qemu-patch-raspberry4/hw/i386/pc_sysfw.c
Paolo Bonzini b2f73a0784 sev/i386: Allow AP booting under SEV-ES
When SEV-ES is enabled, it is not possible modify the guests register
state after it has been initially created, encrypted and measured.

Normally, an INIT-SIPI-SIPI request is used to boot the AP. However, the
hypervisor cannot emulate this because it cannot update the AP register
state. For the very first boot by an AP, the reset vector CS segment
value and the EIP value must be programmed before the register has been
encrypted and measured. Search the guest firmware for the guest for a
specific GUID that tells Qemu the value of the reset vector to use.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <22db2bfb4d6551aed661a9ae95b4fdbef613ca21.1611682609.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-16 17:15:39 +01:00

371 lines
12 KiB
C

/*
* QEMU PC System Firmware
*
* Copyright (c) 2003-2004 Fabrice Bellard
* Copyright (c) 2011-2012 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qapi/error.h"
#include "sysemu/block-backend.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "qemu/units.h"
#include "hw/sysbus.h"
#include "hw/i386/x86.h"
#include "hw/i386/pc.h"
#include "hw/loader.h"
#include "hw/qdev-properties.h"
#include "sysemu/sysemu.h"
#include "hw/block/flash.h"
#include "sysemu/kvm.h"
#include "sysemu/sev.h"
#define FLASH_SECTOR_SIZE 4096
static void pc_isa_bios_init(MemoryRegion *rom_memory,
MemoryRegion *flash_mem,
int ram_size)
{
int isa_bios_size;
MemoryRegion *isa_bios;
uint64_t flash_size;
void *flash_ptr, *isa_bios_ptr;
flash_size = memory_region_size(flash_mem);
/* map the last 128KB of the BIOS in ISA space */
isa_bios_size = MIN(flash_size, 128 * KiB);
isa_bios = g_malloc(sizeof(*isa_bios));
memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size,
&error_fatal);
memory_region_add_subregion_overlap(rom_memory,
0x100000 - isa_bios_size,
isa_bios,
1);
/* copy ISA rom image from top of flash memory */
flash_ptr = memory_region_get_ram_ptr(flash_mem);
isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
memcpy(isa_bios_ptr,
((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
isa_bios_size);
memory_region_set_readonly(isa_bios, true);
}
static PFlashCFI01 *pc_pflash_create(PCMachineState *pcms,
const char *name,
const char *alias_prop_name)
{
DeviceState *dev = qdev_new(TYPE_PFLASH_CFI01);
qdev_prop_set_uint64(dev, "sector-length", FLASH_SECTOR_SIZE);
qdev_prop_set_uint8(dev, "width", 1);
qdev_prop_set_string(dev, "name", name);
object_property_add_child(OBJECT(pcms), name, OBJECT(dev));
object_property_add_alias(OBJECT(pcms), alias_prop_name,
OBJECT(dev), "drive");
/*
* The returned reference is tied to the child property and
* will be removed with object_unparent.
*/
object_unref(OBJECT(dev));
return PFLASH_CFI01(dev);
}
void pc_system_flash_create(PCMachineState *pcms)
{
PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
if (pcmc->pci_enabled) {
pcms->flash[0] = pc_pflash_create(pcms, "system.flash0",
"pflash0");
pcms->flash[1] = pc_pflash_create(pcms, "system.flash1",
"pflash1");
}
}
void pc_system_flash_cleanup_unused(PCMachineState *pcms)
{
char *prop_name;
int i;
Object *dev_obj;
assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
dev_obj = OBJECT(pcms->flash[i]);
if (!object_property_get_bool(dev_obj, "realized", &error_abort)) {
prop_name = g_strdup_printf("pflash%d", i);
object_property_del(OBJECT(pcms), prop_name);
g_free(prop_name);
object_unparent(dev_obj);
pcms->flash[i] = NULL;
}
}
}
#define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d"
static uint8_t *ovmf_table;
static int ovmf_table_len;
static void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
{
uint8_t *ptr;
QemuUUID guid;
int tot_len;
/* should only be called once */
if (ovmf_table) {
return;
}
if (flash_size < TARGET_PAGE_SIZE) {
return;
}
/*
* if this is OVMF there will be a table footer
* guid 48 bytes before the end of the flash file. If it's
* not found, silently abort the flash parsing.
*/
qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid);
guid = qemu_uuid_bswap(guid); /* guids are LE */
ptr = flash_ptr + flash_size - 48;
if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) {
return;
}
/* if found, just before is two byte table length */
ptr -= sizeof(uint16_t);
tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t);
if (tot_len <= 0) {
return;
}
ovmf_table = g_malloc(tot_len);
ovmf_table_len = tot_len;
/*
* ptr is the foot of the table, so copy it all to the newly
* allocated ovmf_table and then set the ovmf_table pointer
* to the table foot
*/
memcpy(ovmf_table, ptr - tot_len, tot_len);
ovmf_table += tot_len;
}
bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
int *data_len)
{
uint8_t *ptr = ovmf_table;
int tot_len = ovmf_table_len;
QemuUUID entry_guid;
if (qemu_uuid_parse(entry, &entry_guid) < 0) {
return false;
}
if (!ptr) {
return false;
}
entry_guid = qemu_uuid_bswap(entry_guid); /* guids are LE */
while (tot_len >= sizeof(QemuUUID) + sizeof(uint16_t)) {
int len;
QemuUUID *guid;
/*
* The data structure is
* arbitrary length data
* 2 byte length of entire entry
* 16 byte guid
*/
guid = (QemuUUID *)(ptr - sizeof(QemuUUID));
len = le16_to_cpu(*(uint16_t *)(ptr - sizeof(QemuUUID) -
sizeof(uint16_t)));
/*
* just in case the table is corrupt, wouldn't want to spin in
* the zero case
*/
if (len < sizeof(QemuUUID) + sizeof(uint16_t)) {
return false;
} else if (len > tot_len) {
return false;
}
ptr -= len;
tot_len -= len;
if (qemu_uuid_is_equal(guid, &entry_guid)) {
if (data) {
*data = ptr;
}
if (data_len) {
*data_len = len - sizeof(QemuUUID) - sizeof(uint16_t);
}
return true;
}
}
return false;
}
/*
* Map the pcms->flash[] from 4GiB downward, and realize.
* Map them in descending order, i.e. pcms->flash[0] at the top,
* without gaps.
* Stop at the first pcms->flash[0] lacking a block backend.
* Set each flash's size from its block backend. Fatal error if the
* size isn't a non-zero multiple of 4KiB, or the total size exceeds
* pcms->max_fw_size.
*
* If pcms->flash[0] has a block backend, its memory is passed to
* pc_isa_bios_init(). Merging several flash devices for isa-bios is
* not supported.
*/
static void pc_system_flash_map(PCMachineState *pcms,
MemoryRegion *rom_memory)
{
hwaddr total_size = 0;
int i;
BlockBackend *blk;
int64_t size;
PFlashCFI01 *system_flash;
MemoryRegion *flash_mem;
void *flash_ptr;
int flash_size;
int ret;
assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
system_flash = pcms->flash[i];
blk = pflash_cfi01_get_blk(system_flash);
if (!blk) {
break;
}
size = blk_getlength(blk);
if (size < 0) {
error_report("can't get size of block device %s: %s",
blk_name(blk), strerror(-size));
exit(1);
}
if (size == 0 || !QEMU_IS_ALIGNED(size, FLASH_SECTOR_SIZE)) {
error_report("system firmware block device %s has invalid size "
"%" PRId64,
blk_name(blk), size);
info_report("its size must be a non-zero multiple of 0x%x",
FLASH_SECTOR_SIZE);
exit(1);
}
if ((hwaddr)size != size
|| total_size > HWADDR_MAX - size
|| total_size + size > pcms->max_fw_size) {
error_report("combined size of system firmware exceeds "
"%" PRIu64 " bytes",
pcms->max_fw_size);
exit(1);
}
total_size += size;
qdev_prop_set_uint32(DEVICE(system_flash), "num-blocks",
size / FLASH_SECTOR_SIZE);
sysbus_realize_and_unref(SYS_BUS_DEVICE(system_flash), &error_fatal);
sysbus_mmio_map(SYS_BUS_DEVICE(system_flash), 0,
0x100000000ULL - total_size);
if (i == 0) {
flash_mem = pflash_cfi01_get_memory(system_flash);
pc_isa_bios_init(rom_memory, flash_mem, size);
/* Encrypt the pflash boot ROM */
if (sev_enabled()) {
flash_ptr = memory_region_get_ram_ptr(flash_mem);
flash_size = memory_region_size(flash_mem);
/*
* OVMF places a GUIDed structures in the flash, so
* search for them
*/
pc_system_parse_ovmf_flash(flash_ptr, flash_size);
ret = sev_es_save_reset_vector(flash_ptr, flash_size);
if (ret) {
error_report("failed to locate and/or save reset vector");
exit(1);
}
sev_encrypt_flash(flash_ptr, flash_size, &error_fatal);
}
}
}
}
void pc_system_firmware_init(PCMachineState *pcms,
MemoryRegion *rom_memory)
{
PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
int i;
BlockBackend *pflash_blk[ARRAY_SIZE(pcms->flash)];
if (!pcmc->pci_enabled) {
x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, true);
return;
}
/* Map legacy -drive if=pflash to machine properties */
for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
pflash_cfi01_legacy_drive(pcms->flash[i],
drive_get(IF_PFLASH, 0, i));
pflash_blk[i] = pflash_cfi01_get_blk(pcms->flash[i]);
}
/* Reject gaps */
for (i = 1; i < ARRAY_SIZE(pcms->flash); i++) {
if (pflash_blk[i] && !pflash_blk[i - 1]) {
error_report("pflash%d requires pflash%d", i, i - 1);
exit(1);
}
}
if (!pflash_blk[0]) {
/* Machine property pflash0 not set, use ROM mode */
x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
} else {
if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
/*
* Older KVM cannot execute from device memory. So, flash
* memory cannot be used unless the readonly memory kvm
* capability is present.
*/
error_report("pflash with kvm requires KVM readonly memory support");
exit(1);
}
pc_system_flash_map(pcms, rom_memory);
}
pc_system_flash_cleanup_unused(pcms);
}