6 files changed, 166 insertions, 72 deletions

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 0b6989f92041..9b700b4a987a 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -109,34 +109,22 @@ config XEN_PCIDEV_BACKEND
         tristate "Xen PCI-device backend driver"
         depends on PCI && X86 && XEN
         depends on XEN_BACKEND
+        default m
         help
           The PCI device backend driver allows the kernel to export arbitrary
           PCI devices to other guests. If you select this to be a module, you
           will need to make sure no other driver has bound to the device(s)
           you want to make visible to other guests.
 
-choice
-        prompt "PCI Backend Mode"
-        depends on XEN_PCIDEV_BACKEND
-
-config XEN_PCIDEV_BACKEND_VPCI
-        bool "Virtual PCI"
-        help
-          This PCI Backend hides the true PCI topology and makes the frontend
-          think there is a single PCI bus with only the exported devices on it.
-          For example, a device at 03:05.0 will be re-assigned to 00:00.0. A
-          second device at 02:1a.1 will be re-assigned to 00:01.1.
-
-config XEN_PCIDEV_BACKEND_PASS
-        bool "Passthrough"
-        help
-          This PCI Backend provides a real view of the PCI topology to the
-          frontend (for example, a device at 06:01.b will still appear at
-          06:01.b to the frontend). This is similar to how Xen 2.0.x exposed
-          PCI devices to its driver domains. This may be required for drivers
-          which depend on finding their hardward in certain bus/slot
-          locations.
+          The parameter "passthrough" allows you specify how you want the PCI
+          devices to appear in the guest. You can choose the default (0) where
+          PCI topology starts at 00.00.0, or (1) for passthrough if you want
+          the PCI devices topology appear the same as in the host.
 
-endchoice
+          The "hide" parameter (only applicable if backend driver is compiled
+          into the kernel) allows you to bind the PCI devices to this module
+          from the default device drivers. The argument is the list of PCI BDFs:
+          xen-pciback.hide=(03:00.0)(04:00.0)
 
+          If in doubt, say m.
 endmenu
diff --git a/drivers/xen/xen-pciback/Makefile b/drivers/xen/xen-pciback/Makefile
index 290396766f07..ffe0ad3438bd 100644
--- a/drivers/xen/xen-pciback/Makefile
+++ b/drivers/xen/xen-pciback/Makefile
@@ -3,6 +3,5 @@ obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback.o
 xen-pciback-y := pci_stub.o pciback_ops.o xenbus.o
 xen-pciback-y += conf_space.o conf_space_header.o \
                  conf_space_capability.o \
-                 conf_space_quirks.o
-xen-pciback-$(CONFIG_XEN_PCIDEV_BACKEND_VPCI) += vpci.o
-xen-pciback-$(CONFIG_XEN_PCIDEV_BACKEND_PASS) += passthrough.o
+                 conf_space_quirks.o vpci.o \
+                 passthrough.o
diff --git a/drivers/xen/xen-pciback/passthrough.c b/drivers/xen/xen-pciback/passthrough.c
index b451cb8dd2ff..1d32a9a42c01 100644
--- a/drivers/xen/xen-pciback/passthrough.c
+++ b/drivers/xen/xen-pciback/passthrough.c
@@ -16,9 +16,10 @@ struct passthrough_dev_data {
         spinlock_t lock;
 };
 
-struct pci_dev *xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
-                                      unsigned int domain, unsigned int bus,
-                                      unsigned int devfn)
+static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
+                                               unsigned int domain,
+                                               unsigned int bus,
+                                               unsigned int devfn)
 {
         struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
         struct pci_dev_entry *dev_entry;
@@ -41,8 +42,9 @@ struct pci_dev *xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
         return dev;
 }
 
-int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *dev,
-                          int devid, publish_pci_dev_cb publish_cb)
+static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
+                                   struct pci_dev *dev,
+                                   int devid, publish_pci_dev_cb publish_cb)
 {
         struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
         struct pci_dev_entry *dev_entry;
@@ -68,8 +70,8 @@ int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *dev,
         return err;
 }
 
-void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
-                               struct pci_dev *dev)
+static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
+                                        struct pci_dev *dev)
 {
         struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
         struct pci_dev_entry *dev_entry, *t;
@@ -92,7 +94,7 @@ void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
                 pcistub_put_pci_dev(found_dev);
 }
 
-int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
+static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
 {
         struct passthrough_dev_data *dev_data;
 
@@ -109,8 +111,8 @@ int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
         return 0;
 }
 
-int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
-                                publish_pci_root_cb publish_root_cb)
+static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
+                                         publish_pci_root_cb publish_root_cb)
 {
         int err = 0;
         struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
@@ -154,7 +156,7 @@ int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
         return err;
 }
 
-void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
+static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
 {
         struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
         struct pci_dev_entry *dev_entry, *t;
@@ -169,13 +171,24 @@ void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
         pdev->pci_dev_data = NULL;
 }
 
-int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
-                               struct xen_pcibk_device *pdev,
-                               unsigned int *domain, unsigned int *bus,
-                               unsigned int *devfn)
+static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
+                                        struct xen_pcibk_device *pdev,
+                                        unsigned int *domain, unsigned int *bus,
+                                        unsigned int *devfn)
 {
         *domain = pci_domain_nr(pcidev->bus);
         *bus = pcidev->bus->number;
         *devfn = pcidev->devfn;
         return 1;
 }
+
+struct xen_pcibk_backend xen_pcibk_passthrough_backend = {
+        .name           = "passthrough",
+        .init           = __xen_pcibk_init_devices,
+        .free           = __xen_pcibk_release_devices,
+        .find           = __xen_pcibk_get_pcifront_dev,
+        .publish        = __xen_pcibk_publish_pci_roots,
+        .release        = __xen_pcibk_release_pci_dev,
+        .add            = __xen_pcibk_add_pci_dev,
+        .get            = __xen_pcibk_get_pci_dev,
+};
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index 427b7fd01356..a0e131a81503 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -83,30 +83,90 @@ typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev,
                                    unsigned int devfn, unsigned int devid);
 typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev,
                                     unsigned int domain, unsigned int bus);
-int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *dev,
-                          int devid, publish_pci_dev_cb publish_cb);
-void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
-                               struct pci_dev *dev);
-struct pci_dev *xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
-                                      unsigned int domain, unsigned int bus,
-                                      unsigned int devfn);
 
+/* Backend registration for the two types of BDF representation:
+ *  vpci - BDFs start at 00
+ *  passthrough - BDFs are exactly like in the host.
+ */
+struct xen_pcibk_backend {
+        char *name;
+        int (*init)(struct xen_pcibk_device *pdev);
+        void (*free)(struct xen_pcibk_device *pdev);
+        int (*find)(struct pci_dev *pcidev, struct xen_pcibk_device *pdev,
+                    unsigned int *domain, unsigned int *bus,
+                    unsigned int *devfn);
+        int (*publish)(struct xen_pcibk_device *pdev, publish_pci_root_cb cb);
+        void (*release)(struct xen_pcibk_device *pdev, struct pci_dev *dev);
+        int (*add)(struct xen_pcibk_device *pdev, struct pci_dev *dev,
+                   int devid, publish_pci_dev_cb publish_cb);
+        struct pci_dev *(*get)(struct xen_pcibk_device *pdev,
+                               unsigned int domain, unsigned int bus,
+                               unsigned int devfn);
+};
+
+extern struct xen_pcibk_backend xen_pcibk_vpci_backend;
+extern struct xen_pcibk_backend xen_pcibk_passthrough_backend;
+extern struct xen_pcibk_backend *xen_pcibk_backend;
+
+static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
+                                        struct pci_dev *dev,
+                                        int devid,
+                                        publish_pci_dev_cb publish_cb)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->add)
+                return xen_pcibk_backend->add(pdev, dev, devid, publish_cb);
+        return -1;
+};
+static inline void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
+                                             struct pci_dev *dev)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->free)
+                return xen_pcibk_backend->release(pdev, dev);
+};
+
+static inline struct pci_dev *
+xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain,
+                      unsigned int bus, unsigned int devfn)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->get)
+                return xen_pcibk_backend->get(pdev, domain, bus, devfn);
+        return NULL;
+};
 /**
 * Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk
 * before sending aer request to pcifront, so that guest could identify
 * device, coopearte with xen_pcibk to finish aer recovery job if device driver
 * has the capability
 */
-
-int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
-                               struct xen_pcibk_device *pdev,
-                               unsigned int *domain, unsigned int *bus,
-                               unsigned int *devfn);
-int xen_pcibk_init_devices(struct xen_pcibk_device *pdev);
-int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
-                                publish_pci_root_cb cb);
-void xen_pcibk_release_devices(struct xen_pcibk_device *pdev);
-
+static inline int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
+                                             struct xen_pcibk_device *pdev,
+                                             unsigned int *domain,
+                                             unsigned int *bus,
+                                             unsigned int *devfn)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->find)
+                return xen_pcibk_backend->find(pcidev, pdev, domain, bus,
+                                               devfn);
+        return -1;
+};
+static inline int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->init)
+                return xen_pcibk_backend->init(pdev);
+        return -1;
+};
+static inline int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
+                                              publish_pci_root_cb cb)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->publish)
+                return xen_pcibk_backend->publish(pdev, cb);
+        return -1;
+};
+static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
+{
+        if (xen_pcibk_backend && xen_pcibk_backend->free)
+                return xen_pcibk_backend->free(pdev);
+};
 /* Handles events from front-end */
 irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
 void xen_pcibk_do_op(struct work_struct *data);
diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c
index 7d5c192a1505..4a42cfb0959d 100644
--- a/drivers/xen/xen-pciback/vpci.c
+++ b/drivers/xen/xen-pciback/vpci.c
@@ -25,9 +25,10 @@ static inline struct list_head *list_first(struct list_head *head)
         return head->next;
 }
 
-struct pci_dev *xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
-                                      unsigned int domain, unsigned int bus,
-                                      unsigned int devfn)
+static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
+                                               unsigned int domain,
+                                               unsigned int bus,
+                                               unsigned int devfn)
 {
         struct pci_dev_entry *entry;
         struct pci_dev *dev = NULL;
@@ -63,8 +64,9 @@ static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
         return 0;
 }
 
-int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *dev,
-                          int devid, publish_pci_dev_cb publish_cb)
+static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
+                                   struct pci_dev *dev, int devid,
+                                   publish_pci_dev_cb publish_cb)
 {
         int err = 0, slot, func = -1;
         struct pci_dev_entry *t, *dev_entry;
@@ -137,8 +139,8 @@ out:
         return err;
 }
 
-void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
-                               struct pci_dev *dev)
+static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
+                                        struct pci_dev *dev)
 {
         int slot;
         struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
@@ -167,7 +169,7 @@ out:
                 pcistub_put_pci_dev(found_dev);
 }
 
-int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
+static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
 {
         int slot;
         struct vpci_dev_data *vpci_dev;
@@ -186,14 +188,14 @@ int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
         return 0;
 }
 
-int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
-                                publish_pci_root_cb publish_cb)
+static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
+                                         publish_pci_root_cb publish_cb)
 {
         /* The Virtual PCI bus has only one root */
         return publish_cb(pdev, 0, 0);
 }
 
-void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
+static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
 {
         int slot;
         struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
@@ -212,10 +214,10 @@ void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
         pdev->pci_dev_data = NULL;
 }
 
-int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
-                               struct xen_pcibk_device *pdev,
-                               unsigned int *domain, unsigned int *bus,
-                               unsigned int *devfn)
+static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
+                                        struct xen_pcibk_device *pdev,
+                                        unsigned int *domain, unsigned int *bus,
+                                        unsigned int *devfn)
 {
         struct pci_dev_entry *entry;
         struct pci_dev *dev = NULL;
@@ -244,3 +246,14 @@ int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
         spin_unlock_irqrestore(&vpci_dev->lock, flags);
         return found;
 }
+
+struct xen_pcibk_backend xen_pcibk_vpci_backend = {
+        .name           = "vpci",
+        .init           = __xen_pcibk_init_devices,
+        .free           = __xen_pcibk_release_devices,
+        .find           = __xen_pcibk_get_pcifront_dev,
+        .publish        = __xen_pcibk_publish_pci_roots,
+        .release        = __xen_pcibk_release_pci_dev,
+        .add            = __xen_pcibk_add_pci_dev,
+        .get            = __xen_pcibk_get_pci_dev,
+};
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 1e5ba85c0d33..206c4ce030bc 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -18,6 +18,21 @@
 #define INVALID_EVTCHN_IRQ  (-1)
 struct workqueue_struct *xen_pcibk_wq;
 
+static int __read_mostly passthrough;
+module_param(passthrough, bool, S_IRUGO);
+MODULE_PARM_DESC(passthrough,
+        "Option to specify how to export PCI topology to guest:\n"\
+        " 0 - (default) Hide the true PCI topology and makes the frontend\n"\
+        "   there is a single PCI bus with only the exported devices on it.\n"\
+        "   For example, a device at 03:05.0 will be re-assigned to 00:00.0\n"\
+        "   while second device at 02:1a.1 will be re-assigned to 00:01.1.\n"\
+        " 1 - Passthrough provides a real view of the PCI topology to the\n"\
+        "   frontend (for example, a device at 06:01.b will still appear at\n"\
+        "   06:01.b to the frontend). This is similar to how Xen 2.0.x\n"\
+        "   exposed PCI devices to its driver domains. This may be required\n"\
+        "   for drivers which depend on finding their hardward in certain\n"\
+        "   bus/slot locations.");
+
 static struct xen_pcibk_device *alloc_pdev(struct xenbus_device *xdev)
 {
         struct xen_pcibk_device *pdev;
@@ -710,6 +725,8 @@ static struct xenbus_driver xenbus_xen_pcibk_driver = {
         .otherend_changed       = xen_pcibk_frontend_changed,
 };
 
+struct xen_pcibk_backend *xen_pcibk_backend;
+
 int __init xen_pcibk_xenbus_register(void)
 {
         xen_pcibk_wq = create_workqueue("xen_pciback_workqueue");
@@ -718,6 +735,10 @@ int __init xen_pcibk_xenbus_register(void)
                         "xen_pciback_workqueue failed\n", __func__);
                 return -EFAULT;
         }
+        xen_pcibk_backend = &xen_pcibk_vpci_backend;
+        if (passthrough)
+                xen_pcibk_backend = &xen_pcibk_passthrough_backend;
+        pr_info(DRV_NAME ": backend is %s\n", xen_pcibk_backend->name);
         return xenbus_register_backend(&xenbus_xen_pcibk_driver);
 }