--- /dev/null
+/*
+ * PCI Backend - Provides restricted access to the real PCI bus topology
+ * to the frontend
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include "pciback.h"
+
+struct passthrough_dev_data {
+ /* Access to dev_list must be protected by lock */
+ struct list_head dev_list;
+ struct mutex lock;
+};
+
+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;
+ struct pci_dev *dev = NULL;
+
+ mutex_lock(&dev_data->lock);
+
+ list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
+ if (domain == (unsigned int)pci_domain_nr(dev_entry->dev->bus)
+ && bus == (unsigned int)dev_entry->dev->bus->number
+ && devfn == dev_entry->dev->devfn) {
+ dev = dev_entry->dev;
+ break;
+ }
+ }
+
+ mutex_unlock(&dev_data->lock);
+
+ return dev;
+}
+
+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;
+ unsigned int domain, bus, devfn;
+ int err;
+
+ dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
+ if (!dev_entry)
+ return -ENOMEM;
+ dev_entry->dev = dev;
+
+ mutex_lock(&dev_data->lock);
+ list_add_tail(&dev_entry->list, &dev_data->dev_list);
+ mutex_unlock(&dev_data->lock);
+
+ /* Publish this device. */
+ domain = (unsigned int)pci_domain_nr(dev->bus);
+ bus = (unsigned int)dev->bus->number;
+ devfn = dev->devfn;
+ err = publish_cb(pdev, domain, bus, devfn, devid);
+
+ return err;
+}
+
+static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
+ struct pci_dev *dev, bool lock)
+{
+ struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
+ struct pci_dev_entry *dev_entry, *t;
+ struct pci_dev *found_dev = NULL;
+
+ mutex_lock(&dev_data->lock);
+
+ list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
+ if (dev_entry->dev == dev) {
+ list_del(&dev_entry->list);
+ found_dev = dev_entry->dev;
+ kfree(dev_entry);
+ }
+ }
+
+ mutex_unlock(&dev_data->lock);
+
+ if (found_dev) {
+ if (lock)
+ device_lock(&found_dev->dev);
+ pcistub_put_pci_dev(found_dev);
+ if (lock)
+ device_unlock(&found_dev->dev);
+ }
+}
+
+static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
+{
+ struct passthrough_dev_data *dev_data;
+
+ dev_data = kmalloc(sizeof(*dev_data), GFP_KERNEL);
+ if (!dev_data)
+ return -ENOMEM;
+
+ mutex_init(&dev_data->lock);
+
+ INIT_LIST_HEAD(&dev_data->dev_list);
+
+ pdev->pci_dev_data = dev_data;
+
+ return 0;
+}
+
+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;
+ struct pci_dev_entry *dev_entry, *e;
+ struct pci_dev *dev;
+ int found;
+ unsigned int domain, bus;
+
+ mutex_lock(&dev_data->lock);
+
+ list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
+ /* Only publish this device as a root if none of its
+ * parent bridges are exported
+ */
+ found = 0;
+ dev = dev_entry->dev->bus->self;
+ for (; !found && dev != NULL; dev = dev->bus->self) {
+ list_for_each_entry(e, &dev_data->dev_list, list) {
+ if (dev == e->dev) {
+ found = 1;
+ break;
+ }
+ }
+ }
+
+ domain = (unsigned int)pci_domain_nr(dev_entry->dev->bus);
+ bus = (unsigned int)dev_entry->dev->bus->number;
+
+ if (!found) {
+ err = publish_root_cb(pdev, domain, bus);
+ if (err)
+ break;
+ }
+ }
+
+ mutex_unlock(&dev_data->lock);
+
+ return err;
+}
+
+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;
+
+ list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
+ struct pci_dev *dev = dev_entry->dev;
+ list_del(&dev_entry->list);
+ device_lock(&dev->dev);
+ pcistub_put_pci_dev(dev);
+ device_unlock(&dev->dev);
+ kfree(dev_entry);
+ }
+
+ kfree(dev_data);
+ pdev->pci_dev_data = NULL;
+}
+
+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;
+}
+
+const 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,
+};
Code Review / kvmfornfv.git / blobdiff