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/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
new file mode 100644
index 0000000..2f7f3fb
--- /dev/null
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -0,0 +1,135 @@
+/******************************************************************************
+ * platform-pci-unplug.c
+ *
+ * Xen platform PCI device driver
+ * Copyright (c) 2010, Citrix
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+#include <xen/platform_pci.h>
+
+#define XEN_PLATFORM_ERR_MAGIC -1
+#define XEN_PLATFORM_ERR_PROTOCOL -2
+#define XEN_PLATFORM_ERR_BLACKLIST -3
+
+/* store the value of xen_emul_unplug after the unplug is done */
+int xen_platform_pci_unplug;
+EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
+static int xen_emul_unplug;
+
+static int __init check_platform_magic(void)
+{
+ short magic;
+ char protocol;
+
+ magic = inw(XEN_IOPORT_MAGIC);
+ if (magic != XEN_IOPORT_MAGIC_VAL) {
+ printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n");
+ return XEN_PLATFORM_ERR_MAGIC;
+ }
+
+ protocol = inb(XEN_IOPORT_PROTOVER);
+
+ printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n",
+ protocol);
+
+ switch (protocol) {
+ case 1:
+ outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM);
+ outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER);
+ if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) {
+ printk(KERN_ERR "Xen Platform: blacklisted by host\n");
+ return XEN_PLATFORM_ERR_BLACKLIST;
+ }
+ break;
+ default:
+ printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
+ return XEN_PLATFORM_ERR_PROTOCOL;
+ }
+
+ return 0;
+}
+
+void __init xen_unplug_emulated_devices(void)
+{
+ int r;
+
+ /* check the version of the xen platform PCI device */
+ r = check_platform_magic();
+ /* If the version matches enable the Xen platform PCI driver.
+ * Also enable the Xen platform PCI driver if the version is really old
+ * and the user told us to ignore it. */
+ if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
+ (xen_emul_unplug & XEN_UNPLUG_IGNORE)))
+ return;
+ /* 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). */
+ if (!xen_emul_unplug) {
+ if (xen_must_unplug_nics()) {
+ printk(KERN_INFO "Netfront and the Xen platform PCI driver have "
+ "been compiled for this kernel: unplug emulated NICs.\n");
+ xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
+ }
+ if (xen_must_unplug_disks()) {
+ printk(KERN_INFO "Blkfront and the Xen platform PCI driver have "
+ "been compiled for this kernel: unplug emulated disks.\n"
+ "You might have to change the root device\n"
+ "from /dev/hd[a-d] to /dev/xvd[a-d]\n"
+ "in your root= kernel command line option\n");
+ xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
+ }
+ }
+ /* Now unplug the emulated devices */
+ if (!(xen_emul_unplug & XEN_UNPLUG_IGNORE))
+ outw(xen_emul_unplug, XEN_IOPORT_UNPLUG);
+ xen_platform_pci_unplug = xen_emul_unplug;
+}
+
+static int __init parse_xen_emul_unplug(char *arg)
+{
+ char *p, *q;
+ int l;
+
+ for (p = arg; p; p = q) {
+ q = strchr(p, ',');
+ if (q) {
+ l = q - p;
+ q++;
+ } else {
+ l = strlen(p);
+ }
+ if (!strncmp(p, "all", l))
+ xen_emul_unplug |= XEN_UNPLUG_ALL;
+ else if (!strncmp(p, "ide-disks", l))
+ xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
+ else if (!strncmp(p, "aux-ide-disks", l))
+ xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS;
+ else if (!strncmp(p, "nics", l))
+ xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
+ else if (!strncmp(p, "ignore", l))
+ xen_emul_unplug |= XEN_UNPLUG_IGNORE;
+ else
+ printk(KERN_WARNING "unrecognised option '%s' "
+ "in parameter 'xen_emul_unplug'\n", p);
+ }
+ return 0;
+}
+early_param("xen_emul_unplug", parse_xen_emul_unplug);