[Xen-devel] [PATCH 4/6] [pciback] Register the owner (domain) of the PCI device.

Konrad Rzeszutek Wilk
Wed, 09 Dec 2009 16:29:31 -0000

When the front-end and back-end start negotiating we register
the domain that will use the PCI device. Furthermore during shutdown
of guest or unbinding of the PCI device (and unloading of module)
from pciback we unregister the domain owner.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/xen/pciback/pci_stub.c |    3 +++
 drivers/xen/pciback/xenbus.c   |   12 ++++++++++++
 2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/xen/pciback/pci_stub.c b/drivers/xen/pciback/pci_stub.c
index c65c7c1..00018c1 100644
--- a/drivers/xen/pciback/pci_stub.c
+++ b/drivers/xen/pciback/pci_stub.c
@@ -14,6 +14,7 @@
 #include <linux/wait.h>
 #include <asm/atomic.h>
 #include <xen/events.h>
+#include <asm/xen/pci.h>
 #include "pciback.h"
 #include "conf_space.h"
 #include "conf_space_quirks.h"
@@ -87,6 +88,8 @@ static void pcistub_device_release(struct kref *kref)

 	dev_dbg(&psdev->dev->dev, "pcistub_device_release\n");

+	unregister_device_owner(psdev->dev);
+
 	/* Clean-up the device */
 	pciback_reset_device(psdev->dev);
 	pciback_config_free_dyn_fields(psdev->dev);
diff --git a/drivers/xen/pciback/xenbus.c b/drivers/xen/pciback/xenbus.c
index efec585..86acae3 100644
--- a/drivers/xen/pciback/xenbus.c
+++ b/drivers/xen/pciback/xenbus.c
@@ -10,6 +10,7 @@
 #include <linux/workqueue.h>
 #include <xen/xenbus.h>
 #include <xen/events.h>
+#include <asm/xen/pci.h>
 #include <linux/workqueue.h>
 #include "pciback.h"

@@ -221,6 +222,14 @@ static int pciback_export_device(struct pciback_device
*pdev,
 	if (err)
 		goto out;

+	dev_info(&dev->dev, "registering for %d\n",
pdev->xdev->otherend_id);
+	if (register_device_owner(dev, pdev->xdev->otherend_id) != 0) {
+		dev_err(&dev->dev, "device has been assigned to another " \
+			"domain! Over-writting the ownership, but beware.\n");
+		unregister(dev);
+		register_device_owner(dev, pdev->xdev->otherend_id);
+	}
+
 	/* TODO: It''d be nice to export a bridge and have all of its children
 	 * get exported with it. This may be best done in xend (which will
 	 * have to calculate resource usage anyway) but we probably want to
@@ -251,6 +260,9 @@ static int pciback_remove_device(struct pciback_device
*pdev,
 		goto out;
 	}

+	dev_db(&dev->dev, "unregistering for %d\n",
pdev->xdev->otherend_id);
+	unregister_device_owner(dev);
+
 	pciback_release_pci_dev(pdev, dev);