From 637a5acb46b36a25b506ba6545e9a53350585b03 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Thu, 28 Nov 2013 00:52:52 +0100 Subject: [PATCH] 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 Reviewed-by: Markus Armbruster Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/pc_sysfw.c | 105 +++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 86 insertions(+), 19 deletions(-) diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c index e917c83540..75a7ebbaa7 100644 --- a/hw/i386/pc_sysfw.c +++ b/hw/i386/pc_sysfw.c @@ -72,35 +72,102 @@ static void pc_isa_bios_init(MemoryRegion *rom_memory, memory_region_set_readonly(isa_bios, true); } -static void pc_system_flash_init(MemoryRegion *rom_memory, - DriveInfo *pflash_drv) +#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; - hwaddr phys_addr; + char *fatal_errmsg = NULL; + hwaddr phys_addr = 0x100000000ULL; int sector_bits, sector_size; pflash_t *system_flash; MemoryRegion *flash_mem; + char name[64]; - bdrv = pflash_drv->bdrv; - size = bdrv_getlength(pflash_drv->bdrv); sector_bits = 12; sector_size = 1 << sector_bits; - if ((size % sector_size) != 0) { - fprintf(stderr, - "qemu: PC system firmware (pflash) must be a multiple of 0x%x\n", - sector_size); - exit(1); + 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); + } } - - phys_addr = 0x100000000ULL - size; - system_flash = pflash_cfi01_register(phys_addr, NULL, "system.flash", size, - bdrv, sector_size, size >> sector_bits, - 1, 0x0000, 0x0000, 0x0000, 0x0000, 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) @@ -181,5 +248,5 @@ void pc_system_firmware_init(MemoryRegion *rom_memory, bool isapc_ram_fw) exit(1); } - pc_system_flash_init(rom_memory, pflash_drv); + pc_system_flash_init(rom_memory); } -- 2.11.4.GIT