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authorLaszlo Ersek <lersek@redhat.com>2013-11-28 00:52:52 +0100
committerMichael S. Tsirkin <mst@redhat.com>2013-12-23 13:12:34 +0200
commit637a5acb46b36a25b506ba6545e9a53350585b03 (patch)
treefa4e916e5af64d36063b0744cd7c93f2b9a9b14c /hw/i386/pc_sysfw.c
parentecdbfceb0f20a3ef784bf522ed7264660aa3d150 (diff)
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>
Diffstat (limited to 'hw/i386/pc_sysfw.c')
-rw-r--r--hw/i386/pc_sysfw.c105
1 files 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);
}