1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2014 Oracle Co., Daniel Kiper 4 */ 5 6 #include <linux/bitops.h> 7 #include <linux/efi.h> 8 #include <linux/init.h> 9 #include <linux/string.h> 10 11 #include <xen/xen.h> 12 #include <xen/xen-ops.h> 13 #include <xen/interface/platform.h> 14 15 #include <asm/page.h> 16 #include <asm/setup.h> 17 #include <asm/xen/hypercall.h> 18 19 #include "xen-ops.h" 20 21 static efi_char16_t vendor[100] __initdata; 22 23 static efi_system_table_t efi_systab_xen __initdata = { 24 .hdr = { 25 .signature = EFI_SYSTEM_TABLE_SIGNATURE, 26 .revision = 0, /* Initialized later. */ 27 .headersize = 0, /* Ignored by Linux Kernel. */ 28 .crc32 = 0, /* Ignored by Linux Kernel. */ 29 .reserved = 0 30 }, 31 .fw_vendor = EFI_INVALID_TABLE_ADDR, /* Initialized later. */ 32 .fw_revision = 0, /* Initialized later. */ 33 .con_in_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 34 .con_in = NULL, /* Not used under Xen. */ 35 .con_out_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 36 .con_out = NULL, /* Not used under Xen. */ 37 .stderr_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 38 .stderr = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */ 39 .runtime = (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR, 40 /* Not used under Xen. */ 41 .boottime = (efi_boot_services_t *)EFI_INVALID_TABLE_ADDR, 42 /* Not used under Xen. */ 43 .nr_tables = 0, /* Initialized later. */ 44 .tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */ 45 }; 46 47 static efi_system_table_t __init *xen_efi_probe(void) 48 { 49 struct xen_platform_op op = { 50 .cmd = XENPF_firmware_info, 51 .u.firmware_info = { 52 .type = XEN_FW_EFI_INFO, 53 .index = XEN_FW_EFI_CONFIG_TABLE 54 } 55 }; 56 union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info; 57 58 if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0) 59 return NULL; 60 61 /* Here we know that Xen runs on EFI platform. */ 62 xen_efi_runtime_setup(); 63 64 efi_systab_xen.tables = info->cfg.addr; 65 efi_systab_xen.nr_tables = info->cfg.nent; 66 67 op.cmd = XENPF_firmware_info; 68 op.u.firmware_info.type = XEN_FW_EFI_INFO; 69 op.u.firmware_info.index = XEN_FW_EFI_VENDOR; 70 info->vendor.bufsz = sizeof(vendor); 71 set_xen_guest_handle(info->vendor.name, vendor); 72 73 if (HYPERVISOR_platform_op(&op) == 0) { 74 efi_systab_xen.fw_vendor = __pa_symbol(vendor); 75 efi_systab_xen.fw_revision = info->vendor.revision; 76 } else 77 efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN"); 78 79 op.cmd = XENPF_firmware_info; 80 op.u.firmware_info.type = XEN_FW_EFI_INFO; 81 op.u.firmware_info.index = XEN_FW_EFI_VERSION; 82 83 if (HYPERVISOR_platform_op(&op) == 0) 84 efi_systab_xen.hdr.revision = info->version; 85 86 op.cmd = XENPF_firmware_info; 87 op.u.firmware_info.type = XEN_FW_EFI_INFO; 88 op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION; 89 90 if (HYPERVISOR_platform_op(&op) == 0) 91 efi.runtime_version = info->version; 92 93 return &efi_systab_xen; 94 } 95 96 /* 97 * Determine whether we're in secure boot mode. 98 */ 99 static enum efi_secureboot_mode xen_efi_get_secureboot(void) 100 { 101 static efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID; 102 enum efi_secureboot_mode mode; 103 efi_status_t status; 104 u8 moksbstate; 105 unsigned long size; 106 107 mode = efi_get_secureboot_mode(efi.get_variable); 108 if (mode == efi_secureboot_mode_unknown) { 109 pr_err("Could not determine UEFI Secure Boot status.\n"); 110 return efi_secureboot_mode_unknown; 111 } 112 if (mode != efi_secureboot_mode_enabled) 113 return mode; 114 115 /* See if a user has put the shim into insecure mode. */ 116 size = sizeof(moksbstate); 117 status = efi.get_variable(L"MokSBStateRT", &shim_guid, 118 NULL, &size, &moksbstate); 119 120 /* If it fails, we don't care why. Default to secure. */ 121 if (status != EFI_SUCCESS) 122 goto secure_boot_enabled; 123 124 if (moksbstate == 1) 125 return efi_secureboot_mode_disabled; 126 127 secure_boot_enabled: 128 pr_info("UEFI Secure Boot is enabled.\n"); 129 return efi_secureboot_mode_enabled; 130 } 131 132 void __init xen_efi_init(struct boot_params *boot_params) 133 { 134 efi_system_table_t *efi_systab_xen; 135 136 efi_systab_xen = xen_efi_probe(); 137 138 if (efi_systab_xen == NULL) 139 return; 140 141 strncpy((char *)&boot_params->efi_info.efi_loader_signature, "Xen", 142 sizeof(boot_params->efi_info.efi_loader_signature)); 143 boot_params->efi_info.efi_systab = (__u32)__pa(efi_systab_xen); 144 boot_params->efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32); 145 146 boot_params->secure_boot = xen_efi_get_secureboot(); 147 148 set_bit(EFI_BOOT, &efi.flags); 149 set_bit(EFI_PARAVIRT, &efi.flags); 150 set_bit(EFI_64BIT, &efi.flags); 151 } 152