From 47b10421a6f90df256e77ae8086e4dc3760313a3 Mon Sep 17 00:00:00 2001
From: sborrill <sborrill@NetBSD.org>
Date: Tue, 6 May 2014 09:01:26 +0000
Subject: [PATCH] Force pci_mode 1 when running as Xen HVM domU to allow cd* to
 be detected correctly. Fixes kern/48770. Thanks to cube@

---
 sys/arch/x86/pci/pci_machdep.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/sys/arch/x86/pci/pci_machdep.c b/sys/arch/x86/pci/pci_machdep.c
index 856dad66a3c7..5648f9dd47b2 100644
--- a/sys/arch/x86/pci/pci_machdep.c
+++ b/sys/arch/x86/pci/pci_machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: pci_machdep.c,v 1.65 2014/01/27 23:11:50 jakllsch Exp $	*/
+/*	$NetBSD: pci_machdep.c,v 1.66 2014/05/06 09:01:26 sborrill Exp $	*/
 
 /*-
  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
@@ -73,7 +73,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pci_machdep.c,v 1.65 2014/01/27 23:11:50 jakllsch Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pci_machdep.c,v 1.66 2014/05/06 09:01:26 sborrill Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -526,6 +526,7 @@ pci_mode_detect(void)
 	int i;
 	pcireg_t idreg;
 	extern char cpu_brand_string[];
+	const char *system_vendor, *system_product;
 
 	if (pci_mode != -1)
 		return pci_mode;
@@ -555,7 +556,13 @@ pci_mode_detect(void)
 			return (pci_mode);
 		}
 	}
-        if (memcmp(cpu_brand_string, "QEMU", 4) == 0) {
+
+	system_vendor = pmf_get_platform("system-vendor");
+	system_product = pmf_get_platform("system-product");
+        if (memcmp(cpu_brand_string, "QEMU", 4) == 0 ||
+	    (system_vendor != NULL && system_product != NULL &&
+	     !strcmp(system_vendor, "Xen") &&
+	     !strcmp(system_product, "HVM domU"))) {
 		/* PR 45671, https://bugs.launchpad.net/qemu/+bug/897771 */
 #ifdef DEBUG
 		printf("forcing PCI mode 1 for QEMU\n");