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()

13 files changed, 259 insertions, 147 deletions

diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h
index 71e473d..620dc75 100644
--- a/arch/arm/include/asm/xen/events.h
+++ b/arch/arm/include/asm/xen/events.h
@@ -16,7 +16,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
 	return raw_irqs_disabled_flags(regs->ARM_cpsr);
 }
 
-#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((ptr),	\
+#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((long long*)(ptr),\
 							    atomic64_t,	\
 							    counter), (val))
 
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index 0ed01f2..e71eefa 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -144,17 +144,17 @@ bool __set_phys_to_machine_multi(unsigned long pfn,
 		return true;
 	}
 
-	p2m_entry = kzalloc(sizeof(struct xen_p2m_entry), GFP_NOWAIT);
-	if (!p2m_entry) {
-		pr_warn("cannot allocate xen_p2m_entry\n");
+	p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT);
+	if (!p2m_entry)
 		return false;
-	}
+
 	p2m_entry->pfn = pfn;
 	p2m_entry->nr_pages = nr_pages;
 	p2m_entry->mfn = mfn;
 
 	write_lock_irqsave(&p2m_lock, irqflags);
-	if ((rc = xen_add_phys_to_mach_entry(p2m_entry)) < 0) {
+	rc = xen_add_phys_to_mach_entry(p2m_entry);
+	if (rc < 0) {
 		write_unlock_irqrestore(&p2m_lock, irqflags);
 		return false;
 	}
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index f6d20f6..11071fc 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -43,6 +43,7 @@
 
 #include <asm/page.h>
 #include <asm/pgtable.h>
+#include <asm/smap.h>
 
 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
@@ -50,6 +51,8 @@
 #include <xen/interface/platform.h>
 #include <xen/interface/xen-mca.h>
 
+struct xen_dm_op_buf;
+
 /*
  * The hypercall asms have to meet several constraints:
  * - Work on 32- and 64-bit.
@@ -214,10 +217,12 @@ privcmd_call(unsigned call,
 	__HYPERCALL_DECLS;
 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);
 
+	stac();
 	asm volatile("call *%[call]"
 		     : __HYPERCALL_5PARAM
 		     : [call] "a" (&hypercall_page[call])
 		     : __HYPERCALL_CLOBBER5);
+	clac();
 
 	return (long)__res;
 }
@@ -474,9 +479,13 @@ HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
 
 static inline int
 HYPERVISOR_dm_op(
-	domid_t dom, unsigned int nr_bufs, void *bufs)
+	domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
 {
-	return _hypercall3(int, dm_op, dom, nr_bufs, bufs);
+	int ret;
+	stac();
+	ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
+	clac();
+	return ret;
 }
 
 static inline void
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index a5ffcbb..0e7ef69 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -106,15 +106,83 @@ int xen_cpuhp_setup(int (*cpu_up_prepare_cb)(unsigned int),
 	return rc >= 0 ? 0 : rc;
 }
 
-static void clamp_max_cpus(void)
+static int xen_vcpu_setup_restore(int cpu)
 {
-#ifdef CONFIG_SMP
-	if (setup_max_cpus > MAX_VIRT_CPUS)
-		setup_max_cpus = MAX_VIRT_CPUS;
-#endif
+	int rc = 0;
+
+	/* Any per_cpu(xen_vcpu) is stale, so reset it */
+	xen_vcpu_info_reset(cpu);
+
+	/*
+	 * For PVH and PVHVM, setup online VCPUs only. The rest will
+	 * be handled by hotplug.
+	 */
+	if (xen_pv_domain() ||
+	    (xen_hvm_domain() && cpu_online(cpu))) {
+		rc = xen_vcpu_setup(cpu);
+	}
+
+	return rc;
+}
+
+/*
+ * On restore, set the vcpu placement up again.
+ * If it fails, then we're in a bad state, since
+ * we can't back out from using it...
+ */
+void xen_vcpu_restore(void)
+{
+	int cpu, rc;
+
+	for_each_possible_cpu(cpu) {
+		bool other_cpu = (cpu != smp_processor_id());
+		bool is_up;
+
+		if (xen_vcpu_nr(cpu) == XEN_VCPU_ID_INVALID)
+			continue;
+
+		/* Only Xen 4.5 and higher support this. */
+		is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up,
+					   xen_vcpu_nr(cpu), NULL) > 0;
+
+		if (other_cpu && is_up &&
+		    HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
+			BUG();
+
+		if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
+			xen_setup_runstate_info(cpu);
+
+		rc = xen_vcpu_setup_restore(cpu);
+		if (rc)
+			pr_emerg_once("vcpu restore failed for cpu=%d err=%d. "
+					"System will hang.\n", cpu, rc);
+		/*
+		 * In case xen_vcpu_setup_restore() fails, do not bring up the
+		 * VCPU. This helps us avoid the resulting OOPS when the VCPU
+		 * accesses pvclock_vcpu_time via xen_vcpu (which is NULL.)
+		 * Note that this does not improve the situation much -- now the
+		 * VM hangs instead of OOPSing -- with the VCPUs that did not
+		 * fail, spinning in stop_machine(), waiting for the failed
+		 * VCPUs to come up.
+		 */
+		if (other_cpu && is_up && (rc == 0) &&
+		    HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
+			BUG();
+	}
 }
 
-void xen_vcpu_setup(int cpu)
+void xen_vcpu_info_reset(int cpu)
+{
+	if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS) {
+		per_cpu(xen_vcpu, cpu) =
+			&HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
+	} else {
+		/* Set to NULL so that if somebody accesses it we get an OOPS */
+		per_cpu(xen_vcpu, cpu) = NULL;
+	}
+}
+
+int xen_vcpu_setup(int cpu)
 {
 	struct vcpu_register_vcpu_info info;
 	int err;
@@ -123,11 +191,11 @@ void xen_vcpu_setup(int cpu)
 	BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
 
 	/*
-	 * This path is called twice on PVHVM - first during bootup via
-	 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
-	 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
-	 * As we can only do the VCPUOP_register_vcpu_info once lets
-	 * not over-write its result.
+	 * This path is called on PVHVM at bootup (xen_hvm_smp_prepare_boot_cpu)
+	 * and at restore (xen_vcpu_restore). Also called for hotplugged
+	 * VCPUs (cpu_init -> xen_hvm_cpu_prepare_hvm).
+	 * However, the hypercall can only be done once (see below) so if a VCPU
+	 * is offlined and comes back online then let's not redo the hypercall.
 	 *
 	 * For PV it is called during restore (xen_vcpu_restore) and bootup
 	 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
@@ -135,42 +203,44 @@ void xen_vcpu_setup(int cpu)
 	 */
 	if (xen_hvm_domain()) {
 		if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
-			return;
+			return 0;
 	}
-	if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
-		per_cpu(xen_vcpu, cpu) =
-			&HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
 
-	if (!xen_have_vcpu_info_placement) {
-		if (cpu >= MAX_VIRT_CPUS)
-			clamp_max_cpus();
-		return;
+	if (xen_have_vcpu_info_placement) {
+		vcpup = &per_cpu(xen_vcpu_info, cpu);
+		info.mfn = arbitrary_virt_to_mfn(vcpup);
+		info.offset = offset_in_page(vcpup);
+
+		/*
+		 * Check to see if the hypervisor will put the vcpu_info
+		 * structure where we want it, which allows direct access via
+		 * a percpu-variable.
+		 * N.B. This hypercall can _only_ be called once per CPU.
+		 * Subsequent calls will error out with -EINVAL. This is due to
+		 * the fact that hypervisor has no unregister variant and this
+		 * hypercall does not allow to over-write info.mfn and
+		 * info.offset.
+		 */
+		err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info,
+					 xen_vcpu_nr(cpu), &info);
+
+		if (err) {
+			pr_warn_once("register_vcpu_info failed: cpu=%d err=%d\n",
+				     cpu, err);
+			xen_have_vcpu_info_placement = 0;
+		} else {
+			/*
+			 * This cpu is using the registered vcpu info, even if
+			 * later ones fail to.
+			 */
+			per_cpu(xen_vcpu, cpu) = vcpup;
+		}
 	}
 
-	vcpup = &per_cpu(xen_vcpu_info, cpu);
-	info.mfn = arbitrary_virt_to_mfn(vcpup);
-	info.offset = offset_in_page(vcpup);
-
-	/* Check to see if the hypervisor will put the vcpu_info
-	   structure where we want it, which allows direct access via
-	   a percpu-variable.
-	   N.B. This hypercall can _only_ be called once per CPU. Subsequent
-	   calls will error out with -EINVAL. This is due to the fact that
-	   hypervisor has no unregister variant and this hypercall does not
-	   allow to over-write info.mfn and info.offset.
-	 */
-	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
-				 &info);
+	if (!xen_have_vcpu_info_placement)
+		xen_vcpu_info_reset(cpu);
 
-	if (err) {
-		printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
-		xen_have_vcpu_info_placement = 0;
-		clamp_max_cpus();
-	} else {
-		/* This cpu is using the registered vcpu info, even if
-		   later ones fail to. */
-		per_cpu(xen_vcpu, cpu) = vcpup;
-	}
+	return ((per_cpu(xen_vcpu, cpu) == NULL) ? -ENODEV : 0);
 }
 
 void xen_reboot(int reason)
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index a6d014f..87d7913 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -1,5 +1,6 @@
 #include <linux/cpu.h>
 #include <linux/kexec.h>
+#include <linux/memblock.h>
 
 #include <xen/features.h>
 #include <xen/events.h>
@@ -10,9 +11,11 @@
 #include <asm/reboot.h>
 #include <asm/setup.h>
 #include <asm/hypervisor.h>
+#include <asm/e820/api.h>
 
 #include <asm/xen/cpuid.h>
 #include <asm/xen/hypervisor.h>
+#include <asm/xen/page.h>
 
 #include "xen-ops.h"
 #include "mmu.h"
@@ -20,37 +23,34 @@
 
 void __ref xen_hvm_init_shared_info(void)
 {
-	int cpu;
 	struct xen_add_to_physmap xatp;
-	static struct shared_info *shared_info_page;
+	u64 pa;
+
+	if (HYPERVISOR_shared_info == &xen_dummy_shared_info) {
+		/*
+		 * Search for a free page starting at 4kB physical address.
+		 * Low memory is preferred to avoid an EPT large page split up
+		 * by the mapping.
+		 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
+		 * the BIOS used for HVM guests is well behaved and won't
+		 * clobber memory other than the first 4kB.
+		 */
+		for (pa = PAGE_SIZE;
+		     !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
+		     memblock_is_reserved(pa);
+		     pa += PAGE_SIZE)
+			;
+
+		memblock_reserve(pa, PAGE_SIZE);
+		HYPERVISOR_shared_info = __va(pa);
+	}
 
-	if (!shared_info_page)
-		shared_info_page = (struct shared_info *)
-			extend_brk(PAGE_SIZE, PAGE_SIZE);
 	xatp.domid = DOMID_SELF;
 	xatp.idx = 0;
 	xatp.space = XENMAPSPACE_shared_info;
-	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
+	xatp.gpfn = virt_to_pfn(HYPERVISOR_shared_info);
 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 		BUG();
-
-	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
-
-	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
-	 * page, we use it in the event channel upcall and in some pvclock
-	 * related functions. We don't need the vcpu_info placement
-	 * optimizations because we don't use any pv_mmu or pv_irq op on
-	 * HVM.
-	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
-	 * online but xen_hvm_init_shared_info is run at resume time too and
-	 * in that case multiple vcpus might be online. */
-	for_each_online_cpu(cpu) {
-		/* Leave it to be NULL. */
-		if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
-			continue;
-		per_cpu(xen_vcpu, cpu) =
-			&HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
-	}
 }
 
 static void __init init_hvm_pv_info(void)
@@ -106,7 +106,7 @@ static void xen_hvm_crash_shutdown(struct pt_regs *regs)
 
 static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 {
-	int rc;
+	int rc = 0;
 
 	/*
 	 * This can happen if CPU was offlined earlier and
@@ -121,7 +121,9 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
 	else
 		per_cpu(xen_vcpu_id, cpu) = cpu;
-	xen_vcpu_setup(cpu);
+	rc = xen_vcpu_setup(cpu);
+	if (rc)
+		return rc;
 
 	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
 		xen_setup_timer(cpu);
@@ -130,9 +132,8 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 	if (rc) {
 		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
 		     cpu, rc);
-		return rc;
 	}
-	return 0;
+	return rc;
 }
 
 static int xen_cpu_dead_hvm(unsigned int cpu)
@@ -154,6 +155,13 @@ static void __init xen_hvm_guest_init(void)
 
 	xen_hvm_init_shared_info();
 
+	/*
+	 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+	 * page, we use it in the event channel upcall and in some pvclock
+	 * related functions.
+	 */
+	xen_vcpu_info_reset(0);
+
 	xen_panic_handler_init();
 
 	if (xen_feature(XENFEAT_hvm_callback_vector))
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index f33eef4..811e4dd 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -89,8 +89,6 @@
 
 void *xen_initial_gdt;
 
-RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
-
 static int xen_cpu_up_prepare_pv(unsigned int cpu);
 static int xen_cpu_dead_pv(unsigned int cpu);
 
@@ -107,35 +105,6 @@ struct tls_descs {
  */
 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
 
-/*
- * On restore, set the vcpu placement up again.
- * If it fails, then we're in a bad state, since
- * we can't back out from using it...
- */
-void xen_vcpu_restore(void)
-{
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		bool other_cpu = (cpu != smp_processor_id());
-		bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
-						NULL);
-
-		if (other_cpu && is_up &&
-		    HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
-			BUG();
-
-		xen_setup_runstate_info(cpu);
-
-		if (xen_have_vcpu_info_placement)
-			xen_vcpu_setup(cpu);
-
-		if (other_cpu && is_up &&
-		    HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
-			BUG();
-	}
-}
-
 static void __init xen_banner(void)
 {
 	unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
@@ -960,30 +929,43 @@ void xen_setup_shared_info(void)
 	HYPERVISOR_shared_info =
 		(struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
 
-#ifndef CONFIG_SMP
-	/* In UP this is as good a place as any to set up shared info */
-	xen_setup_vcpu_info_placement();
-#endif
-
 	xen_setup_mfn_list_list();
 
-	/*
-	 * Now that shared info is set up we can start using routines that
-	 * point to pvclock area.
-	 */
-	if (system_state == SYSTEM_BOOTING)
+	if (system_state == SYSTEM_BOOTING) {
+#ifndef CONFIG_SMP
+		/*
+		 * In UP this is as good a place as any to set up shared info.
+		 * Limit this to boot only, at restore vcpu setup is done via
+		 * xen_vcpu_restore().
+		 */
+		xen_setup_vcpu_info_placement();
+#endif
+		/*
+		 * Now that shared info is set up we can start using routines
+		 * that point to pvclock area.
+		 */
 		xen_init_time_ops();
+	}
 }
 
 /* This is called once we have the cpu_possible_mask */
-void xen_setup_vcpu_info_placement(void)
+void __ref xen_setup_vcpu_info_placement(void)
 {
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
 		/* Set up direct vCPU id mapping for PV guests. */
 		per_cpu(xen_vcpu_id, cpu) = cpu;
-		xen_vcpu_setup(cpu);
+
+		/*
+		 * xen_vcpu_setup(cpu) can fail  -- in which case it
+		 * falls back to the shared_info version for cpus
+		 * where xen_vcpu_nr(cpu) < MAX_VIRT_CPUS.
+		 *
+		 * xen_cpu_up_prepare_pv() handles the rest by failing
+		 * them in hotplug.
+		 */
+		(void) xen_vcpu_setup(cpu);
 	}
 
 	/*
@@ -1332,9 +1314,17 @@ asmlinkage __visible void __init xen_start_kernel(void)
 	 */
 	acpi_numa = -1;
 #endif
-	/* Don't do the full vcpu_info placement stuff until we have a
-	   possible map and a non-dummy shared_info. */
-	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
+	/* Let's presume PV guests always boot on vCPU with id 0. */
+	per_cpu(xen_vcpu_id, 0) = 0;
+
+	/*
+	 * Setup xen_vcpu early because start_kernel needs it for
+	 * local_irq_disable(), irqs_disabled().
+	 *
+	 * Don't do the full vcpu_info placement stuff until we have
+	 * the cpu_possible_mask and a non-dummy shared_info.
+	 */
+	xen_vcpu_info_reset(0);
 
 	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_pv, xen_cpu_dead_pv));
 
@@ -1431,9 +1421,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 #endif
 	xen_raw_console_write("about to get started...\n");
 
-	/* Let's presume PV guests always boot on vCPU with id 0. */
-	per_cpu(xen_vcpu_id, 0) = 0;
-
+	/* We need this for printk timestamps */
 	xen_setup_runstate_info(0);
 
 	xen_efi_init();
@@ -1451,6 +1439,9 @@ static int xen_cpu_up_prepare_pv(unsigned int cpu)
 {
 	int rc;
 
+	if (per_cpu(xen_vcpu, cpu) == NULL)
+		return -ENODEV;
+
 	xen_setup_timer(cpu);
 
 	rc = xen_smp_intr_init(cpu);
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index a5bf7c4..c810463 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -499,7 +499,7 @@ static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
 void __init xen_remap_memory(void)
 {
 	unsigned long buf = (unsigned long)&xen_remap_buf;
-	unsigned long mfn_save, mfn, pfn;
+	unsigned long mfn_save, pfn;
 	unsigned long remapped = 0;
 	unsigned int i;
 	unsigned long pfn_s = ~0UL;
@@ -515,8 +515,7 @@ void __init xen_remap_memory(void)
 
 		pfn = xen_remap_buf.target_pfn;
 		for (i = 0; i < xen_remap_buf.size; i++) {
-			mfn = xen_remap_buf.mfns[i];
-			xen_update_mem_tables(pfn, mfn);
+			xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
 			remapped++;
 			pfn++;
 		}
@@ -530,8 +529,6 @@ void __init xen_remap_memory(void)
 			pfn_s = xen_remap_buf.target_pfn;
 			len = xen_remap_buf.size;
 		}
-
-		mfn = xen_remap_mfn;
 		xen_remap_mfn = xen_remap_buf.next_area_mfn;
 	}
 
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 82ac611..e7f02eb 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);
diff --git a/arch/x86/xen/smp.h b/arch/x86/xen/smp.h
index 8ebb6ac..87d3c76 100644
--- a/arch/x86/xen/smp.h
+++ b/arch/x86/xen/smp.h
@@ -14,6 +14,8 @@ extern void xen_smp_intr_free(unsigned int cpu);
 int xen_smp_intr_init_pv(unsigned int cpu);
 void xen_smp_intr_free_pv(unsigned int cpu);
 
+void xen_smp_cpus_done(unsigned int max_cpus);
+
 void xen_smp_send_reschedule(int cpu);
 void xen_smp_send_call_function_ipi(const struct cpumask *mask);
 void xen_smp_send_call_function_single_ipi(int cpu);
diff --git a/arch/x86/xen/smp_hvm.c b/arch/x86/xen/smp_hvm.c
index f18561b..fd60abe 100644
--- a/arch/x86/xen/smp_hvm.c
+++ b/arch/x86/xen/smp_hvm.c
@@ -12,7 +12,8 @@ static void __init xen_hvm_smp_prepare_boot_cpu(void)
 	native_smp_prepare_boot_cpu();
 
 	/*
-	 * Setup vcpu_info for boot CPU.
+	 * Setup vcpu_info for boot CPU. Secondary CPUs get their vcpu_info
+	 * in xen_cpu_up_prepare_hvm().
 	 */
 	xen_vcpu_setup(0);
 
@@ -27,10 +28,20 @@ static void __init xen_hvm_smp_prepare_boot_cpu(void)
 
 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
 {
+	int cpu;
+
 	native_smp_prepare_cpus(max_cpus);
 	WARN_ON(xen_smp_intr_init(0));
 
 	xen_init_lock_cpu(0);
+
+	for_each_possible_cpu(cpu) {
+		if (cpu == 0)
+			continue;
+
+		/* Set default vcpu_id to make sure that we don't use cpu-0's */
+		per_cpu(xen_vcpu_id, cpu) = XEN_VCPU_ID_INVALID;
+	}
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -60,4 +71,5 @@ void __init xen_hvm_smp_init(void)
 	smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
 	smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
 	smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
+	smp_ops.smp_cpus_done = xen_smp_cpus_done;
 }
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index aae3253..1ea598e 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -371,10 +371,6 @@ static int xen_pv_cpu_up(unsigned int cpu, struct task_struct *idle)
 	return 0;
 }
 
-static void xen_pv_smp_cpus_done(unsigned int max_cpus)
-{
-}
-
 #ifdef CONFIG_HOTPLUG_CPU
 static int xen_pv_cpu_disable(void)
 {
@@ -469,7 +465,7 @@ static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
 static const struct smp_ops xen_smp_ops __initconst = {
 	.smp_prepare_boot_cpu = xen_pv_smp_prepare_boot_cpu,
 	.smp_prepare_cpus = xen_pv_smp_prepare_cpus,
-	.smp_cpus_done = xen_pv_smp_cpus_done,
+	.smp_cpus_done = xen_smp_cpus_done,
 
 	.cpu_up = xen_pv_cpu_up,
 	.cpu_die = xen_pv_cpu_die,
diff --git a/arch/x86/xen/suspend_hvm.c b/arch/x86/xen/suspend_hvm.c
index 01afcad..4849994 100644
--- a/arch/x86/xen/suspend_hvm.c
+++ b/arch/x86/xen/suspend_hvm.c
@@ -8,15 +8,10 @@
 
 void xen_hvm_post_suspend(int suspend_cancelled)
 {
-	int cpu;
-
-	if (!suspend_cancelled)
+	if (!suspend_cancelled) {
 		xen_hvm_init_shared_info();
+		xen_vcpu_restore();
+	}
 	xen_callback_vector();
 	xen_unplug_emulated_devices();
-	if (xen_feature(XENFEAT_hvm_safe_pvclock)) {
-		for_each_online_cpu(cpu) {
-			xen_setup_runstate_info(cpu);
-		}
-	}
 }
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 9a440a4..0d50044 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -78,7 +78,8 @@ bool xen_vcpu_stolen(int vcpu);
 
 extern int xen_have_vcpu_info_placement;
 
-void xen_vcpu_setup(int cpu);
+int xen_vcpu_setup(int cpu);
+void xen_vcpu_info_reset(int cpu);
 void xen_setup_vcpu_info_placement(void);
 
 #ifdef CONFIG_SMP