1dc7ce99b0
It is not immediately clear what this option causes to become ignored. The actual meaning is that it is not necessary to unplug the emulated devices to safely use the PV ones, even if the platform does not support the unplug protocol. (pressumably the user will only add this option if they have ensured that their domain configuration is safe). I think xen_emul_unplug=unnecessary better captures this. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
144 lines
4.4 KiB
C
144 lines
4.4 KiB
C
/******************************************************************************
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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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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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* Place - Suite 330, Boston, MA 02111-1307 USA.
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*
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*/
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <xen/platform_pci.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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int xen_platform_pci_unplug;
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EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
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#ifdef CONFIG_XEN_PVHVM
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static int xen_emul_unplug;
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static int __init 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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printk(KERN_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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printk(KERN_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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printk(KERN_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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printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
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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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void __init xen_unplug_emulated_devices(void)
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{
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int r;
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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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printk(KERN_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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printk(KERN_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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printk(KERN_WARNING "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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#endif
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