qemu-e2k/hw/i386/pc_sysfw.c
Markus Armbruster ebc29e1bea pc: Support firmware configuration with -blockdev
The PC machines put firmware in ROM by default.  To get it put into
flash memory (required by OVMF), you have to use -drive
if=pflash,unit=0,... and optionally -drive if=pflash,unit=1,...

Why two -drive?  This permits setting up one part of the flash memory
read-only, and the other part read/write.  It also makes upgrading
firmware on the host easier.  Below the hood, it creates two separate
flash devices, because we were too lazy to improve our flash device
models to support sector protection.

The problem at hand is to do the same with -blockdev somehow, as one
more step towards deprecating -drive.

Mapping -drive if=none,... to -blockdev is a solved problem.  With
if=T other than if=none, -drive additionally configures a block device
frontend.  For non-onboard devices, that part maps to -device.  Also a
solved problem.  For onboard devices such as PC flash memory, we have
an unsolved problem.

This is actually an instance of a wider problem: our general device
configuration interface doesn't cover onboard devices.  Instead, we have
a zoo of ad hoc interfaces that are much more limited.  One of them is
-drive, which we'd rather deprecate, but can't until we have suitable
replacements for all its uses.

Sadly, I can't attack the wider problem today.  So back to the narrow
problem.

My first idea was to reduce it to its solved buddy by using pluggable
instead of onboard devices for the flash memory.  Workable, but it
requires some extra smarts in firmware descriptors and libvirt.  Paolo
had an idea that is simpler for libvirt: keep the devices onboard, and
add machine properties for their block backends.

The implementation is less than straightforward, I'm afraid.

First, block backend properties are *qdev* properties.  Machines can't
have those, as they're not devices.  I could duplicate these qdev
properties as QOM properties, but I hate that.

More seriously, the properties do not belong to the machine, they
belong to the onboard flash devices.  Adding them to the machine would
then require bad magic to somehow transfer them to the flash devices.
Fortunately, QOM provides the means to handle exactly this case: add
alias properties to the machine that forward to the onboard devices'
properties.

Properties need to be created in .instance_init() methods.  For PC
machines, that's pc_machine_initfn().  To make alias properties work,
we need to create the onboard flash devices there, too.  Requires
several bug fixes, in the previous commits.  We also have to realize
the devices.  More on that below.

If the user sets pflash0, firmware resides in flash memory.
pc_system_firmware_init() maps and realizes the flash devices.

Else, firmware resides in ROM.  The onboard flash devices aren't used
then.  pc_system_firmware_init() destroys them unrealized, along with
the alias properties.

The existing code to pick up drives defined with -drive if=pflash is
replaced by code to desugar into the machine properties.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <87ftrtux81.fsf@dusky.pond.sub.org>
2019-03-11 22:54:26 +01:00

327 lines
11 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 "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/hw.h"
#include "hw/i386/pc.h"
#include "hw/boards.h"
#include "hw/loader.h"
#include "sysemu/sysemu.h"
#include "hw/block/flash.h"
#include "sysemu/kvm.h"
#define BIOS_FILENAME "bios.bin"
/*
* We don't have a theoretically justifiable exact lower bound on the base
* address of any flash mapping. In practice, the IO-APIC MMIO range is
* [0xFEE00000..0xFEE01000] -- see IO_APIC_DEFAULT_ADDRESS --, leaving free
* only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB in
* size.
*/
#define FLASH_SIZE_LIMIT (8 * MiB)
#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_create(NULL, 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),
&error_abort);
object_property_add_alias(OBJECT(pcms), alias_prop_name,
OBJECT(dev), "drive", &error_abort);
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");
}
}
static 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, &error_abort);
g_free(prop_name);
object_unparent(dev_obj);
pcms->flash[i] = NULL;
}
}
}
/*
* 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
* FLASH_SIZE_LIMIT.
*
* 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 ret, flash_size;
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 || size % FLASH_SECTOR_SIZE != 0) {
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 > FLASH_SIZE_LIMIT) {
error_report("combined size of system firmware exceeds "
"%" PRIu64 " bytes",
FLASH_SIZE_LIMIT);
exit(1);
}
total_size += size;
qdev_prop_set_uint32(DEVICE(system_flash), "num-blocks",
size / FLASH_SECTOR_SIZE);
qdev_init_nofail(DEVICE(system_flash));
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 (kvm_memcrypt_enabled()) {
flash_ptr = memory_region_get_ram_ptr(flash_mem);
flash_size = memory_region_size(flash_mem);
ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size);
if (ret) {
error_report("failed to encrypt pflash rom");
exit(1);
}
}
}
}
}
static void old_pc_system_rom_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
{
char *filename;
MemoryRegion *bios, *isa_bios;
int bios_size, isa_bios_size;
int ret;
/* BIOS load */
if (bios_name == NULL) {
bios_name = BIOS_FILENAME;
}
filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
if (filename) {
bios_size = get_image_size(filename);
} else {
bios_size = -1;
}
if (bios_size <= 0 ||
(bios_size % 65536) != 0) {
goto bios_error;
}
bios = g_malloc(sizeof(*bios));
memory_region_init_ram(bios, NULL, "pc.bios", bios_size, &error_fatal);
if (!isapc_ram_fw) {
memory_region_set_readonly(bios, true);
}
ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
if (ret != 0) {
bios_error:
fprintf(stderr, "qemu: could not load PC BIOS '%s'\n", bios_name);
exit(1);
}
g_free(filename);
/* map the last 128KB of the BIOS in ISA space */
isa_bios_size = MIN(bios_size, 128 * KiB);
isa_bios = g_malloc(sizeof(*isa_bios));
memory_region_init_alias(isa_bios, NULL, "isa-bios", bios,
bios_size - isa_bios_size, isa_bios_size);
memory_region_add_subregion_overlap(rom_memory,
0x100000 - isa_bios_size,
isa_bios,
1);
if (!isapc_ram_fw) {
memory_region_set_readonly(isa_bios, true);
}
/* map all the bios at the top of memory */
memory_region_add_subregion(rom_memory,
(uint32_t)(-bios_size),
bios);
}
void pc_system_firmware_init(PCMachineState *pcms,
MemoryRegion *rom_memory)
{
PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
int i;
DriveInfo *pflash_drv;
BlockBackend *pflash_blk[ARRAY_SIZE(pcms->flash)];
Location loc;
if (!pcmc->pci_enabled) {
old_pc_system_rom_init(rom_memory, true);
return;
}
/* Map legacy -drive if=pflash to machine properties */
for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
pflash_blk[i] = pflash_cfi01_get_blk(pcms->flash[i]);
pflash_drv = drive_get(IF_PFLASH, 0, i);
if (!pflash_drv) {
continue;
}
loc_push_none(&loc);
qemu_opts_loc_restore(pflash_drv->opts);
if (pflash_blk[i]) {
error_report("clashes with -machine");
exit(1);
}
pflash_blk[i] = blk_by_legacy_dinfo(pflash_drv);
qdev_prop_set_drive(DEVICE(pcms->flash[i]),
"drive", pflash_blk[i], &error_fatal);
loc_pop(&loc);
}
/* 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 */
old_pc_system_rom_init(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);
}