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-rw-r--r--arch/x86/xen/efi.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
new file mode 100644
index 000000000..7d7ffb9c8
--- /dev/null
+++ b/arch/x86/xen/efi.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Oracle Co., Daniel Kiper
+ */
+
+#include <linux/bitops.h>
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/string.h>
+
+#include <xen/xen.h>
+#include <xen/xen-ops.h>
+#include <xen/interface/platform.h>
+
+#include <asm/page.h>
+#include <asm/setup.h>
+#include <asm/xen/hypercall.h>
+
+static efi_char16_t vendor[100] __initdata;
+
+static efi_system_table_t efi_systab_xen __initdata = {
+ .hdr = {
+ .signature = EFI_SYSTEM_TABLE_SIGNATURE,
+ .revision = 0, /* Initialized later. */
+ .headersize = 0, /* Ignored by Linux Kernel. */
+ .crc32 = 0, /* Ignored by Linux Kernel. */
+ .reserved = 0
+ },
+ .fw_vendor = EFI_INVALID_TABLE_ADDR, /* Initialized later. */
+ .fw_revision = 0, /* Initialized later. */
+ .con_in_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
+ .con_in = NULL, /* Not used under Xen. */
+ .con_out_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
+ .con_out = NULL, /* Not used under Xen. */
+ .stderr_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
+ .stderr = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
+ .runtime = (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR,
+ /* Not used under Xen. */
+ .boottime = (efi_boot_services_t *)EFI_INVALID_TABLE_ADDR,
+ /* Not used under Xen. */
+ .nr_tables = 0, /* Initialized later. */
+ .tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */
+};
+
+static efi_system_table_t __init *xen_efi_probe(void)
+{
+ struct xen_platform_op op = {
+ .cmd = XENPF_firmware_info,
+ .u.firmware_info = {
+ .type = XEN_FW_EFI_INFO,
+ .index = XEN_FW_EFI_CONFIG_TABLE
+ }
+ };
+ union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
+
+ if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0)
+ return NULL;
+
+ /* Here we know that Xen runs on EFI platform. */
+ xen_efi_runtime_setup();
+
+ efi_systab_xen.tables = info->cfg.addr;
+ efi_systab_xen.nr_tables = info->cfg.nent;
+
+ op.cmd = XENPF_firmware_info;
+ op.u.firmware_info.type = XEN_FW_EFI_INFO;
+ op.u.firmware_info.index = XEN_FW_EFI_VENDOR;
+ info->vendor.bufsz = sizeof(vendor);
+ set_xen_guest_handle(info->vendor.name, vendor);
+
+ if (HYPERVISOR_platform_op(&op) == 0) {
+ efi_systab_xen.fw_vendor = __pa_symbol(vendor);
+ efi_systab_xen.fw_revision = info->vendor.revision;
+ } else
+ efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN");
+
+ op.cmd = XENPF_firmware_info;
+ op.u.firmware_info.type = XEN_FW_EFI_INFO;
+ op.u.firmware_info.index = XEN_FW_EFI_VERSION;
+
+ if (HYPERVISOR_platform_op(&op) == 0)
+ efi_systab_xen.hdr.revision = info->version;
+
+ op.cmd = XENPF_firmware_info;
+ op.u.firmware_info.type = XEN_FW_EFI_INFO;
+ op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION;
+
+ if (HYPERVISOR_platform_op(&op) == 0)
+ efi.runtime_version = info->version;
+
+ return &efi_systab_xen;
+}
+
+/*
+ * Determine whether we're in secure boot mode.
+ */
+static enum efi_secureboot_mode xen_efi_get_secureboot(void)
+{
+ static efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
+ enum efi_secureboot_mode mode;
+ efi_status_t status;
+ u8 moksbstate;
+ unsigned long size;
+
+ mode = efi_get_secureboot_mode(efi.get_variable);
+ if (mode == efi_secureboot_mode_unknown) {
+ pr_err("Could not determine UEFI Secure Boot status.\n");
+ return efi_secureboot_mode_unknown;
+ }
+ if (mode != efi_secureboot_mode_enabled)
+ return mode;
+
+ /* See if a user has put the shim into insecure mode. */
+ size = sizeof(moksbstate);
+ status = efi.get_variable(L"MokSBStateRT", &shim_guid,
+ NULL, &size, &moksbstate);
+
+ /* If it fails, we don't care why. Default to secure. */
+ if (status != EFI_SUCCESS)
+ goto secure_boot_enabled;
+
+ if (moksbstate == 1)
+ return efi_secureboot_mode_disabled;
+
+ secure_boot_enabled:
+ pr_info("UEFI Secure Boot is enabled.\n");
+ return efi_secureboot_mode_enabled;
+}
+
+void __init xen_efi_init(struct boot_params *boot_params)
+{
+ efi_system_table_t *efi_systab_xen;
+
+ efi_systab_xen = xen_efi_probe();
+
+ if (efi_systab_xen == NULL)
+ return;
+
+ strncpy((char *)&boot_params->efi_info.efi_loader_signature, "Xen",
+ sizeof(boot_params->efi_info.efi_loader_signature));
+ boot_params->efi_info.efi_systab = (__u32)__pa(efi_systab_xen);
+ boot_params->efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);
+
+ boot_params->secure_boot = xen_efi_get_secureboot();
+
+ set_bit(EFI_BOOT, &efi.flags);
+ set_bit(EFI_PARAVIRT, &efi.flags);
+ set_bit(EFI_64BIT, &efi.flags);
+}