Merge tag 'stable/for-linus-3.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "There are three ARM compile fixes (we forgot to export certain
  functions and if the drivers are built as an module - we go belly-up).

  There is also an mismatch of irq_enter() / exit_idle() calls sequence
  which were fixed some time ago in other piece of codes, but failed to
  appear in the Xen code.

  Lastly a fix for to help in the field with troubleshooting in case we
  cannot get the appropriate parameter and also fallback code when
  working with very old hypervisors."

Bug-fixes:
 - Fix compile issues on ARM.
 - Fix hypercall fallback code for old hypervisors.
 - Print out which HVM parameter failed if it fails.
 - Fix idle notifier call after irq_enter.

* tag 'stable/for-linus-3.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/arm: Fix compile errors when drivers are compiled as modules (export more).
  xen/arm: Fix compile errors when drivers are compiled as modules.
  xen/generic: Disable fallback build on ARM.
  xen/events: fix RCU warning, or Call idle notifier after irq_enter()
  xen/hvm: If we fail to fetch an HVM parameter print out which flag it is.
  xen/hypercall: fix hypercall fallback code for very old hypervisors

6 files changed, 132 insertions, 17 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 59bcb96ac369..f57609275449 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -166,3 +166,14 @@ void free_xenballooned_pages(int nr_pages, struct page **pages)
         *pages = NULL;
 }
 EXPORT_SYMBOL_GPL(free_xenballooned_pages);
+
+/* In the hypervisor.S file. */
+EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
+EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
+EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
+EXPORT_SYMBOL_GPL(privcmd_call);
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index 59c226d120cd..c20d1ce62dc6 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -359,18 +359,14 @@ HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
                 return _hypercall4(int, update_va_mapping, va,
                                    new_val.pte, new_val.pte >> 32, flags);
 }
+extern int __must_check xen_event_channel_op_compat(int, void *);
 
 static inline int
 HYPERVISOR_event_channel_op(int cmd, void *arg)
 {
         int rc = _hypercall2(int, event_channel_op, cmd, arg);
-        if (unlikely(rc == -ENOSYS)) {
-                struct evtchn_op op;
-                op.cmd = cmd;
-                memcpy(&op.u, arg, sizeof(op.u));
-                rc = _hypercall1(int, event_channel_op_compat, &op);
-                memcpy(arg, &op.u, sizeof(op.u));
-        }
+        if (unlikely(rc == -ENOSYS))
+                rc = xen_event_channel_op_compat(cmd, arg);
         return rc;
 }
 
@@ -386,17 +382,14 @@ HYPERVISOR_console_io(int cmd, int count, char *str)
         return _hypercall3(int, console_io, cmd, count, str);
 }
 
+extern int __must_check HYPERVISOR_physdev_op_compat(int, void *);
+
 static inline int
 HYPERVISOR_physdev_op(int cmd, void *arg)
 {
         int rc = _hypercall2(int, physdev_op, cmd, arg);
-        if (unlikely(rc == -ENOSYS)) {
-                struct physdev_op op;
-                op.cmd = cmd;
-                memcpy(&op.u, arg, sizeof(op.u));
-                rc = _hypercall1(int, physdev_op_compat, &op);
-                memcpy(arg, &op.u, sizeof(op.u));
-        }
+        if (unlikely(rc == -ENOSYS))
+                rc = HYPERVISOR_physdev_op_compat(cmd, arg);
         return rc;
 }
 
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 0e8637035457..74354708c6c4 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -2,6 +2,7 @@ ifneq ($(CONFIG_ARM),y)
 obj-y   += manage.o balloon.o
 obj-$(CONFIG_HOTPLUG_CPU)               += cpu_hotplug.o
 endif
+obj-$(CONFIG_X86)                       += fallback.o
 obj-y   += grant-table.o features.o events.o
 obj-y   += xenbus/
 
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 912ac81b6dbf..0be4df39e953 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -1395,10 +1395,10 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 {
         struct pt_regs *old_regs = set_irq_regs(regs);
 
+        irq_enter();
 #ifdef CONFIG_X86
         exit_idle();
 #endif
-        irq_enter();
 
         __xen_evtchn_do_upcall();
 
diff --git a/drivers/xen/fallback.c b/drivers/xen/fallback.c
new file mode 100644
index 000000000000..0ef7c4d40f86
--- /dev/null
+++ b/drivers/xen/fallback.c
@@ -0,0 +1,80 @@
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/bug.h>
+#include <linux/export.h>
+#include <asm/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+int xen_event_channel_op_compat(int cmd, void *arg)
+{
+        struct evtchn_op op;
+        int rc;
+
+        op.cmd = cmd;
+        memcpy(&op.u, arg, sizeof(op.u));
+        rc = _hypercall1(int, event_channel_op_compat, &op);
+
+        switch (cmd) {
+        case EVTCHNOP_close:
+        case EVTCHNOP_send:
+        case EVTCHNOP_bind_vcpu:
+        case EVTCHNOP_unmask:
+                /* no output */
+                break;
+
+#define COPY_BACK(eop) \
+        case EVTCHNOP_##eop: \
+                memcpy(arg, &op.u.eop, sizeof(op.u.eop)); \
+                break
+
+        COPY_BACK(bind_interdomain);
+        COPY_BACK(bind_virq);
+        COPY_BACK(bind_pirq);
+        COPY_BACK(status);
+        COPY_BACK(alloc_unbound);
+        COPY_BACK(bind_ipi);
+#undef COPY_BACK
+
+        default:
+                WARN_ON(rc != -ENOSYS);
+                break;
+        }
+
+        return rc;
+}
+EXPORT_SYMBOL_GPL(xen_event_channel_op_compat);
+
+int HYPERVISOR_physdev_op_compat(int cmd, void *arg)
+{
+        struct physdev_op op;
+        int rc;
+
+        op.cmd = cmd;
+        memcpy(&op.u, arg, sizeof(op.u));
+        rc = _hypercall1(int, physdev_op_compat, &op);
+
+        switch (cmd) {
+        case PHYSDEVOP_IRQ_UNMASK_NOTIFY:
+        case PHYSDEVOP_set_iopl:
+        case PHYSDEVOP_set_iobitmap:
+        case PHYSDEVOP_apic_write:
+                /* no output */
+                break;
+
+#define COPY_BACK(pop, fld) \
+        case PHYSDEVOP_##pop: \
+                memcpy(arg, &op.u.fld, sizeof(op.u.fld)); \
+                break
+
+        COPY_BACK(irq_status_query, irq_status_query);
+        COPY_BACK(apic_read, apic_op);
+        COPY_BACK(ASSIGN_VECTOR, irq_op);
+#undef COPY_BACK
+
+        default:
+                WARN_ON(rc != -ENOSYS);
+                break;
+        }
+
+        return rc;
+}
diff --git a/include/xen/hvm.h b/include/xen/hvm.h
index b193fa2f9fdd..13e43e41637d 100644
--- a/include/xen/hvm.h
+++ b/include/xen/hvm.h
@@ -5,6 +5,36 @@
 #include <xen/interface/hvm/params.h>
 #include <asm/xen/hypercall.h>
 
+static const char *param_name(int op)
+{
+#define PARAM(x) [HVM_PARAM_##x] = #x
+        static const char *const names[] = {
+                PARAM(CALLBACK_IRQ),
+                PARAM(STORE_PFN),
+                PARAM(STORE_EVTCHN),
+                PARAM(PAE_ENABLED),
+                PARAM(IOREQ_PFN),
+                PARAM(BUFIOREQ_PFN),
+                PARAM(TIMER_MODE),
+                PARAM(HPET_ENABLED),
+                PARAM(IDENT_PT),
+                PARAM(DM_DOMAIN),
+                PARAM(ACPI_S_STATE),
+                PARAM(VM86_TSS),
+                PARAM(VPT_ALIGN),
+                PARAM(CONSOLE_PFN),
+                PARAM(CONSOLE_EVTCHN),
+        };
+#undef PARAM
+
+        if (op >= ARRAY_SIZE(names))
+                return "unknown";
+
+        if (!names[op])
+                return "reserved";
+
+        return names[op];
+}
 static inline int hvm_get_parameter(int idx, uint64_t *value)
 {
         struct xen_hvm_param xhv;
@@ -14,8 +44,8 @@ static inline int hvm_get_parameter(int idx, uint64_t *value)
         xhv.index = idx;
         r = HYPERVISOR_hvm_op(HVMOP_get_param, &xhv);
         if (r < 0) {
-                printk(KERN_ERR "Cannot get hvm parameter %d: %d!\n",
-                        idx, r);
+                printk(KERN_ERR "Cannot get hvm parameter %s (%d): %d!\n",
+                        param_name(idx), idx, r);
                 return r;
         }
         *value = xhv.value;