6 files changed, 132 insertions, 17 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 59bcb96ac36..f5760927544 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 59c226d120c..c20d1ce62dc 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 0e863703545..74354708c6c 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 912ac81b6db..0be4df39e95 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 00000000000..0ef7c4d40f8
--- /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 b193fa2f9fd..13e43e41637 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;