x86: Unplug emulated disks and nics.
Add a xen_emul_unplug command line option to the kernel to unplug
xen emulated disks and nics.
Set the default value of xen_emul_unplug depending on whether or
not the Xen PV frontends and the Xen platform PCI driver have
been compiled for this kernel (modules or built-in are both OK).
The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM
even if the host platform doesn't support unplug.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 82ed403..6eb2989 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -48,6 +48,7 @@
#include <xen/grant_table.h>
#include <xen/events.h>
#include <xen/page.h>
+#include <xen/platform_pci.h>
#include <xen/interface/grant_table.h>
#include <xen/interface/io/blkif.h>
@@ -737,6 +738,22 @@
}
}
+ /* no unplug has been done: do not hook devices != xen vbds */
+ if (xen_hvm_domain() && (xen_platform_pci_unplug & XEN_UNPLUG_IGNORE)) {
+ int major;
+
+ if (!VDEV_IS_EXTENDED(vdevice))
+ major = BLKIF_MAJOR(vdevice);
+ else
+ major = XENVBD_MAJOR;
+
+ if (major != XENVBD_MAJOR) {
+ printk(KERN_INFO
+ "%s: HVM does not support vbd %d as xen block device\n",
+ __FUNCTION__, vdevice);
+ return -ENODEV;
+ }
+ }
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index bdb44f2..c01b5dd 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/pci.h>
+#include <xen/platform_pci.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
#include <xen/events.h>
@@ -195,6 +196,11 @@
static int __init platform_pci_module_init(void)
{
+ /* no unplug has been done, IGNORE hasn't been specified: just
+ * return now */
+ if (!xen_platform_pci_unplug)
+ return -ENODEV;
+
return pci_register_driver(&platform_driver);
}
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index a9e83c4..37e8894 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -56,6 +56,7 @@
#include <xen/events.h>
#include <xen/page.h>
+#include <xen/platform_pci.h>
#include <xen/hvm.h>
#include "xenbus_comms.h"
@@ -977,6 +978,9 @@
#ifndef MODULE
static int __init boot_wait_for_devices(void)
{
+ if (xen_hvm_domain() && !xen_platform_pci_unplug)
+ return -ENODEV;
+
ready_to_wait_for_devices = 1;
wait_for_devices(NULL);
return 0;