5 files changed, 41 insertions, 10 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 20a614275064..3dd53f997b11 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1721,10 +1721,8 @@ void __init xen_setup_machphys_mapping(void)
                 machine_to_phys_nr = MACH2PHYS_NR_ENTRIES;
         }
 #ifdef CONFIG_X86_32
-        if ((machine_to_phys_mapping + machine_to_phys_nr)
-            < machine_to_phys_mapping)
-                machine_to_phys_nr = (unsigned long *)NULL
-                                     - machine_to_phys_mapping;
+        WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1))
+                < machine_to_phys_mapping);
 #endif
 }
 
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index df118a825f39..46d6d21dbdbe 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -184,6 +184,19 @@ static unsigned long __init xen_set_identity(const struct e820entry *list,
                                         PFN_UP(start_pci), PFN_DOWN(last));
         return identity;
 }
+
+static unsigned long __init xen_get_max_pages(void)
+{
+        unsigned long max_pages = MAX_DOMAIN_PAGES;
+        domid_t domid = DOMID_SELF;
+        int ret;
+
+        ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
+        if (ret > 0)
+                max_pages = ret;
+        return min(max_pages, MAX_DOMAIN_PAGES);
+}
+
 /**
  * machine_specific_memory_setup - Hook for machine specific memory setup.
  **/
@@ -292,6 +305,14 @@ char * __init xen_memory_setup(void)
 
         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
+        extra_limit = xen_get_max_pages();
+        if (max_pfn + extra_pages > extra_limit) {
+                if (extra_limit > max_pfn)
+                        extra_pages = extra_limit - max_pfn;
+                else
+                        extra_pages = 0;
+        }
+
         extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
 
         /*
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index e79dbb95482b..041d4fe9dfe4 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -32,6 +32,7 @@
 #include <xen/page.h>
 #include <xen/events.h>
 
+#include <xen/hvc-console.h>
 #include "xen-ops.h"
 #include "mmu.h"
 
@@ -207,6 +208,15 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
         unsigned cpu;
         unsigned int i;
 
+        if (skip_ioapic_setup) {
+                char *m = (max_cpus == 0) ?
+                        "The nosmp parameter is incompatible with Xen; " \
+                        "use Xen dom0_max_vcpus=1 parameter" :
+                        "The noapic parameter is incompatible with Xen";
+
+                xen_raw_printk(m);
+                panic(m);
+        }
         xen_init_lock_cpu(0);
 
         smp_store_cpu_info(0);
@@ -522,7 +532,6 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
         WARN_ON(xen_smp_intr_init(0));
 
         xen_init_lock_cpu(0);
-        xen_init_spinlocks();
 }
 
 static int __cpuinit xen_hvm_cpu_up(unsigned int cpu)
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 5158c505bef9..163b4679556e 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -168,9 +168,10 @@ cycle_t xen_clocksource_read(void)
         struct pvclock_vcpu_time_info *src;
         cycle_t ret;
 
-        src = &get_cpu_var(xen_vcpu)->time;
+        preempt_disable_notrace();
+        src = &__get_cpu_var(xen_vcpu)->time;
         ret = pvclock_clocksource_read(src);
-        put_cpu_var(xen_vcpu);
+        preempt_enable_notrace();
         return ret;
 }
 
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
index 22a2093b5862..b040b0e518ca 100644
--- a/arch/x86/xen/xen-asm_32.S
+++ b/arch/x86/xen/xen-asm_32.S
@@ -113,11 +113,13 @@ xen_iret_start_crit:
 
         /*
          * If there's something pending, mask events again so we can
-         * jump back into xen_hypervisor_callback
+         * jump back into xen_hypervisor_callback. Otherwise do not
+         * touch XEN_vcpu_info_mask.
          */
-        sete XEN_vcpu_info_mask(%eax)
+        jne 1f
+        movb $1, XEN_vcpu_info_mask(%eax)
 
-        popl %eax
+1:      popl %eax
 
         /*
          * From this point on the registers are restored and the stack