qemu-e2k/hw/i386/pc_sysfw.c
Laszlo Ersek 637a5acb46 hw/i386/pc_sysfw: support two flash drives
This patch allows the user to usefully specify

  -drive file=img_1,if=pflash,format=raw,readonly \
  -drive file=img_2,if=pflash,format=raw

on the command line. The flash images will be mapped under 4G in their
reverse unit order -- that is, with their base addresses progressing
downwards, in increasing unit order.

(The unit number increases with command line order if not explicitly
specified.)

This accommodates the following use case: suppose that OVMF is split in
two parts, a writeable host file for non-volatile variable storage, and a
read-only part for bootstrap and decompressible executable code.

The binary code part would be read-only, centrally managed on the host
system, and passed in as unit 0. The variable store would be writeable,
VM-specific, and passed in as unit 1.

  00000000ffe00000-00000000ffe1ffff (prio 0, R-): system.flash1
  00000000ffe20000-00000000ffffffff (prio 0, R-): system.flash0

(If the guest tries to write to the flash range that is backed by the
read-only drive, pflash_update() is never called; various flash
programming/erase errors are returned to the guest instead. See the
callers of pflash_update(), and the initialization of "pfl->ro", in
"hw/block/pflash_cfi01.c".)

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-12-23 13:12:34 +02:00

253 lines
9.1 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 "sysemu/blockdev.h"
#include "qemu/error-report.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"
typedef struct PcSysFwDevice {
SysBusDevice busdev;
uint8_t isapc_ram_fw;
} PcSysFwDevice;
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 * 1024);
isa_bios = g_malloc(sizeof(*isa_bios));
memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size);
vmstate_register_ram_global(isa_bios);
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);
}
#define FLASH_MAP_UNIT_MAX 2
/* 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_MAP_BASE_MIN ((hwaddr)(0x100000000ULL - 8*1024*1024))
/* This function maps flash drives from 4G downward, in order of their unit
* numbers. The mapping starts at unit#0, with unit number increments of 1, and
* stops before the first missing flash drive, or before
* unit#FLASH_MAP_UNIT_MAX, whichever is reached first.
*
* Addressing within one flash drive is of course not reversed.
*
* An error message is printed and the process exits if:
* - the size of the backing file for a flash drive is non-positive, or not a
* multiple of the required sector size, or
* - the current mapping's base address would fall below FLASH_MAP_BASE_MIN.
*
* The drive with unit#0 (if available) is mapped at the highest address, and
* it is passed to pc_isa_bios_init(). Merging several drives for isa-bios is
* not supported.
*/
static void pc_system_flash_init(MemoryRegion *rom_memory)
{
int unit;
DriveInfo *pflash_drv;
BlockDriverState *bdrv;
int64_t size;
char *fatal_errmsg = NULL;
hwaddr phys_addr = 0x100000000ULL;
int sector_bits, sector_size;
pflash_t *system_flash;
MemoryRegion *flash_mem;
char name[64];
sector_bits = 12;
sector_size = 1 << sector_bits;
for (unit = 0;
(unit < FLASH_MAP_UNIT_MAX &&
(pflash_drv = drive_get(IF_PFLASH, 0, unit)) != NULL);
++unit) {
bdrv = pflash_drv->bdrv;
size = bdrv_getlength(bdrv);
if (size < 0) {
fatal_errmsg = g_strdup_printf("failed to get backing file size");
} else if (size == 0) {
fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
"cannot have zero size");
} else if ((size % sector_size) != 0) {
fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
"must be a multiple of 0x%x", sector_size);
} else if (phys_addr < size || phys_addr - size < FLASH_MAP_BASE_MIN) {
fatal_errmsg = g_strdup_printf("oversized backing file, pflash "
"segments cannot be mapped under "
TARGET_FMT_plx, FLASH_MAP_BASE_MIN);
}
if (fatal_errmsg != NULL) {
Location loc;
/* push a new, "none" location on the location stack; overwrite its
* contents with the location saved in the option; print the error
* (includes location); pop the top
*/
loc_push_none(&loc);
if (pflash_drv->opts != NULL) {
qemu_opts_loc_restore(pflash_drv->opts);
}
error_report("%s", fatal_errmsg);
loc_pop(&loc);
g_free(fatal_errmsg);
exit(1);
}
phys_addr -= size;
/* pflash_cfi01_register() creates a deep copy of the name */
snprintf(name, sizeof name, "system.flash%d", unit);
system_flash = pflash_cfi01_register(phys_addr, NULL /* qdev */, name,
size, bdrv, sector_size,
size >> sector_bits,
1 /* width */,
0x0000 /* id0 */,
0x0000 /* id1 */,
0x0000 /* id2 */,
0x0000 /* id3 */,
0 /* be */);
if (unit == 0) {
flash_mem = pflash_cfi01_get_memory(system_flash);
pc_isa_bios_init(rom_memory, flash_mem, size);
}
}
}
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);
vmstate_register_ram_global(bios);
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);
}
if (filename) {
g_free(filename);
}
/* map the last 128KB of the BIOS in ISA space */
isa_bios_size = bios_size;
if (isa_bios_size > (128 * 1024)) {
isa_bios_size = 128 * 1024;
}
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(MemoryRegion *rom_memory, bool isapc_ram_fw)
{
DriveInfo *pflash_drv;
pflash_drv = drive_get(IF_PFLASH, 0, 0);
if (isapc_ram_fw || pflash_drv == NULL) {
/* When a pflash drive is not found, use rom-mode */
old_pc_system_rom_init(rom_memory, isapc_ram_fw);
return;
}
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. */
fprintf(stderr, "qemu: pflash with kvm requires KVM readonly memory support\n");
exit(1);
}
pc_system_flash_init(rom_memory);
}