1 files changed, 74 insertions, 0 deletions

diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
index 0a7852483ffe..ab84ac198a9a 100644
--- a/arch/x86/xen/platform-pci-unplug.c
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -69,6 +69,80 @@ static int check_platform_magic(void)
         return 0;
 }
 
+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;