xen/pciback: Support pci_reset_function, aka FLR or D3 support.
We use the __pci_reset_function_locked to perform the action.
Also on attaching ("bind") and detaching ("unbind") we save and
restore the configuration states. When the device is disconnected
from a guest we use the "pci_reset_function" to also reset the
device before being passed to another guest.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 7944a17..6f63b9d 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -85,19 +85,34 @@
static void pcistub_device_release(struct kref *kref)
{
struct pcistub_device *psdev;
+ struct xen_pcibk_dev_data *dev_data;
psdev = container_of(kref, struct pcistub_device, kref);
+ dev_data = pci_get_drvdata(psdev->dev);
dev_dbg(&psdev->dev->dev, "pcistub_device_release\n");
xen_unregister_device_domain_owner(psdev->dev);
- /* Clean-up the device */
+ /* Call the reset function which does not take lock as this
+ * is called from "unbind" which takes a device_lock mutex.
+ */
+ __pci_reset_function_locked(psdev->dev);
+ if (pci_load_and_free_saved_state(psdev->dev,
+ &dev_data->pci_saved_state)) {
+ dev_dbg(&psdev->dev->dev, "Could not reload PCI state\n");
+ } else
+ pci_restore_state(psdev->dev);
+
+ /* Disable the device */
xen_pcibk_reset_device(psdev->dev);
+
+ kfree(dev_data);
+ pci_set_drvdata(psdev->dev, NULL);
+
+ /* Clean-up the device */
xen_pcibk_config_free_dyn_fields(psdev->dev);
xen_pcibk_config_free_dev(psdev->dev);
- kfree(pci_get_drvdata(psdev->dev));
- pci_set_drvdata(psdev->dev, NULL);
psdev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
pci_dev_put(psdev->dev);
@@ -231,7 +246,17 @@
/* Cleanup our device
* (so it's ready for the next domain)
*/
+
+ /* This is OK - we are running from workqueue context
+ * and want to inhibit the user from fiddling with 'reset'
+ */
+ pci_reset_function(dev);
+ pci_restore_state(psdev->dev);
+
+ /* This disables the device. */
xen_pcibk_reset_device(found_psdev->dev);
+
+ /* And cleanup up our emulated fields. */
xen_pcibk_config_free_dyn_fields(found_psdev->dev);
xen_pcibk_config_reset_dev(found_psdev->dev);
@@ -328,6 +353,16 @@
if (err)
goto config_release;
+ dev_dbg(&dev->dev, "reseting (FLR, D3, etc) the device\n");
+ __pci_reset_function_locked(dev);
+
+ /* We need the device active to save the state. */
+ dev_dbg(&dev->dev, "save state of device\n");
+ pci_save_state(dev);
+ dev_data->pci_saved_state = pci_store_saved_state(dev);
+ if (!dev_data->pci_saved_state)
+ dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
+
/* Now disable the device (this also ensures some private device
* data is setup before we export)
*/