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.0 will be re-assigned to 00:01.0.
+ second device at 02:1a.1 will be re-assigned to 00:01.1.
config XEN_PCIDEV_BACKEND_PASS
bool "Passthrough"
which depend on finding their hardward in certain bus/slot
locations.
+config XEN_PCIDEV_BACKEND_SLOT
+ bool "Slot"
+ ---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.
+ Contrary to the virtual PCI backend, a function becomes a new slot.
+ For example, a device at 03:05.2 will be re-assigned to 00:00.0. A
+ second device at 02:1a.1 will be re-assigned to 00:01.0.
+
endchoice
config XEN_PCIDEV_BE_DEBUG
--- /dev/null
+/*
+ * PCI Backend - Provides a Virtual PCI bus (with real devices)
+ * to the frontend
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil> (vpci.c)
+ * Author: Tristan Gingold <tristan.gingold@bull.net>, from vpci.c
+ */
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include "pciback.h"
+
+/* There are at most 32 slots in a pci bus. */
+#define PCI_SLOT_MAX 32
+
+#define PCI_BUS_NBR 2
+
+struct slot_dev_data {
+ /* Access to dev_list must be protected by lock */
+ struct pci_dev *slots[PCI_BUS_NBR][PCI_SLOT_MAX];
+ spinlock_t lock;
+};
+
+struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev,
+ unsigned int domain, unsigned int bus,
+ unsigned int devfn)
+{
+ struct pci_dev *dev = NULL;
+ struct slot_dev_data *slot_dev = pdev->pci_dev_data;
+ unsigned long flags;
+
+ if (domain != 0 || PCI_FUNC(devfn) != 0)
+ return NULL;
+
+ if (PCI_SLOT(devfn) >= PCI_SLOT_MAX || bus >= PCI_BUS_NBR)
+ return NULL;
+
+ spin_lock_irqsave(&slot_dev->lock, flags);
+ dev = slot_dev->slots[bus][PCI_SLOT(devfn)];
+ spin_unlock_irqrestore(&slot_dev->lock, flags);
+
+ return dev;
+}
+
+int pciback_add_pci_dev(struct pciback_device *pdev, struct pci_dev *dev)
+{
+ int err = 0, slot, bus;
+ struct slot_dev_data *slot_dev = pdev->pci_dev_data;
+ unsigned long flags;
+
+ if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
+ err = -EFAULT;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Can't export bridges on the virtual PCI bus");
+ goto out;
+ }
+
+ spin_lock_irqsave(&slot_dev->lock, flags);
+
+ /* Assign to a new slot on the virtual PCI bus */
+ for (bus = 0; bus < PCI_BUS_NBR; bus++)
+ for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+ if (slot_dev->slots[bus][slot] == NULL) {
+ printk(KERN_INFO
+ "pciback: slot: %s: assign to virtual slot %d, bus %d\n",
+ pci_name(dev), slot, bus);
+ slot_dev->slots[bus][slot] = dev;
+ goto unlock;
+ }
+ }
+
+ err = -ENOMEM;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "No more space on root virtual PCI bus");
+
+ unlock:
+ spin_unlock_irqrestore(&slot_dev->lock, flags);
+ out:
+ return err;
+}
+
+void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev)
+{
+ int slot, bus;
+ struct slot_dev_data *slot_dev = pdev->pci_dev_data;
+ struct pci_dev *found_dev = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&slot_dev->lock, flags);
+
+ for (bus = 0; bus < PCI_BUS_NBR; bus++)
+ for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+ if (slot_dev->slots[bus][slot] == dev) {
+ slot_dev->slots[bus][slot] = NULL;
+ found_dev = dev;
+ goto out;
+ }
+ }
+
+ out:
+ spin_unlock_irqrestore(&slot_dev->lock, flags);
+
+ if (found_dev)
+ pcistub_put_pci_dev(found_dev);
+}
+
+int pciback_init_devices(struct pciback_device *pdev)
+{
+ int slot, bus;
+ struct slot_dev_data *slot_dev;
+
+ slot_dev = kmalloc(sizeof(*slot_dev), GFP_KERNEL);
+ if (!slot_dev)
+ return -ENOMEM;
+
+ spin_lock_init(&slot_dev->lock);
+
+ for (bus = 0; bus < PCI_BUS_NBR; bus++)
+ for (slot = 0; slot < PCI_SLOT_MAX; slot++)
+ slot_dev->slots[bus][slot] = NULL;
+
+ pdev->pci_dev_data = slot_dev;
+
+ return 0;
+}
+
+int pciback_publish_pci_roots(struct pciback_device *pdev,
+ publish_pci_root_cb publish_cb)
+{
+ /* The Virtual PCI bus has only one root */
+ return publish_cb(pdev, 0, 0);
+}
+
+void pciback_release_devices(struct pciback_device *pdev)
+{
+ int slot, bus;
+ struct slot_dev_data *slot_dev = pdev->pci_dev_data;
+ struct pci_dev *dev;
+
+ for (bus = 0; bus < PCI_BUS_NBR; bus++)
+ for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+ dev = slot_dev->slots[bus][slot];
+ if (dev != NULL)
+ pcistub_put_pci_dev(dev);
+ }
+
+ kfree(slot_dev);
+ pdev->pci_dev_data = NULL;
+}
projects / xen.git / commitdiff