5 files changed, 23 insertions, 5 deletions

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)
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 4b33acd8ed4e..0a8a17cd80be 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -274,7 +274,7 @@ static unsigned int cpu_from_evtchn(unsigned int evtchn)
 
 static bool pirq_check_eoi_map(unsigned irq)
 {
-        return test_bit(irq, pirq_eoi_map);
+        return test_bit(pirq_from_irq(irq), pirq_eoi_map);
 }
 
 static bool pirq_needs_eoi_flag(unsigned irq)
diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
index 174b5653cd8a..0b48579a9cd6 100644
--- a/drivers/xen/xen-acpi-processor.c
+++ b/drivers/xen/xen-acpi-processor.c
@@ -128,7 +128,10 @@ static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
                         pr_debug("     C%d: %s %d uS\n",
                                  cx->type, cx->desc, (u32)cx->latency);
                 }
-        } else
+        } else if (ret != -EINVAL)
+                /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
+                 * table is referencing a non-existing CPU - which can happen
+                 * with broken ACPI tables. */
                 pr_err(DRV_NAME "(CX): Hypervisor error (%d) for ACPI CPU%u\n",
                        ret, _pr->acpi_id);