https://github.com/torvalds/linux
Tip revision: b401b621758e46812da61fa58a67c3fd8d91de0d authored by Linus Torvalds on 18 February 2024, 20:56:25 UTC
Linux 6.8-rc5
Linux 6.8-rc5
Tip revision: b401b62
efi.c
// 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>
#include "xen-ops.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;
strscpy((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);
}