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210 lines
5.5 KiB
210 lines
5.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/****************************************************************************** |
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* platform-pci-unplug.c |
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* |
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* Xen platform PCI device driver |
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* Copyright (c) 2010, Citrix |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/export.h> |
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#include <xen/xen.h> |
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#include <xen/platform_pci.h> |
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#include "xen-ops.h" |
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#define XEN_PLATFORM_ERR_MAGIC -1 |
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#define XEN_PLATFORM_ERR_PROTOCOL -2 |
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#define XEN_PLATFORM_ERR_BLACKLIST -3 |
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/* store the value of xen_emul_unplug after the unplug is done */ |
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static int xen_platform_pci_unplug; |
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static int xen_emul_unplug; |
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static int check_platform_magic(void) |
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{ |
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short magic; |
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char protocol; |
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magic = inw(XEN_IOPORT_MAGIC); |
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if (magic != XEN_IOPORT_MAGIC_VAL) { |
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pr_err("Xen Platform PCI: unrecognised magic value\n"); |
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return XEN_PLATFORM_ERR_MAGIC; |
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} |
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protocol = inb(XEN_IOPORT_PROTOVER); |
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pr_debug("Xen Platform PCI: I/O protocol version %d\n", |
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protocol); |
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switch (protocol) { |
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case 1: |
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outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM); |
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outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER); |
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if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) { |
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pr_err("Xen Platform: blacklisted by host\n"); |
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return XEN_PLATFORM_ERR_BLACKLIST; |
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} |
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break; |
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default: |
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pr_warn("Xen Platform PCI: unknown I/O protocol version\n"); |
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return XEN_PLATFORM_ERR_PROTOCOL; |
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} |
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return 0; |
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} |
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bool xen_has_pv_devices(void) |
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{ |
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if (!xen_domain()) |
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return false; |
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/* PV and PVH domains always have them. */ |
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if (xen_pv_domain() || xen_pvh_domain()) |
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return true; |
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/* And user has xen_platform_pci=0 set in guest config as |
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* driver did not modify the value. */ |
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if (xen_platform_pci_unplug == 0) |
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return false; |
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if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER) |
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return false; |
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if (xen_platform_pci_unplug & XEN_UNPLUG_ALL) |
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return true; |
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/* This is an odd one - we are going to run legacy |
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* and PV drivers at the same time. */ |
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if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) |
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return true; |
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/* And the caller has to follow with xen_pv_{disk,nic}_devices |
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* to be certain which driver can load. */ |
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return false; |
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} |
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EXPORT_SYMBOL_GPL(xen_has_pv_devices); |
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static bool __xen_has_pv_device(int state) |
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{ |
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/* HVM domains might or might not */ |
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if (xen_hvm_domain() && (xen_platform_pci_unplug & state)) |
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return true; |
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return xen_has_pv_devices(); |
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} |
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bool xen_has_pv_nic_devices(void) |
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{ |
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return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL); |
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} |
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EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices); |
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bool xen_has_pv_disk_devices(void) |
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{ |
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return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS | |
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XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL); |
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} |
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EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices); |
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/* |
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* This one is odd - it determines whether you want to run PV _and_ |
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* legacy (IDE) drivers together. This combination is only possible |
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* under HVM. |
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*/ |
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bool xen_has_pv_and_legacy_disk_devices(void) |
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{ |
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if (!xen_domain()) |
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return false; |
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/* N.B. This is only ever used in HVM mode */ |
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if (xen_pv_domain()) |
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return false; |
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if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) |
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return true; |
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return false; |
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} |
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EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices); |
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void xen_unplug_emulated_devices(void) |
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{ |
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int r; |
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/* PVH guests don't have emulated devices. */ |
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if (xen_pvh_domain()) |
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return; |
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/* user explicitly requested no unplug */ |
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if (xen_emul_unplug & XEN_UNPLUG_NEVER) |
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return; |
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/* check the version of the xen platform PCI device */ |
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r = check_platform_magic(); |
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/* If the version matches enable the Xen platform PCI driver. |
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* Also enable the Xen platform PCI driver if the host does |
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* not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC) |
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* but the user told us that unplugging is unnecessary. */ |
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if (r && !(r == XEN_PLATFORM_ERR_MAGIC && |
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(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))) |
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return; |
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/* Set the default value of xen_emul_unplug depending on whether or |
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* not the Xen PV frontends and the Xen platform PCI driver have |
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* been compiled for this kernel (modules or built-in are both OK). */ |
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if (!xen_emul_unplug) { |
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if (xen_must_unplug_nics()) { |
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pr_info("Netfront and the Xen platform PCI driver have " |
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"been compiled for this kernel: unplug emulated NICs.\n"); |
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xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; |
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} |
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if (xen_must_unplug_disks()) { |
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pr_info("Blkfront and the Xen platform PCI driver have " |
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"been compiled for this kernel: unplug emulated disks.\n" |
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"You might have to change the root device\n" |
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"from /dev/hd[a-d] to /dev/xvd[a-d]\n" |
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"in your root= kernel command line option\n"); |
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xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; |
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} |
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} |
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/* Now unplug the emulated devices */ |
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if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)) |
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outw(xen_emul_unplug, XEN_IOPORT_UNPLUG); |
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xen_platform_pci_unplug = xen_emul_unplug; |
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} |
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static int __init parse_xen_emul_unplug(char *arg) |
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{ |
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char *p, *q; |
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int l; |
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for (p = arg; p; p = q) { |
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q = strchr(p, ','); |
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if (q) { |
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l = q - p; |
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q++; |
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} else { |
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l = strlen(p); |
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} |
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if (!strncmp(p, "all", l)) |
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xen_emul_unplug |= XEN_UNPLUG_ALL; |
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else if (!strncmp(p, "ide-disks", l)) |
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xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; |
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else if (!strncmp(p, "aux-ide-disks", l)) |
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xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS; |
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else if (!strncmp(p, "nics", l)) |
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xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; |
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else if (!strncmp(p, "unnecessary", l)) |
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xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY; |
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else if (!strncmp(p, "never", l)) |
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xen_emul_unplug |= XEN_UNPLUG_NEVER; |
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else |
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pr_warn("unrecognised option '%s' " |
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"in parameter 'xen_emul_unplug'\n", p); |
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} |
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return 0; |
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} |
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early_param("xen_emul_unplug", parse_xen_emul_unplug);
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