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-rw-r--r--arch/x86/kernel/apic/apic.c34
-rw-r--r--arch/x86/xen/smp.c15
-rw-r--r--arch/x86/xen/xen-asm.S2
3 files changed, 36 insertions, 15 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index b9338b8..1471695 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1558,9 +1558,11 @@ 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;
@@ -1578,13 +1580,15 @@ 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();
}
@@ -2112,10 +2116,12 @@ 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/xen/smp.c b/arch/x86/xen/smp.c
index d4fc6d4..2843b5e 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -172,6 +172,7 @@ 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;
@@ -186,8 +187,22 @@ 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 79d7362..3e45aa0 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)