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
xen_efi_probe(void)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 */
xen_efi_get_secureboot(void)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
xen_efi_init(void)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
