1 /****************************************************************************** 2 * platform-pci-unplug.c 3 * 4 * Xen platform PCI device driver 5 * Copyright (c) 2010, Citrix 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 18 * Place - Suite 330, Boston, MA 02111-1307 USA. 19 * 20 */ 21 22 #include <linux/init.h> 23 #include <linux/io.h> 24 #include <linux/module.h> 25 26 #include <xen/platform_pci.h> 27 #include "xen-ops.h" 28 29 #define XEN_PLATFORM_ERR_MAGIC -1 30 #define XEN_PLATFORM_ERR_PROTOCOL -2 31 #define XEN_PLATFORM_ERR_BLACKLIST -3 32 33 #ifdef CONFIG_XEN_PVHVM 34 /* store the value of xen_emul_unplug after the unplug is done */ 35 static int xen_platform_pci_unplug; 36 static int xen_emul_unplug; 37 38 static int check_platform_magic(void) 39 { 40 short magic; 41 char protocol; 42 43 magic = inw(XEN_IOPORT_MAGIC); 44 if (magic != XEN_IOPORT_MAGIC_VAL) { 45 printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n"); 46 return XEN_PLATFORM_ERR_MAGIC; 47 } 48 49 protocol = inb(XEN_IOPORT_PROTOVER); 50 51 printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n", 52 protocol); 53 54 switch (protocol) { 55 case 1: 56 outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM); 57 outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER); 58 if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) { 59 printk(KERN_ERR "Xen Platform: blacklisted by host\n"); 60 return XEN_PLATFORM_ERR_BLACKLIST; 61 } 62 break; 63 default: 64 printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version"); 65 return XEN_PLATFORM_ERR_PROTOCOL; 66 } 67 68 return 0; 69 } 70 71 bool xen_has_pv_devices() 72 { 73 if (!xen_domain()) 74 return false; 75 76 /* PV domains always have them. */ 77 if (xen_pv_domain()) 78 return true; 79 80 /* And user has xen_platform_pci=0 set in guest config as 81 * driver did not modify the value. */ 82 if (xen_platform_pci_unplug == 0) 83 return false; 84 85 if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER) 86 return false; 87 88 if (xen_platform_pci_unplug & XEN_UNPLUG_ALL) 89 return true; 90 91 /* This is an odd one - we are going to run legacy 92 * and PV drivers at the same time. */ 93 if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) 94 return true; 95 96 /* And the caller has to follow with xen_pv_{disk,nic}_devices 97 * to be certain which driver can load. */ 98 return false; 99 } 100 EXPORT_SYMBOL_GPL(xen_has_pv_devices); 101 102 static bool __xen_has_pv_device(int state) 103 { 104 /* HVM domains might or might not */ 105 if (xen_hvm_domain() && (xen_platform_pci_unplug & state)) 106 return true; 107 108 return xen_has_pv_devices(); 109 } 110 111 bool xen_has_pv_nic_devices(void) 112 { 113 return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL); 114 } 115 EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices); 116 117 bool xen_has_pv_disk_devices(void) 118 { 119 return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS | 120 XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL); 121 } 122 EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices); 123 124 /* 125 * This one is odd - it determines whether you want to run PV _and_ 126 * legacy (IDE) drivers together. This combination is only possible 127 * under HVM. 128 */ 129 bool xen_has_pv_and_legacy_disk_devices(void) 130 { 131 if (!xen_domain()) 132 return false; 133 134 /* N.B. This is only ever used in HVM mode */ 135 if (xen_pv_domain()) 136 return false; 137 138 if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) 139 return true; 140 141 return false; 142 } 143 EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices); 144 145 void xen_unplug_emulated_devices(void) 146 { 147 int r; 148 149 /* user explicitly requested no unplug */ 150 if (xen_emul_unplug & XEN_UNPLUG_NEVER) 151 return; 152 /* check the version of the xen platform PCI device */ 153 r = check_platform_magic(); 154 /* If the version matches enable the Xen platform PCI driver. 155 * Also enable the Xen platform PCI driver if the host does 156 * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC) 157 * but the user told us that unplugging is unnecessary. */ 158 if (r && !(r == XEN_PLATFORM_ERR_MAGIC && 159 (xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))) 160 return; 161 /* Set the default value of xen_emul_unplug depending on whether or 162 * not the Xen PV frontends and the Xen platform PCI driver have 163 * been compiled for this kernel (modules or built-in are both OK). */ 164 if (!xen_emul_unplug) { 165 if (xen_must_unplug_nics()) { 166 printk(KERN_INFO "Netfront and the Xen platform PCI driver have " 167 "been compiled for this kernel: unplug emulated NICs.\n"); 168 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; 169 } 170 if (xen_must_unplug_disks()) { 171 printk(KERN_INFO "Blkfront and the Xen platform PCI driver have " 172 "been compiled for this kernel: unplug emulated disks.\n" 173 "You might have to change the root device\n" 174 "from /dev/hd[a-d] to /dev/xvd[a-d]\n" 175 "in your root= kernel command line option\n"); 176 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; 177 } 178 } 179 /* Now unplug the emulated devices */ 180 if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)) 181 outw(xen_emul_unplug, XEN_IOPORT_UNPLUG); 182 xen_platform_pci_unplug = xen_emul_unplug; 183 } 184 185 static int __init parse_xen_emul_unplug(char *arg) 186 { 187 char *p, *q; 188 int l; 189 190 for (p = arg; p; p = q) { 191 q = strchr(p, ','); 192 if (q) { 193 l = q - p; 194 q++; 195 } else { 196 l = strlen(p); 197 } 198 if (!strncmp(p, "all", l)) 199 xen_emul_unplug |= XEN_UNPLUG_ALL; 200 else if (!strncmp(p, "ide-disks", l)) 201 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; 202 else if (!strncmp(p, "aux-ide-disks", l)) 203 xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS; 204 else if (!strncmp(p, "nics", l)) 205 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; 206 else if (!strncmp(p, "unnecessary", l)) 207 xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY; 208 else if (!strncmp(p, "never", l)) 209 xen_emul_unplug |= XEN_UNPLUG_NEVER; 210 else 211 printk(KERN_WARNING "unrecognised option '%s' " 212 "in parameter 'xen_emul_unplug'\n", p); 213 } 214 return 0; 215 } 216 early_param("xen_emul_unplug", parse_xen_emul_unplug); 217 #endif 218