Merge tag 'for-linus-4.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Other than fixes and cleanups it contains:

   - support > 32 VCPUs at domain restore

   - support for new sysfs nodes related to Xen

   - some performance tuning for Linux running as Xen guest"

* tag 'for-linus-4.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: allow userspace access during hypercalls
  x86: xen: remove unnecessary variable in xen_foreach_remap_area()
  xen: allocate page for shared info page from low memory
  xen: avoid deadlock in xenbus driver
  xen: add sysfs node for hypervisor build id
  xen: sync include/xen/interface/version.h
  xen: add sysfs node for guest type
  doc,xen: document hypervisor sysfs nodes for xen
  xen/vcpu: Handle xen_vcpu_setup() failure at boot
  xen/vcpu: Handle xen_vcpu_setup() failure in hotplug
  xen/pv: Fix OOPS on restore for a PV, !SMP domain
  xen/pvh*: Support > 32 VCPUs at domain restore
  xen/vcpu: Simplify xen_vcpu related code
  xen-evtchn: Bind dyn evtchn:qemu-dm interrupt to next online VCPU
  xen: avoid type warning in xchg_xen_ulong
  xen: fix HYPERVISOR_dm_op() prototype
  xen: don't print error message in case of missing Xenstore entry
  arm/xen: Adjust one function call together with a variable assignment
  arm/xen: Delete an error message for a failed memory allocation in __set_phys_to_machine_multi()
  arm/xen: Improve a size determination in __set_phys_to_machine_multi()

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 82ac611f2fc1..e7f02eb73727 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -1,4 +1,5 @@
 #include <linux/smp.h>
+#include <linux/cpu.h>
 #include <linux/slab.h>
 #include <linux/cpumask.h>
 #include <linux/percpu.h>
@@ -114,6 +115,36 @@ int xen_smp_intr_init(unsigned int cpu)
 	return rc;
 }
 
+void __init xen_smp_cpus_done(unsigned int max_cpus)
+{
+	int cpu, rc, count = 0;
+
+	if (xen_hvm_domain())
+		native_smp_cpus_done(max_cpus);
+
+	if (xen_have_vcpu_info_placement)
+		return;
+
+	for_each_online_cpu(cpu) {
+		if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
+			continue;
+
+		rc = cpu_down(cpu);
+
+		if (rc == 0) {
+			/*
+			 * Reset vcpu_info so this cpu cannot be onlined again.
+			 */
+			xen_vcpu_info_reset(cpu);
+			count++;
+		} else {
+			pr_warn("%s: failed to bring CPU %d down, error %d\n",
+				__func__, cpu, rc);
+		}
+	}
+	WARN(count, "%s: brought %d CPUs offline\n", __func__, count);
+}
+
 void xen_smp_send_reschedule(int cpu)
 {
 	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);