->link, &b->list);
         } else
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 71f4727da373..5a98aa272184 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -185,10 +185,22 @@ void __init setup_per_cpu_areas(void)
 #endif
         rc = -EINVAL;
         if (pcpu_chosen_fc != PCPU_FC_PAGE) {
-                const size_t atom_size = cpu_has_pse ? PMD_SIZE : PAGE_SIZE;
                 const size_t dyn_size = PERCPU_MODULE_RESERVE +
                         PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
+                size_t atom_size;
 
+                /*
+                 * On 64bit, use PMD_SIZE for atom_size so that embedded
+                 * percpu areas are aligned to PMD.  This, in the future,
+                 * can also allow using PMD mappings in vmalloc area.  Use
+                 * PAGE_SIZE on 32bit as vmalloc space is highly contended
+                 * and large vmalloc area allocs can easily fail.
+                 */
+#ifdef CONFIG_X86_64
+                atom_size = PMD_SIZE;
+#else
+                atom_size = PAGE_SIZE;
+#endif
                 rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
                                             dyn_size, atom_size,
                                             pcpu_cpu_distance,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 91a5e989abcf..185a2b823a2d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6581,6 +6581,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
                 kvm_inject_page_fault(vcpu, &fault);
         }
         vcpu->arch.apf.halted = false;
+        vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 }
 
 bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/tools/.gitignore b/arch/x86/tools/.gitignore
new file mode 100644
index 000000000000..be0ed065249b
--- /dev/null
+++ b/arch/x86/tools/.gitignore
@@ -0,0 +1 @@
+relocs
diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index d511aa97533a..733057b435b0 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -36,3 +36,7 @@ HOSTCFLAGS_insn_sanity.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x
 $(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
 
 $(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
+
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+hostprogs-y     += relocs
+relocs: $(obj)/relocs
diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/tools/relocs.c
index fb7117a4ade1..b43cfcd9bf40 100644
--- a/arch/x86/boot/compressed/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -18,6 +18,8 @@ static void die(char *fmt, ...);
 static Elf32_Ehdr ehdr;
 static unsigned long reloc_count, reloc_idx;
 static unsigned long *relocs;
+static unsigned long reloc16_count, reloc16_idx;
+static unsigned long *relocs16;
 
 struct section {
         Elf32_Shdr     shdr;
@@ -28,52 +30,86 @@ struct section {
 };
 static struct section *secs;
 
+enum symtype {
+        S_ABS,
+        S_REL,
+        S_SEG,
+        S_LIN,
+        S_NSYMTYPES
+};
+
+static const char * const sym_regex_kernel[S_NSYMTYPES] = {
 /*
  * Following symbols have been audited. There values are constant and do
  * not change if bzImage is loaded at a different physical address than
  * the address for which it has been compiled. Don't warn user about
  * absolute relocations present w.r.t these symbols.
  */
-static const char abs_sym_regex[] =
+        [S_ABS] =
         "^(xen_irq_disable_direct_reloc$|"
         "xen_save_fl_direct_reloc$|"
         "VDSO|"
-        "__crc_)";
-static regex_t abs_sym_regex_c;
-static int is_abs_reloc(const char *sym_name)
-{
-        return !regexec(&abs_sym_regex_c, sym_name, 0, NULL, 0);
-}
+        "__crc_)",
 
 /*
  * These symbols are known to be relative, even if the linker marks them
  * as absolute (typically defined outside any section in the linker script.)
  */
-static const char rel_sym_regex[] =
-        "^_end$";
-static regex_t rel_sym_regex_c;
-static int is_rel_reloc(const char *sym_name)
+        [S_REL] =
+        "^(__init_(begin|end)|"
+        "__x86_cpu_dev_(start|end)|"
+        "(__parainstructions|__alt_instructions)(|_end)|"
+        "(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
+        "_end)$"
+};
+
+
+static const char * const sym_regex_realmode[S_NSYMTYPES] = {
+/*
+ * These are 16-bit segment symbols when compiling 16-bit code.
+ */
+        [S_SEG] =
+        "^real_mode_seg$",
+
+/*
+ * These are offsets belonging to segments, as opposed to linear addresses,
+ * when compiling 16-bit code.
+ */
+        [S_LIN] =
+        "^pa_",
+};
+
+static const char * const *sym_regex;
+
+static regex_t sym_regex_c[S_NSYMTYPES];
+static int is_reloc(enum symtype type, const char *sym_name)
 {
-        return !regexec(&rel_sym_regex_c, sym_name, 0, NULL, 0);
+        return sym_regex[type] &&
+                !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
 }
 
-static void regex_init(void)
+static void regex_init(int use_real_mode)
 {
         char errbuf[128];
         int err;
-        
-        err = regcomp(&abs_sym_regex_c, abs_sym_regex,
-                      REG_EXTENDED|REG_NOSUB);
-        if (err) {
-                regerror(err, &abs_sym_regex_c, errbuf, sizeof errbuf);
-                die("%s", errbuf);
-        }
+        int i;
+
+        if (use_real_mode)
+                sym_regex = sym_regex_realmode;
+        else
+                sym_regex = sym_regex_kernel;
 
-        err = regcomp(&rel_sym_regex_c, rel_sym_regex,
-                      REG_EXTENDED|REG_NOSUB);
-        if (err) {
-                regerror(err, &rel_sym_regex_c, errbuf, sizeof errbuf);
-                die("%s", errbuf);
+        for (i = 0; i < S_NSYMTYPES; i++) {
+                if (!sym_regex[i])
+                        continue;
+
+                err = regcomp(&sym_regex_c[i], sym_regex[i],
+                              REG_EXTENDED|REG_NOSUB);
+
+                if (err) {
+                        regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
+                        die("%s", errbuf);
+                }
         }
 }
 
@@ -154,6 +190,10 @@ static const char *rel_type(unsigned type)
                 REL_TYPE(R_386_RELATIVE),
                 REL_TYPE(R_386_GOTOFF),
                 REL_TYPE(R_386_GOTPC),
+                REL_TYPE(R_386_8),
+                REL_TYPE(R_386_PC8),
+                REL_TYPE(R_386_16),
+                REL_TYPE(R_386_PC16),
 #undef REL_TYPE
         };
         const char *name = "unknown type rel type name";
@@ -189,7 +229,7 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
                 name = sym_strtab + sym->st_name;
         }
         else {
-                name = sec_name(secs[sym->st_shndx].shdr.sh_name);
+                name = sec_name(sym->st_shndx);
         }
         return name;
 }
@@ -472,7 +512,7 @@ static void print_absolute_relocs(void)
                          * Before warning check if this absolute symbol
                          * relocation is harmless.
                          */
-                        if (is_abs_reloc(name) || is_rel_reloc(name))
+                        if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
                                 continue;
 
                         if (!printed) {
@@ -496,7 +536,8 @@ static void print_absolute_relocs(void)
                 printf("\n");
 }
 
-static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
+static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
+                        int use_real_mode)
 {
         int i;
         /* Walk through the relocations */
@@ -521,30 +562,67 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
                         Elf32_Rel *rel;
                         Elf32_Sym *sym;
                         unsigned r_type;
+                        const char *symname;
+                        int shn_abs;
+
                         rel = &sec->reltab[j];
                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
                         r_type = ELF32_R_TYPE(rel->r_info);
-                        /* Don't visit relocations to absolute symbols */
-                        if (sym->st_shndx == SHN_ABS &&
-                            !is_rel_reloc(sym_name(sym_strtab, sym))) {
-                                continue;
-                        }
+
+                        shn_abs = sym->st_shndx == SHN_ABS;
+
                         switch (r_type) {
                         case R_386_NONE:
                         case R_386_PC32:
+                        case R_386_PC16:
+                        case R_386_PC8:
                                 /*
                                  * NONE can be ignored and and PC relative
                                  * relocations don't need to be adjusted.
                                  */
                                 break;
+
+                        case R_386_16:
+                                symname = sym_name(sym_strtab, sym);
+                                if (!use_real_mode)
+                                        goto bad;
+                                if (shn_abs) {
+                                        if (is_reloc(S_ABS, symname))
+                                                break;
+                                        else if (!is_reloc(S_SEG, symname))
+                                                goto bad;
+                                } else {
+                                        if (is_reloc(S_LIN, symname))
+                                                goto bad;
+                                        else
+                                                break;
+                                }
+                                visit(rel, sym);
+                                break;
+
                         case R_386_32:
-                                /* Visit relocations that need to be adjusted */
+                                symname = sym_name(sym_strtab, sym);
+                                if (shn_abs) {
+                                        if (is_reloc(S_ABS, symname))
+                                                break;
+                                        else if (!is_reloc(S_REL, symname))
+                                                goto bad;
+                                } else {
+                                        if (use_real_mode &&
+                                            !is_reloc(S_LIN, symname))
+                                                break;
+                                }
                                 visit(rel, sym);
                                 break;
                         default:
                                 die("Unsupported relocation type: %s (%d)\n",
                                     rel_type(r_type), r_type);
                                 break;
+                        bad:
+                                symname = sym_name(sym_strtab, sym);
+                                die("Invalid %s %s relocation: %s\n",
+                                    shn_abs ? "absolute" : "relative",
+                                    rel_type(r_type), symname);
                         }
                 }
         }
@@ -552,13 +630,19 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
 
 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 {
-        reloc_count += 1;
+        if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+                reloc16_count++;
+        else
+                reloc_count++;
 }
 
 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 {
         /* Remember the address that needs to be adjusted. */
-        relocs[reloc_idx++] = rel->r_offset;
+        if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+                relocs16[reloc16_idx++] = rel->r_offset;
+        else
+                relocs[reloc_idx++] = rel->r_offset;
 }
 
 static int cmp_relocs(const void *va, const void *vb)
@@ -568,23 +652,41 @@ static int cmp_relocs(const void *va, const void *vb)
         return (*a == *b)? 0 : (*a > *b)? 1 : -1;
 }
 
-static void emit_relocs(int as_text)
+static int write32(unsigned int v, FILE *f)
+{
+        unsigned char buf[4];
+
+        put_unaligned_le32(v, buf);
+        return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
+}
+
+static void emit_relocs(int as_text, int use_real_mode)
 {
         int i;
         /* Count how many relocations I have and allocate space for them. */
         reloc_count = 0;
-        walk_relocs(count_reloc);
+        walk_relocs(count_reloc, use_real_mode);
         relocs = malloc(reloc_count * sizeof(relocs[0]));
         if (!relocs) {
                 die("malloc of %d entries for relocs failed\n",
                         reloc_count);
         }
+
+        relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
+        if (!relocs16) {
+                die("malloc of %d entries for relocs16 failed\n",
+                        reloc16_count);
+        }
         /* Collect up the relocations */
         reloc_idx = 0;
-        walk_relocs(collect_reloc);
+        walk_relocs(collect_reloc, use_real_mode);
+
+        if (reloc16_count && !use_real_mode)
+                die("Segment relocations found but --realmode not specified\n");
 
         /* Order the relocations for more efficient processing */
         qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
+        qsort(relocs16, reloc16_count, sizeof(relocs16[0]), cmp_relocs);
 
         /* Print the relocations */
         if (as_text) {
@@ -593,58 +695,83 @@ static void emit_relocs(int as_text)
                  */
                 printf(".section \".data.reloc\",\"a\"\n");
                 printf(".balign 4\n");
-                for (i = 0; i < reloc_count; i++) {
-                        printf("\t .long 0x%08lx\n", relocs[i]);
+                if (use_real_mode) {
+                        printf("\t.long %lu\n", reloc16_count);
+                        for (i = 0; i < reloc16_count; i++)
+                                printf("\t.long 0x%08lx\n", relocs16[i]);
+                        printf("\t.long %lu\n", reloc_count);
+                        for (i = 0; i < reloc_count; i++) {
+                                printf("\t.long 0x%08lx\n", relocs[i]);
+                        }
+                } else {
+                        /* Print a stop */
+                        printf("\t.long 0x%08lx\n", (unsigned long)0);
+                        for (i = 0; i < reloc_count; i++) {
+                                printf("\t.long 0x%08lx\n", relocs[i]);
+                        }
                 }
+
                 printf("\n");
         }
         else {
-                unsigned char buf[4];
-                /* Print a stop */
-                fwrite("\0\0\0\0", 4, 1, stdout);
-                /* Now print each relocation */
-                for (i = 0; i < reloc_count; i++) {
-                        put_unaligned_le32(relocs[i], buf);
-                        fwrite(buf, 4, 1, stdout);
+                if (use_real_mode) {
+                        write32(reloc16_count, stdout);
+                        for (i = 0; i < reloc16_count; i++)
+                                write32(relocs16[i], stdout);
+                        write32(reloc_count, stdout);
+
+                        /* Now print each relocation */
+                        for (i = 0; i < reloc_count; i++)
+                                write32(relocs[i], stdout);
+                } else {
+                        /* Print a stop */
+                        write32(0, stdout);
+
+                        /* Now print each relocation */
+                        for (i = 0; i < reloc_count; i++) {
+                                write32(relocs[i], stdout);
+                        }
                 }
         }
 }
 
 static void usage(void)
 {
-        die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
+        die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
 }
 
 int main(int argc, char **argv)
 {
         int show_absolute_syms, show_absolute_relocs;
-        int as_text;
+        int as_text, use_real_mode;
         const char *fname;
         FILE *fp;
         int i;
 
-        regex_init();
-
         show_absolute_syms = 0;
         show_absolute_relocs = 0;
         as_text = 0;
+        use_real_mode = 0;
         fname = NULL;
         for (i = 1; i < argc; i++) {
                 char *arg = argv[i];
                 if (*arg == '-') {
-                        if (strcmp(argv[1], "--abs-syms") == 0) {
+                        if (strcmp(arg, "--abs-syms") == 0) {
                                 show_absolute_syms = 1;
                                 continue;
                         }
-
-                        if (strcmp(argv[1], "--abs-relocs") == 0) {
+                        if (strcmp(arg, "--abs-relocs") == 0) {
                                 show_absolute_relocs = 1;
                                 continue;
                         }
-                        else if (strcmp(argv[1], "--text") == 0) {
+                        if (strcmp(arg, "--text") == 0) {
                                 as_text = 1;
                                 continue;
                         }
+                        if (strcmp(arg, "--realmode") == 0) {
+                                use_real_mode = 1;
+                                continue;
+                        }
                 }
                 else if (!fname) {
                         fname = arg;
@@ -655,6 +782,7 @@ int main(int argc, char **argv)
         if (!fname) {
                 usage();
         }
+        regex_init(use_real_mode);
         fp = fopen(fname, "r");
         if (!fp) {
                 die("Cannot open %s: %s\n",
@@ -673,6 +801,6 @@ int main(int argc, char **argv)
                 print_absolute_relocs();
                 return 0;
         }
-        emit_relocs(as_text);
+        emit_relocs(as_text, use_real_mode);
         return 0;
 }
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index a8f8844b8d32..95dccce8e979 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -63,6 +63,7 @@
 #include <asm/stackprotector.h>
 #include <asm/hypervisor.h>
 #include <asm/mwait.h>
+#include <asm/pci_x86.h>
 
 #ifdef CONFIG_ACPI
 #include <linux/acpi.h>
@@ -809,9 +810,40 @@ static void xen_io_delay(void)
 }
 
 #ifdef CONFIG_X86_LOCAL_APIC
+static unsigned long xen_set_apic_id(unsigned int x)
+{
+        WARN_ON(1);
+        return x;
+}
+static unsigned int xen_get_apic_id(unsigned long x)
+{
+        return ((x)>>24) & 0xFFu;
+}
 static u32 xen_apic_read(u32 reg)
 {
-        return 0;
+        struct xen_platform_op op = {
+                .cmd = XENPF_get_cpuinfo,
+                .interface_version = XENPF_INTERFACE_VERSION,
+                .u.pcpu_info.xen_cpuid = 0,
+        };
+        int ret = 0;
+
+        /* Shouldn't need this as APIC is turned off for PV, and we only
+         * get called on the bootup processor. But just in case. */
+        if (!xen_initial_domain() || smp_processor_id())
+                return 0;
+
+        if (reg == APIC_LVR)
+                return 0x10;
+
+        if (reg != APIC_ID)
+                return 0;
+
+        ret = HYPERVISOR_dom0_op(&op);
+        if (ret)
+                return 0;
+
+        return op.u.pcpu_info.apic_id << 24;
 }
 
 static void xen_apic_write(u32 reg, u32 val)
@@ -849,6 +881,8 @@ static void set_xen_basic_apic_ops(void)
         apic->icr_write = xen_apic_icr_write;
         apic->wait_icr_idle = xen_apic_wait_icr_idle;
         apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
+        apic->set_apic_id = xen_set_apic_id;
+        apic->get_apic_id = xen_get_apic_id;
 }
 
 #endif
@@ -1365,8 +1399,10 @@ asmlinkage void __init xen_start_kernel(void)
                 /* Make sure ACS will be enabled */
                 pci_request_acs();
         }
-                
-
+#ifdef CONFIG_PCI
+        /* PCI BIOS service won't work from a PV guest. */
+        pci_probe &= ~PCI_PROBE_BIOS;
+#endif
         xen_raw_console_write("about to get started...\n");
 
         xen_setup_runstate_info(0);
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index b8e279479a6b..69f5857660ac 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -353,8 +353,13 @@ static pteval_t pte_mfn_to_pfn(pteval_t val)
 {
         if (val & _PAGE_PRESENT) {
                 unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+                unsigned long pfn = mfn_to_pfn(mfn);
+
                 pteval_t flags = val & PTE_FLAGS_MASK;
-                val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
+                if (unlikely(pfn == ~0))
+                        val = flags & ~_PAGE_PRESENT;
+                else
+                        val = ((pteval_t)pfn << PAGE_SHIFT) | flags;
         }
 
         return val;