Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "Features and fixes for 4.8-rc0:

   - ACPI support for guests on ARM platforms.
   - Generic steal time support for arm and x86.
   - Support cases where kernel cpu is not Xen VCPU number (e.g., if
     in-guest kexec is used).
   - Use the system workqueue instead of a custom workqueue in various
     places"

* tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits)
  xen: add static initialization of steal_clock op to xen_time_ops
  xen/pvhvm: run xen_vcpu_setup() for the boot CPU
  xen/evtchn: use xen_vcpu_id mapping
  xen/events: fifo: use xen_vcpu_id mapping
  xen/events: use xen_vcpu_id mapping in events_base
  x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info
  x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
  xen: introduce xen_vcpu_id mapping
  x86/acpi: store ACPI ids from MADT for future usage
  x86/xen: update cpuid.h from Xen-4.7
  xen/evtchn: add IOCTL_EVTCHN_RESTRICT
  xen-blkback: really don't leak mode property
  xen-blkback: constify instance of "struct attribute_group"
  xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
  xen-blkback: prefer xenbus_scanf() over xenbus_gather()
  xen: support runqueue steal time on xen
  arm/xen: add support for vm_assist hypercall
  xen: update xen headers
  xen-pciback: drop superfluous variables
  xen-pciback: short-circuit read path used for merging write values
  ...

1 files changed, 37 insertions, 12 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0f87db2cc6a8..69b4b6d29738 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -59,6 +59,7 @@
 #include <asm/xen/pci.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
+#include <asm/xen/cpuid.h>
 #include <asm/fixmap.h>
 #include <asm/processor.h>
 #include <asm/proto.h>
@@ -118,6 +119,10 @@ DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  */
 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
 
+/* Linux <-> Xen vCPU id mapping */
+DEFINE_PER_CPU(int, xen_vcpu_id) = -1;
+EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
+
 enum xen_domain_type xen_domain_type = XEN_NATIVE;
 EXPORT_SYMBOL_GPL(xen_domain_type);
 
@@ -179,7 +184,7 @@ static void clamp_max_cpus(void)
 #endif
 }
 
-static void xen_vcpu_setup(int cpu)
+void xen_vcpu_setup(int cpu)
 {
         struct vcpu_register_vcpu_info info;
         int err;
@@ -202,8 +207,9 @@ static void xen_vcpu_setup(int cpu)
                 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
                         return;
         }
-        if (cpu < MAX_VIRT_CPUS)
-                per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+        if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
+                per_cpu(xen_vcpu, cpu) =
+                        &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
 
         if (!have_vcpu_info_placement) {
                 if (cpu >= MAX_VIRT_CPUS)
@@ -223,7 +229,8 @@ static void xen_vcpu_setup(int cpu)
            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, cpu, &info);
+        err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
+                                 &info);
 
         if (err) {
                 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
@@ -247,10 +254,11 @@ void xen_vcpu_restore(void)
 
         for_each_possible_cpu(cpu) {
                 bool other_cpu = (cpu != smp_processor_id());
-                bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL);
+                bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
+                                                NULL);
 
                 if (other_cpu && is_up &&
-                    HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
+                    HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
                         BUG();
 
                 xen_setup_runstate_info(cpu);
@@ -259,7 +267,7 @@ void xen_vcpu_restore(void)
                         xen_vcpu_setup(cpu);
 
                 if (other_cpu && is_up &&
-                    HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
+                    HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
                         BUG();
         }
 }
@@ -588,7 +596,7 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
 {
         unsigned long va = dtr->address;
         unsigned int size = dtr->size + 1;
-        unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
+        unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
         unsigned long frames[pages];
         int f;
 
@@ -637,7 +645,7 @@ static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
 {
         unsigned long va = dtr->address;
         unsigned int size = dtr->size + 1;
-        unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
+        unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
         unsigned long frames[pages];
         int f;
 
@@ -1135,8 +1143,11 @@ void xen_setup_vcpu_info_placement(void)
 {
         int cpu;
 
-        for_each_possible_cpu(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 managed to place the vcpu_info within the
          * percpu area for all cpus, so make use of it. Note that for
@@ -1727,6 +1738,9 @@ 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;
+
         xen_setup_runstate_info(0);
 
         xen_efi_init();
@@ -1768,9 +1782,10 @@ void __ref xen_hvm_init_shared_info(void)
          * in that case multiple vcpus might be online. */
         for_each_online_cpu(cpu) {
                 /* Leave it to be NULL. */
-                if (cpu >= MAX_VIRT_CPUS)
+                if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
                         continue;
-                per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+                per_cpu(xen_vcpu, cpu) =
+                        &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
         }
 }
 
@@ -1795,6 +1810,12 @@ static void __init init_hvm_pv_info(void)
 
         xen_setup_features();
 
+        cpuid(base + 4, &eax, &ebx, &ecx, &edx);
+        if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
+                this_cpu_write(xen_vcpu_id, ebx);
+        else
+                this_cpu_write(xen_vcpu_id, smp_processor_id());
+
         pv_info.name = "Xen HVM";
 
         xen_domain_type = XEN_HVM_DOMAIN;
@@ -1806,6 +1827,10 @@ static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action,
         int cpu = (long)hcpu;
         switch (action) {
         case CPU_UP_PREPARE:
+                if (cpu_acpi_id(cpu) != U32_MAX)
+                        per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
+                else
+                        per_cpu(xen_vcpu_id, cpu) = cpu;
                 xen_vcpu_setup(cpu);
                 if (xen_have_vector_callback) {
                         if (xen_feature(XENFEAT_hvm_safe_pvclock))