1 /* 2 * Copyright (c) 2014 Oracle Co., Daniel Kiper 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License along 15 * with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #include <linux/bitops.h> 19 #include <linux/efi.h> 20 #include <linux/init.h> 21 #include <linux/string.h> 22 23 #include <xen/xen.h> 24 #include <xen/xen-ops.h> 25 #include <xen/interface/platform.h> 26 27 #include <asm/page.h> 28 #include <asm/setup.h> 29 #include <asm/xen/hypercall.h> 30 31 static efi_char16_t vendor[100] __initdata; 32 33 static efi_system_table_t efi_systab_xen __initdata = { 34 .hdr = { 35 .signature = EFI_SYSTEM_TABLE_SIGNATURE, 36 .revision = 0, /* Initialized later. */ 37 .headersize = 0, /* Ignored by Linux Kernel. */ 38 .crc32 = 0, /* Ignored by Linux Kernel. */ 39 .reserved = 0 40 }, 41 .fw_vendor = EFI_INVALID_TABLE_ADDR, /* Initialized later. */ 42 .fw_revision = 0, /* Initialized later. */ 43 .con_in_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 44 .con_in = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 45 .con_out_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 46 .con_out = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 47 .stderr_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 48 .stderr = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 49 .runtime = (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR, 50 /* Not used under Xen. */ 51 .boottime = (efi_boot_services_t *)EFI_INVALID_TABLE_ADDR, 52 /* Not used under Xen. */ 53 .nr_tables = 0, /* Initialized later. */ 54 .tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */ 55 }; 56 57 static efi_system_table_t __init *xen_efi_probe(void) 58 { 59 struct xen_platform_op op = { 60 .cmd = XENPF_firmware_info, 61 .u.firmware_info = { 62 .type = XEN_FW_EFI_INFO, 63 .index = XEN_FW_EFI_CONFIG_TABLE 64 } 65 }; 66 union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info; 67 68 if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0) 69 return NULL; 70 71 /* Here we know that Xen runs on EFI platform. */ 72 73 efi.get_time = xen_efi_get_time; 74 efi.set_time = xen_efi_set_time; 75 efi.get_wakeup_time = xen_efi_get_wakeup_time; 76 efi.set_wakeup_time = xen_efi_set_wakeup_time; 77 efi.get_variable = xen_efi_get_variable; 78 efi.get_next_variable = xen_efi_get_next_variable; 79 efi.set_variable = xen_efi_set_variable; 80 efi.query_variable_info = xen_efi_query_variable_info; 81 efi.update_capsule = xen_efi_update_capsule; 82 efi.query_capsule_caps = xen_efi_query_capsule_caps; 83 efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count; 84 efi.reset_system = xen_efi_reset_system; 85 86 efi_systab_xen.tables = info->cfg.addr; 87 efi_systab_xen.nr_tables = info->cfg.nent; 88 89 op.cmd = XENPF_firmware_info; 90 op.u.firmware_info.type = XEN_FW_EFI_INFO; 91 op.u.firmware_info.index = XEN_FW_EFI_VENDOR; 92 info->vendor.bufsz = sizeof(vendor); 93 set_xen_guest_handle(info->vendor.name, vendor); 94 95 if (HYPERVISOR_platform_op(&op) == 0) { 96 efi_systab_xen.fw_vendor = __pa_symbol(vendor); 97 efi_systab_xen.fw_revision = info->vendor.revision; 98 } else 99 efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN"); 100 101 op.cmd = XENPF_firmware_info; 102 op.u.firmware_info.type = XEN_FW_EFI_INFO; 103 op.u.firmware_info.index = XEN_FW_EFI_VERSION; 104 105 if (HYPERVISOR_platform_op(&op) == 0) 106 efi_systab_xen.hdr.revision = info->version; 107 108 op.cmd = XENPF_firmware_info; 109 op.u.firmware_info.type = XEN_FW_EFI_INFO; 110 op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION; 111 112 if (HYPERVISOR_platform_op(&op) == 0) 113 efi.runtime_version = info->version; 114 115 return &efi_systab_xen; 116 } 117 118 /* 119 * Determine whether we're in secure boot mode. 120 * 121 * Please keep the logic in sync with 122 * drivers/firmware/efi/libstub/secureboot.c:efi_get_secureboot(). 123 */ 124 static enum efi_secureboot_mode xen_efi_get_secureboot(void) 125 { 126 static efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID; 127 static efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID; 128 efi_status_t status; 129 u8 moksbstate, secboot, setupmode; 130 unsigned long size; 131 132 size = sizeof(secboot); 133 status = efi.get_variable(L"SecureBoot", &efi_variable_guid, 134 NULL, &size, &secboot); 135 136 if (status == EFI_NOT_FOUND) 137 return efi_secureboot_mode_disabled; 138 139 if (status != EFI_SUCCESS) 140 goto out_efi_err; 141 142 size = sizeof(setupmode); 143 status = efi.get_variable(L"SetupMode", &efi_variable_guid, 144 NULL, &size, &setupmode); 145 146 if (status != EFI_SUCCESS) 147 goto out_efi_err; 148 149 if (secboot == 0 || setupmode == 1) 150 return efi_secureboot_mode_disabled; 151 152 /* See if a user has put the shim into insecure mode. */ 153 size = sizeof(moksbstate); 154 status = efi.get_variable(L"MokSBStateRT", &shim_guid, 155 NULL, &size, &moksbstate); 156 157 /* If it fails, we don't care why. Default to secure. */ 158 if (status != EFI_SUCCESS) 159 goto secure_boot_enabled; 160 161 if (moksbstate == 1) 162 return efi_secureboot_mode_disabled; 163 164 secure_boot_enabled: 165 pr_info("UEFI Secure Boot is enabled.\n"); 166 return efi_secureboot_mode_enabled; 167 168 out_efi_err: 169 pr_err("Could not determine UEFI Secure Boot status.\n"); 170 return efi_secureboot_mode_unknown; 171 } 172 173 void __init xen_efi_init(void) 174 { 175 efi_system_table_t *efi_systab_xen; 176 177 efi_systab_xen = xen_efi_probe(); 178 179 if (efi_systab_xen == NULL) 180 return; 181 182 strncpy((char *)&boot_params.efi_info.efi_loader_signature, "Xen", 183 sizeof(boot_params.efi_info.efi_loader_signature)); 184 boot_params.efi_info.efi_systab = (__u32)__pa(efi_systab_xen); 185 boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32); 186 187 boot_params.secure_boot = xen_efi_get_secureboot(); 188 189 set_bit(EFI_BOOT, &efi.flags); 190 set_bit(EFI_PARAVIRT, &efi.flags); 191 set_bit(EFI_64BIT, &efi.flags); 192 } 193