Merge branch 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen

* 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen:
  xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead.
  xen: x86_32: do not enable iterrupts when returning from exception in interrupt context
  xen: use maximum reservation to limit amount of usable RAM

3 files changed, 34 insertions, 3 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index df118a825f3..c3b8d440873 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 +305,12 @@ 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 (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 e79dbb95482..d4fc6d454f8 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);
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
index 22a2093b586..b040b0e518c 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