2 files changed, 72 insertions, 1 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index fac5e4f9607c..115016347806 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -40,6 +40,7 @@
 #include <xen/interface/physdev.h>
 #include <xen/interface/vcpu.h>
 #include <xen/interface/memory.h>
+#include <xen/interface/nmi.h>
 #include <xen/interface/xen-mca.h>
 #include <xen/features.h>
 #include <xen/page.h>
@@ -66,6 +67,7 @@
 #include <asm/reboot.h>
 #include <asm/stackprotector.h>
 #include <asm/hypervisor.h>
+#include <asm/mach_traps.h>
 #include <asm/mwait.h>
 #include <asm/pci_x86.h>
 #include <asm/pat.h>
@@ -1357,6 +1359,21 @@ static const struct machine_ops xen_machine_ops __initconst = {
         .emergency_restart = xen_emergency_restart,
 };
 
+static unsigned char xen_get_nmi_reason(void)
+{
+        unsigned char reason = 0;
+
+        /* Construct a value which looks like it came from port 0x61. */
+        if (test_bit(_XEN_NMIREASON_io_error,
+                     &HYPERVISOR_shared_info->arch.nmi_reason))
+                reason |= NMI_REASON_IOCHK;
+        if (test_bit(_XEN_NMIREASON_pci_serr,
+                     &HYPERVISOR_shared_info->arch.nmi_reason))
+                reason |= NMI_REASON_SERR;
+
+        return reason;
+}
+
 static void __init xen_boot_params_init_edd(void)
 {
 #if IS_ENABLED(CONFIG_EDD)
@@ -1541,9 +1558,12 @@ asmlinkage __visible void __init xen_start_kernel(void)
         pv_info = xen_info;
         pv_init_ops = xen_init_ops;
         pv_apic_ops = xen_apic_ops;
-        if (!xen_pvh_domain())
+        if (!xen_pvh_domain()) {
                 pv_cpu_ops = xen_cpu_ops;
 
+                x86_platform.get_nmi_reason = xen_get_nmi_reason;
+        }
+
         if (xen_feature(XENFEAT_auto_translated_physmap))
                 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
         else
diff --git a/include/xen/interface/nmi.h b/include/xen/interface/nmi.h
new file mode 100644
index 000000000000..b47d9d06fade
--- /dev/null
+++ b/include/xen/interface/nmi.h
@@ -0,0 +1,51 @@
+/******************************************************************************
+ * nmi.h
+ *
+ * NMI callback registration and reason codes.
+ *
+ * Copyright (c) 2005, Keir Fraser <keir@xensource.com>
+ */
+
+#ifndef __XEN_PUBLIC_NMI_H__
+#define __XEN_PUBLIC_NMI_H__
+
+#include <xen/interface/xen.h>
+
+/*
+ * NMI reason codes:
+ * Currently these are x86-specific, stored in arch_shared_info.nmi_reason.
+ */
+ /* I/O-check error reported via ISA port 0x61, bit 6. */
+#define _XEN_NMIREASON_io_error     0
+#define XEN_NMIREASON_io_error      (1UL << _XEN_NMIREASON_io_error)
+ /* PCI SERR reported via ISA port 0x61, bit 7. */
+#define _XEN_NMIREASON_pci_serr     1
+#define XEN_NMIREASON_pci_serr      (1UL << _XEN_NMIREASON_pci_serr)
+ /* Unknown hardware-generated NMI. */
+#define _XEN_NMIREASON_unknown      2
+#define XEN_NMIREASON_unknown       (1UL << _XEN_NMIREASON_unknown)
+
+/*
+ * long nmi_op(unsigned int cmd, void *arg)
+ * NB. All ops return zero on success, else a negative error code.
+ */
+
+/*
+ * Register NMI callback for this (calling) VCPU. Currently this only makes
+ * sense for domain 0, vcpu 0. All other callers will be returned EINVAL.
+ * arg == pointer to xennmi_callback structure.
+ */
+#define XENNMI_register_callback   0
+struct xennmi_callback {
+    unsigned long handler_address;
+    unsigned long pad;
+};
+DEFINE_GUEST_HANDLE_STRUCT(xennmi_callback);
+
+/*
+ * Deregister NMI callback for this (calling) VCPU.
+ * arg == NULL.
+ */
+#define XENNMI_unregister_callback 1
+
+#endif /* __XEN_PUBLIC_NMI_H__ */