arch/x86/xen/platform-pci-unplug.c - kernel/lockdown - Git at Google

 /******************************************************************************
  * 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>
 #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");
 		return XEN_PLATFORM_ERR_PROTOCOL;
 	}

 	return 0;
 }

 bool xen_has_pv_devices()
 {
 	if (!xen_domain())
 		return false;

 	/* PV domains always have them. */
 	if (xen_pv_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;

 	/* 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
	/******************************************************************************
	* 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>
	#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");
	return XEN_PLATFORM_ERR_PROTOCOL;
	}

	return 0;
	}

	bool xen_has_pv_devices()
	{
	if (!xen_domain())
	return false;

	/* PV domains always have them. */
	if (xen_pv_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;

	/* 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