v4.19.13 snapshot.
diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
new file mode 100644
index 0000000..184b369
--- /dev/null
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -0,0 +1,221 @@
+/******************************************************************************
+ * 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/export.h>
+
+#include <xen/platform_pci.h>
+#include "xen-ops.h"
+
+#define XEN_PLATFORM_ERR_MAGIC -1
+#define XEN_PLATFORM_ERR_PROTOCOL -2
+#define XEN_PLATFORM_ERR_BLACKLIST -3
+
+#ifdef CONFIG_XEN_PVHVM
+/* store the value of xen_emul_unplug after the unplug is done */
+static int xen_platform_pci_unplug;
+static int xen_emul_unplug;
+
+static int 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\n");
+ return XEN_PLATFORM_ERR_PROTOCOL;
+ }
+
+ return 0;
+}
+
+bool xen_has_pv_devices(void)
+{
+ if (!xen_domain())
+ return false;
+
+ /* PV and PVH domains always have them. */
+ if (xen_pv_domain() || xen_pvh_domain())
+ return true;
+
+ /* And user has xen_platform_pci=0 set in guest config as
+ * driver did not modify the value. */
+ if (xen_platform_pci_unplug == 0)
+ return false;
+
+ if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER)
+ return false;
+
+ if (xen_platform_pci_unplug & XEN_UNPLUG_ALL)
+ return true;
+
+ /* This is an odd one - we are going to run legacy
+ * and PV drivers at the same time. */
+ if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
+ return true;
+
+ /* And the caller has to follow with xen_pv_{disk,nic}_devices
+ * to be certain which driver can load. */
+ return false;
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_devices);
+
+static bool __xen_has_pv_device(int state)
+{
+ /* HVM domains might or might not */
+ if (xen_hvm_domain() && (xen_platform_pci_unplug & state))
+ return true;
+
+ return xen_has_pv_devices();
+}
+
+bool xen_has_pv_nic_devices(void)
+{
+ return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL);
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices);
+
+bool xen_has_pv_disk_devices(void)
+{
+ return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS |
+ XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL);
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices);
+
+/*
+ * This one is odd - it determines whether you want to run PV _and_
+ * legacy (IDE) drivers together. This combination is only possible
+ * under HVM.
+ */
+bool xen_has_pv_and_legacy_disk_devices(void)
+{
+ if (!xen_domain())
+ return false;
+
+ /* N.B. This is only ever used in HVM mode */
+ if (xen_pv_domain())
+ return false;
+
+ if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices);
+
+void xen_unplug_emulated_devices(void)
+{
+ int r;
+
+ /* PVH guests don't have emulated devices. */
+ if (xen_pvh_domain())
+ return;
+
+ /* user explicitly requested no unplug */
+ if (xen_emul_unplug & XEN_UNPLUG_NEVER)
+ return;
+ /* 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 host does
+ * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC)
+ * but the user told us that unplugging is unnecessary. */
+ if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
+ (xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)))
+ 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_UNNECESSARY))
+ 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, "unnecessary", l))
+ xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY;
+ else if (!strncmp(p, "never", l))
+ xen_emul_unplug |= XEN_UNPLUG_NEVER;
+ 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);
+#endif