26 files changed, 135 insertions, 79 deletions

diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index a0559930a180..c85e3ac99bba 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -33,6 +33,9 @@
         __HEAD
 ENTRY(startup_32)
 #ifdef CONFIG_EFI_STUB
+        jmp     preferred_addr
+
+        .balign 0x10
         /*
          * We don't need the return address, so set up the stack so
          * efi_main() can find its arugments.
@@ -41,12 +44,17 @@ ENTRY(startup_32)
 
         call    efi_main
         cmpl    $0, %eax
-        je      preferred_addr
         movl    %eax, %esi
-        call    1f
+        jne     2f
 1:
+        /* EFI init failed, so hang. */
+        hlt
+        jmp     1b
+2:
+        call    3f
+3:
         popl    %eax
-        subl    $1b, %eax
+        subl    $3b, %eax
         subl    BP_pref_address(%esi), %eax
         add     BP_code32_start(%esi), %eax
         leal    preferred_addr(%eax), %eax
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 558d76ce23bc..87e03a13d8e3 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -200,18 +200,28 @@ ENTRY(startup_64)
          * entire text+data+bss and hopefully all of memory.
          */
 #ifdef CONFIG_EFI_STUB
-        pushq   %rsi
+        /*
+         * The entry point for the PE/COFF executable is 0x210, so only
+         * legacy boot loaders will execute this jmp.
+         */
+        jmp     preferred_addr
+
+        .org 0x210
         mov     %rcx, %rdi
         mov     %rdx, %rsi
         call    efi_main
-        popq    %rsi
-        cmpq    $0,%rax
-        je      preferred_addr
         movq    %rax,%rsi
-        call    1f
+        cmpq    $0,%rax
+        jne     2f
 1:
+        /* EFI init failed, so hang. */
+        hlt
+        jmp     1b
+2:
+        call    3f
+3:
         popq    %rax
-        subq    $1b, %rax
+        subq    $3b, %rax
         subq    BP_pref_address(%rsi), %rax
         add     BP_code32_start(%esi), %eax
         leaq    preferred_addr(%rax), %rax
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
index ed549767a231..24443a332083 100644
--- a/arch/x86/boot/tools/build.c
+++ b/arch/x86/boot/tools/build.c
@@ -205,8 +205,13 @@ int main(int argc, char ** argv)
         put_unaligned_le32(file_sz, &buf[pe_header + 0x50]);
 
 #ifdef CONFIG_X86_32
-        /* Address of entry point */
-        put_unaligned_le32(i, &buf[pe_header + 0x28]);
+        /*
+         * Address of entry point.
+         *
+         * The EFI stub entry point is +16 bytes from the start of
+         * the .text section.
+         */
+        put_unaligned_le32(i + 16, &buf[pe_header + 0x28]);
 
         /* .text size */
         put_unaligned_le32(file_sz, &buf[pe_header + 0xb0]);
@@ -217,9 +222,11 @@ int main(int argc, char ** argv)
         /*
          * Address of entry point. startup_32 is at the beginning and
          * the 64-bit entry point (startup_64) is always 512 bytes
-         * after.
+         * after. The EFI stub entry point is 16 bytes after that, as
+         * the first instruction allows legacy loaders to jump over
+         * the EFI stub initialisation
          */
-        put_unaligned_le32(i + 512, &buf[pe_header + 0x28]);
+        put_unaligned_le32(i + 528, &buf[pe_header + 0x28]);
 
         /* .text size */
         put_unaligned_le32(file_sz, &buf[pe_header + 0xc0]);
diff --git a/arch/x86/include/asm/posix_types.h b/arch/x86/include/asm/posix_types.h
index 3427b7798dbc..7ef7c3020e5c 100644
--- a/arch/x86/include/asm/posix_types.h
+++ b/arch/x86/include/asm/posix_types.h
@@ -7,9 +7,9 @@
 #else
 # ifdef __i386__
 #  include "posix_types_32.h"
-# elif defined(__LP64__)
-#  include "posix_types_64.h"
-# else
+# elif defined(__ILP32__)
 #  include "posix_types_x32.h"
+# else
+#  include "posix_types_64.h"
 # endif
 #endif
diff --git a/arch/x86/include/asm/sigcontext.h b/arch/x86/include/asm/sigcontext.h
index 4a085383af27..5ca71c065eef 100644
--- a/arch/x86/include/asm/sigcontext.h
+++ b/arch/x86/include/asm/sigcontext.h
@@ -257,7 +257,7 @@ struct sigcontext {
         __u64 oldmask;
         __u64 cr2;
         struct _fpstate __user *fpstate;        /* zero when no FPU context */
-#ifndef __LP64__
+#ifdef __ILP32__
         __u32 __fpstate_pad;
 #endif
         __u64 reserved1[8];
diff --git a/arch/x86/include/asm/siginfo.h b/arch/x86/include/asm/siginfo.h
index fc1aa5535646..34c47b3341c0 100644
--- a/arch/x86/include/asm/siginfo.h
+++ b/arch/x86/include/asm/siginfo.h
@@ -2,7 +2,13 @@
 #define _ASM_X86_SIGINFO_H
 
 #ifdef __x86_64__
-# define __ARCH_SI_PREAMBLE_SIZE        (4 * sizeof(int))
+# ifdef __ILP32__ /* x32 */
+typedef long long __kernel_si_clock_t __attribute__((aligned(4)));
+#  define __ARCH_SI_CLOCK_T             __kernel_si_clock_t
+#  define __ARCH_SI_ATTRIBUTES          __attribute__((aligned(8)))
+# else /* x86-64 */
+#  define __ARCH_SI_PREAMBLE_SIZE       (4 * sizeof(int))
+# endif
 #endif
 
 #include <asm-generic/siginfo.h>
diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index 37cdc9d99bb1..4437001d8e3d 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -63,10 +63,10 @@
 #else
 # ifdef __i386__
 #  include <asm/unistd_32.h>
-# elif defined(__LP64__)
-#  include <asm/unistd_64.h>
-# else
+# elif defined(__ILP32__)
 #  include <asm/unistd_x32.h>
+# else
+#  include <asm/unistd_64.h>
 # endif
 #endif
 
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index baaca8defec8..764b66a4cf89 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -195,6 +195,5 @@ extern struct x86_msi_ops x86_msi;
 
 extern void x86_init_noop(void);
 extern void x86_init_uint_noop(unsigned int unused);
-extern void x86_default_fixup_cpu_id(struct cpuinfo_x86 *c, int node);
 
 #endif
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 103b6ab368d3..146a49c763a4 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -24,6 +24,10 @@ unsigned long acpi_realmode_flags;
 static char temp_stack[4096];
 #endif
 
+asmlinkage void acpi_enter_s3(void)
+{
+        acpi_enter_sleep_state(3, wake_sleep_flags);
+}
 /**
  * acpi_suspend_lowlevel - save kernel state
  *
diff --git a/arch/x86/kernel/acpi/sleep.h b/arch/x86/kernel/acpi/sleep.h
index 416d4be13fef..d68677a2a010 100644
--- a/arch/x86/kernel/acpi/sleep.h
+++ b/arch/x86/kernel/acpi/sleep.h
@@ -3,12 +3,16 @@
  */
 
 #include <asm/trampoline.h>
+#include <linux/linkage.h>
 
 extern unsigned long saved_video_mode;
 extern long saved_magic;
 
 extern int wakeup_pmode_return;
 
+extern u8 wake_sleep_flags;
+extern asmlinkage void acpi_enter_s3(void);
+
 extern unsigned long acpi_copy_wakeup_routine(unsigned long);
 extern void wakeup_long64(void);
 
diff --git a/arch/x86/kernel/acpi/wakeup_32.S b/arch/x86/kernel/acpi/wakeup_32.S
index 13ab720573e3..72610839f03b 100644
--- a/arch/x86/kernel/acpi/wakeup_32.S
+++ b/arch/x86/kernel/acpi/wakeup_32.S
@@ -74,9 +74,7 @@ restore_registers:
 ENTRY(do_suspend_lowlevel)
         call    save_processor_state
         call    save_registers
-        pushl   $3
-        call    acpi_enter_sleep_state
-        addl    $4, %esp
+        call    acpi_enter_s3
 
 #       In case of S3 failure, we'll emerge here.  Jump
 #       to ret_point to recover
diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index 8ea5164cbd04..014d1d28c397 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -71,9 +71,7 @@ ENTRY(do_suspend_lowlevel)
         movq    %rsi, saved_rsi
 
         addq    $8, %rsp
-        movl    $3, %edi
-        xorl    %eax, %eax
-        call    acpi_enter_sleep_state
+        call    acpi_enter_s3
         /* in case something went wrong, restore the machine status and go on */
         jmp     resume_point
 
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 11544d8f1e97..edc24480469f 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1637,9 +1637,11 @@ static int __init apic_verify(void)
         mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
 
         /* The BIOS may have set up the APIC at some other address */
-        rdmsr(MSR_IA32_APICBASE, l, h);
-        if (l & MSR_IA32_APICBASE_ENABLE)
-                mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
+        if (boot_cpu_data.x86 >= 6) {
+                rdmsr(MSR_IA32_APICBASE, l, h);
+                if (l & MSR_IA32_APICBASE_ENABLE)
+                        mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
+        }
 
         pr_info("Found and enabled local APIC!\n");
         return 0;
@@ -1657,13 +1659,15 @@ int __init apic_force_enable(unsigned long addr)
          * MSR. This can only be done in software for Intel P6 or later
          * and AMD K7 (Model > 1) or later.
          */
-        rdmsr(MSR_IA32_APICBASE, l, h);
-        if (!(l & MSR_IA32_APICBASE_ENABLE)) {
-                pr_info("Local APIC disabled by BIOS -- reenabling.\n");
-                l &= ~MSR_IA32_APICBASE_BASE;
-                l |= MSR_IA32_APICBASE_ENABLE | addr;
-                wrmsr(MSR_IA32_APICBASE, l, h);
-                enabled_via_apicbase = 1;
+        if (boot_cpu_data.x86 >= 6) {
+                rdmsr(MSR_IA32_APICBASE, l, h);
+                if (!(l & MSR_IA32_APICBASE_ENABLE)) {
+                        pr_info("Local APIC disabled by BIOS -- reenabling.\n");
+                        l &= ~MSR_IA32_APICBASE_BASE;
+                        l |= MSR_IA32_APICBASE_ENABLE | addr;
+                        wrmsr(MSR_IA32_APICBASE, l, h);
+                        enabled_via_apicbase = 1;
+                }
         }
         return apic_verify();
 }
@@ -2209,10 +2213,12 @@ static void lapic_resume(void)
                  * FIXME! This will be wrong if we ever support suspend on
                  * SMP! We'll need to do this as part of the CPU restore!
                  */
-                rdmsr(MSR_IA32_APICBASE, l, h);
-                l &= ~MSR_IA32_APICBASE_BASE;
-                l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
-                wrmsr(MSR_IA32_APICBASE, l, h);
+                if (boot_cpu_data.x86 >= 6) {
+                        rdmsr(MSR_IA32_APICBASE, l, h);
+                        l &= ~MSR_IA32_APICBASE_BASE;
+                        l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
+                        wrmsr(MSR_IA32_APICBASE, l, h);
+                }
         }
 
         maxlvt = lapic_get_maxlvt();
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 899803e03214..23e75422e013 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -207,8 +207,11 @@ static void __init map_csrs(void)
 
 static void fixup_cpu_id(struct cpuinfo_x86 *c, int node)
 {
-        c->phys_proc_id = node;
-        per_cpu(cpu_llc_id, smp_processor_id()) = node;
+
+        if (c->phys_proc_id != node) {
+                c->phys_proc_id = node;
+                per_cpu(cpu_llc_id, smp_processor_id()) = node;
+        }
 }
 
 static int __init numachip_system_init(void)
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index 8a778db45e3a..991e315f4227 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -24,6 +24,12 @@ static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
         if (x2apic_phys)
                 return x2apic_enabled();
+        else if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) &&
+                (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) &&
+                x2apic_enabled()) {
+                printk(KERN_DEBUG "System requires x2apic physical mode\n");
+                return 1;
+        }
         else
                 return 0;
 }
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 0a44b90602b0..1c67ca100e4c 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -26,7 +26,8 @@
  *      contact AMD for precise details and a CPU swap.
  *
  *      See     http://www.multimania.com/poulot/k6bug.html
- *              http://www.amd.com/K6/k6docs/revgd.html
+ *      and     section 2.6.2 of "AMD-K6 Processor Revision Guide - Model 6"
+ *              (Publication # 21266  Issue Date: August 1998)
  *
  *      The following test is erm.. interesting. AMD neglected to up
  *      the chip setting when fixing the bug but they also tweaked some
@@ -94,7 +95,6 @@ static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
                                 "system stability may be impaired when more than 32 MB are used.\n");
                 else
                         printk(KERN_CONT "probably OK (after B9730xxxx).\n");
-                printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
         }
 
         /* K6 with old style WHCR */
@@ -353,10 +353,11 @@ static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
                 node = per_cpu(cpu_llc_id, cpu);
 
         /*
-         * If core numbers are inconsistent, it's likely a multi-fabric platform,
-         * so invoke platform-specific handler
+         * On multi-fabric platform (e.g. Numascale NumaChip) a
+         * platform-specific handler needs to be called to fixup some
+         * IDs of the CPU.
          */
-        if (c->phys_proc_id != node)
+        if (x86_cpuinit.fixup_cpu_id)
                 x86_cpuinit.fixup_cpu_id(c, node);
 
         if (!node_online(node)) {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 67e258362a3d..cf79302198a6 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1163,15 +1163,6 @@ static void dbg_restore_debug_regs(void)
 #endif /* ! CONFIG_KGDB */
 
 /*
- * Prints an error where the NUMA and configured core-number mismatch and the
- * platform didn't override this to fix it up
- */
-void __cpuinit x86_default_fixup_cpu_id(struct cpuinfo_x86 *c, int node)
-{
-        pr_err("NUMA core number %d differs from configured core number %d\n", node, c->phys_proc_id);
-}
-
-/*
  * cpu_init() initializes state that is per-CPU. Some data is already
  * initialized (naturally) in the bootstrap process, such as the GDT
  * and IDT. We reload them nevertheless, this function acts as a
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index 73d08ed98a64..b8f3653dddbc 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -433,14 +433,14 @@ int amd_set_l3_disable_slot(struct amd_northbridge *nb, int cpu, unsigned slot,
         /*  check if @slot is already used or the index is already disabled */
         ret = amd_get_l3_disable_slot(nb, slot);
         if (ret >= 0)
-                return -EINVAL;
+                return -EEXIST;
 
         if (index > nb->l3_cache.indices)
                 return -EINVAL;
 
         /* check whether the other slot has disabled the same index already */
         if (index == amd_get_l3_disable_slot(nb, !slot))
-                return -EINVAL;
+                return -EEXIST;
 
         amd_l3_disable_index(nb, cpu, slot, index);
 
@@ -468,8 +468,8 @@ static ssize_t store_cache_disable(struct _cpuid4_info *this_leaf,
         err = amd_set_l3_disable_slot(this_leaf->base.nb, cpu, slot, val);
         if (err) {
                 if (err == -EEXIST)
-                        printk(KERN_WARNING "L3 disable slot %d in use!\n",
-                                            slot);
+                        pr_warning("L3 slot %d in use/index already disabled!\n",
+                                   slot);
                 return err;
         }
         return count;
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 7734bcbb5a3a..2d6e6498c176 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -235,6 +235,7 @@ int init_fpu(struct task_struct *tsk)
         if (tsk_used_math(tsk)) {
                 if (HAVE_HWFP && tsk == current)
                         unlazy_fpu(tsk);
+                tsk->thread.fpu.last_cpu = ~0;
                 return 0;
         }
 
diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index 73465aab28f8..8a2ce8fd41c0 100644
--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -82,11 +82,6 @@ static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
 {
         struct cpuinfo_x86 *c = &cpu_data(cpu);
 
-        if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
-                pr_warning("CPU%d: family %d not supported\n", cpu, c->x86);
-                return -1;
-        }
-
         csig->rev = c->microcode;
         pr_info("CPU%d: patch_level=0x%08x\n", cpu, csig->rev);
 
@@ -380,6 +375,13 @@ static struct microcode_ops microcode_amd_ops = {
 
 struct microcode_ops * __init init_amd_microcode(void)
 {
+        struct cpuinfo_x86 *c = &cpu_data(0);
+
+        if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
+                pr_warning("AMD CPU family 0x%x not supported\n", c->x86);
+                return NULL;
+        }
+
         patch = (void *)get_zeroed_page(GFP_KERNEL);
         if (!patch)
                 return NULL;
diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index 87a0f8688301..c9bda6d6035c 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -419,10 +419,8 @@ static int mc_device_add(struct device *dev, struct subsys_interface *sif)
         if (err)
                 return err;
 
-        if (microcode_init_cpu(cpu) == UCODE_ERROR) {
-                sysfs_remove_group(&dev->kobj, &mc_attr_group);
+        if (microcode_init_cpu(cpu) == UCODE_ERROR)
                 return -EINVAL;
-        }
 
         return err;
 }
@@ -528,11 +526,11 @@ static int __init microcode_init(void)
                 microcode_ops = init_intel_microcode();
         else if (c->x86_vendor == X86_VENDOR_AMD)
                 microcode_ops = init_amd_microcode();
-
-        if (!microcode_ops) {
+        else
                 pr_err("no support for this CPU vendor\n");
+
+        if (!microcode_ops)
                 return -ENODEV;
-        }
 
         microcode_pdev = platform_device_register_simple("microcode", -1,
                                                          NULL, 0);
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index e9f265fd79ae..9cf71d0b2d37 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -93,7 +93,6 @@ struct x86_init_ops x86_init __initdata = {
 struct x86_cpuinit_ops x86_cpuinit __cpuinitdata = {
         .early_percpu_clock_init        = x86_init_noop,
         .setup_percpu_clockev           = setup_secondary_APIC_clock,
-        .fixup_cpu_id                   = x86_default_fixup_cpu_id,
 };
 
 static void default_nmi_init(void) { };
diff --git a/arch/x86/platform/mrst/mrst.c b/arch/x86/platform/mrst/mrst.c
index e0a37233c0af..e31bcd8f2eee 100644
--- a/arch/x86/platform/mrst/mrst.c
+++ b/arch/x86/platform/mrst/mrst.c
@@ -805,7 +805,7 @@ void intel_scu_devices_create(void)
                 } else
                         i2c_register_board_info(i2c_bus[i], i2c_devs[i], 1);
         }
-        intel_scu_notifier_post(SCU_AVAILABLE, 0L);
+        intel_scu_notifier_post(SCU_AVAILABLE, NULL);
 }
 EXPORT_SYMBOL_GPL(intel_scu_devices_create);
 
@@ -814,7 +814,7 @@ void intel_scu_devices_destroy(void)
 {
         int i;
 
-        intel_scu_notifier_post(SCU_DOWN, 0L);
+        intel_scu_notifier_post(SCU_DOWN, NULL);
 
         for (i = 0; i < ipc_next_dev; i++)
                 platform_device_del(ipc_devs[i]);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 4f51bebac02c..a8f8844b8d32 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -261,7 +261,8 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 
 static bool __init xen_check_mwait(void)
 {
-#ifdef CONFIG_ACPI
+#if defined(CONFIG_ACPI) && !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) && \
+        !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
         struct xen_platform_op op = {
                 .cmd                    = XENPF_set_processor_pminfo,
                 .u.set_pminfo.id        = -1,
@@ -349,7 +350,6 @@ static void __init xen_init_cpuid_mask(void)
         /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
         if ((cx & xsave_mask) != xsave_mask)
                 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
-
         if (xen_check_mwait())
                 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
 }
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 5fac6919b957..0503c0c493a9 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -178,6 +178,7 @@ static void __init xen_fill_possible_map(void)
 static void __init xen_filter_cpu_maps(void)
 {
         int i, rc;
+        unsigned int subtract = 0;
 
         if (!xen_initial_domain())
                 return;
@@ -192,8 +193,22 @@ static void __init xen_filter_cpu_maps(void)
                 } else {
                         set_cpu_possible(i, false);
                         set_cpu_present(i, false);
+                        subtract++;
                 }
         }
+#ifdef CONFIG_HOTPLUG_CPU
+        /* This is akin to using 'nr_cpus' on the Linux command line.
+         * Which is OK as when we use 'dom0_max_vcpus=X' we can only
+         * have up to X, while nr_cpu_ids is greater than X. This
+         * normally is not a problem, except when CPU hotplugging
+         * is involved and then there might be more than X CPUs
+         * in the guest - which will not work as there is no
+         * hypercall to expand the max number of VCPUs an already
+         * running guest has. So cap it up to X. */
+        if (subtract)
+                nr_cpu_ids = nr_cpu_ids - subtract;
+#endif
+
 }
 
 static void __init xen_smp_prepare_boot_cpu(void)
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 79d7362ad6d1..3e45aa000718 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -96,7 +96,7 @@ ENTRY(xen_restore_fl_direct)
 
         /* check for unmasked and pending */
         cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
-        jz 1f
+        jnz 1f
 2:      call check_events
 1:
 ENDPATCH(xen_restore_fl_direct)