x86: restore (optional) forwarding of PCI SERR induced NMI to Dom0

c/s 22949:54fe1011f86b removed the forwarding of NMIs to Dom0 when they
were caused by PCI SERR. NMI buttons as well as BMCs (like HP's iLO)
may however want such events to be seen in Dom0 (e.g. to trigger a
dump).

Therefore restore most of the functionality which named c/s removed
(adjusted for subsequent changes, and adjusting the public interface to
use the modern term, retaining the old one for backwards
compatibility).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Keir Fraser <keir@xen.org>

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index ab4e85e1f56efbd273eac8215a19d57c8b4409f0..a97033d1a60b5a6a4c2fe26018d61a30a32f9774 100644 (file)
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -3089,6 +3089,7 @@ static void nmi_mce_softirq(void)
 static void pci_serr_softirq(void)
 {
     printk("\n\nNMI - PCI system error (SERR)\n");
+    outb(inb(0x61) & 0x0b, 0x61); /* re-enable the PCI SERR error line. */
 }
 
 void async_exception_cleanup(struct vcpu *curr)
@@ -3135,9 +3136,20 @@ static void pci_serr_error(struct cpu_user_regs *regs)
 {
     outb((inb(0x61) & 0x0f) | 0x04, 0x61); /* clear-and-disable the PCI SERR error line. */
 
-    /* Would like to print a diagnostic here but can't call printk()
-       from NMI context -- raise a softirq instead. */
-    raise_softirq(PCI_SERR_SOFTIRQ);
+    switch ( opt_nmi[0] )
+    {
+    case 'd': /* 'dom0' */
+        nmi_dom0_report(_XEN_NMIREASON_pci_serr);
+    case 'i': /* 'ignore' */
+        /* Would like to print a diagnostic here but can't call printk()
+           from NMI context -- raise a softirq instead. */
+        raise_softirq(PCI_SERR_SOFTIRQ);
+        break;
+    default:  /* 'fatal' */
+        console_force_unlock();
+        printk("\n\nNMI - PCI system error (SERR)\n");
+        fatal_trap(TRAP_nmi, regs);
+    }
 }
 
 static void io_check_error(struct cpu_user_regs *regs)

diff --git a/xen/include/public/nmi.h b/xen/include/public/nmi.h
index 2fd21d2dad5059b90705412435883fbbec1111a0..0be9d5cbf737320a054f5ebcf27c2d65758ec196 100644 (file)
--- a/xen/include/public/nmi.h
+++ b/xen/include/public/nmi.h
@@ -36,9 +36,14 @@
  /* 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)
+#if __XEN_INTERFACE_VERSION__ < 0x00040300 /* legacy alias of the above */
  /* Parity error reported via ISA port 0x61, bit 7. */
 #define _XEN_NMIREASON_parity_error 1
 #define XEN_NMIREASON_parity_error  (1UL << _XEN_NMIREASON_parity_error)
+#endif
  /* Unknown hardware-generated NMI. */
 #define _XEN_NMIREASON_unknown      2
 #define XEN_NMIREASON_unknown       (1UL << _XEN_NMIREASON_unknown)