1 files changed, 91 insertions, 11 deletions

diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
index 554c002a1e1..a8261716d58 100644
--- a/arch/x86/xen/platform-pci-unplug.c
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -24,18 +24,18 @@
 #include <linux/module.h>
 
 #include <xen/platform_pci.h>
+#include "xen-ops.h"
 
 #define XEN_PLATFORM_ERR_MAGIC -1
 #define XEN_PLATFORM_ERR_PROTOCOL -2
 #define XEN_PLATFORM_ERR_BLACKLIST -3
 
-/* store the value of xen_emul_unplug after the unplug is done */
-int xen_platform_pci_unplug;
-EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
 #ifdef CONFIG_XEN_PVHVM
+/* store the value of xen_emul_unplug after the unplug is done */
+static int xen_platform_pci_unplug;
 static int xen_emul_unplug;
 
-static int __init check_platform_magic(void)
+static int check_platform_magic(void)
 {
 	short magic;
 	char protocol;
@@ -68,17 +68,95 @@ static int __init check_platform_magic(void)
 	return 0;
 }
 
-void __init xen_unplug_emulated_devices(void)
+bool xen_has_pv_devices()
+{
+	if (!xen_domain())
+		return false;
+
+	/* PV domains always have them. */
+	if (xen_pv_domain())
+		return true;
+
+	/* And user has xen_platform_pci=0 set in guest config as
+	 * driver did not modify the value. */
+	if (xen_platform_pci_unplug == 0)
+		return false;
+
+	if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER)
+		return false;
+
+	if (xen_platform_pci_unplug & XEN_UNPLUG_ALL)
+		return true;
+
+	/* This is an odd one - we are going to run legacy
+	 * and PV drivers at the same time. */
+	if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
+		return true;
+
+	/* And the caller has to follow with xen_pv_{disk,nic}_devices
+	 * to be certain which driver can load. */
+	return false;
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_devices);
+
+static bool __xen_has_pv_device(int state)
+{
+	/* HVM domains might or might not */
+	if (xen_hvm_domain() && (xen_platform_pci_unplug & state))
+		return true;
+
+	return xen_has_pv_devices();
+}
+
+bool xen_has_pv_nic_devices(void)
+{
+	return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL);
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices);
+
+bool xen_has_pv_disk_devices(void)
+{
+	return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS |
+				   XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL);
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices);
+
+/*
+ * This one is odd - it determines whether you want to run PV _and_
+ * legacy (IDE) drivers together. This combination is only possible
+ * under HVM.
+ */
+bool xen_has_pv_and_legacy_disk_devices(void)
+{
+	if (!xen_domain())
+		return false;
+
+	/* N.B. This is only ever used in HVM mode */
+	if (xen_pv_domain())
+		return false;
+
+	if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices);
+
+void xen_unplug_emulated_devices(void)
 {
 	int r;
 
+	/* user explicitly requested no unplug */
+	if (xen_emul_unplug & XEN_UNPLUG_NEVER)
+		return;
 	/* check the version of the xen platform PCI device */
 	r = check_platform_magic();
 	/* If the version matches enable the Xen platform PCI driver.
-	 * Also enable the Xen platform PCI driver if the version is really old
-	 * and the user told us to ignore it. */
+	 * Also enable the Xen platform PCI driver if the host does
+	 * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC)
+	 * but the user told us that unplugging is unnecessary. */
 	if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
-			(xen_emul_unplug & XEN_UNPLUG_IGNORE)))
+			(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)))
 		return;
 	/* Set the default value of xen_emul_unplug depending on whether or
 	 * not the Xen PV frontends and the Xen platform PCI driver have
@@ -99,7 +177,7 @@ void __init xen_unplug_emulated_devices(void)
 		}
 	}
 	/* Now unplug the emulated devices */
-	if (!(xen_emul_unplug & XEN_UNPLUG_IGNORE))
+	if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))
 		outw(xen_emul_unplug, XEN_IOPORT_UNPLUG);
 	xen_platform_pci_unplug = xen_emul_unplug;
 }
@@ -125,8 +203,10 @@ static int __init parse_xen_emul_unplug(char *arg)
 			xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS;
 		else if (!strncmp(p, "nics", l))
 			xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
-		else if (!strncmp(p, "ignore", l))
-			xen_emul_unplug |= XEN_UNPLUG_IGNORE;
+		else if (!strncmp(p, "unnecessary", l))
+			xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY;
+		else if (!strncmp(p, "never", l))
+			xen_emul_unplug |= XEN_UNPLUG_NEVER;
 		else
 			printk(KERN_WARNING "unrecognised option '%s' "
 				 "in parameter 'xen_emul_unplug'\n", p);