diff options
Diffstat (limited to 'hw/block/pc_sysfw.c')
| -rw-r--r-- | hw/block/pc_sysfw.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/hw/block/pc_sysfw.c b/hw/block/pc_sysfw.c index 0d95c8a926..aad8614465 100644 --- a/hw/block/pc_sysfw.c +++ b/hw/block/pc_sysfw.c @@ -194,11 +194,23 @@ static void old_pc_system_rom_init(MemoryRegion *rom_memory) bios); } +/* + * Bug-compatible flash vs. ROM selection enabled? + * A few older machines enable this. + */ +bool pc_sysfw_flash_vs_rom_bug_compatible; + void pc_system_firmware_init(MemoryRegion *rom_memory) { DriveInfo *pflash_drv; PcSysFwDevice *sysfw_dev; + /* + * TODO This device exists only so that users can switch between + * use of flash and ROM for the BIOS. The ability to switch was + * created because flash doesn't work with KVM. Once it does, we + * should drop this device for new machine types. + */ sysfw_dev = (PcSysFwDevice*) qdev_create(NULL, "pc-sysfw"); qdev_init_nofail(DEVICE(sysfw_dev)); @@ -212,7 +224,11 @@ void pc_system_firmware_init(MemoryRegion *rom_memory) /* Currently KVM cannot execute from device memory. Use old rom based firmware initialization for KVM. */ - if (kvm_enabled()) { + /* + * This is a Bad Idea, because it makes enabling/disabling KVM + * guest-visible. Do it only in bug-compatibility mode. + */ + if (pc_sysfw_flash_vs_rom_bug_compatible && kvm_enabled()) { if (pflash_drv != NULL) { fprintf(stderr, "qemu: pflash cannot be used with kvm enabled\n"); exit(1); @@ -239,7 +255,7 @@ void pc_system_firmware_init(MemoryRegion *rom_memory) } static Property pcsysfw_properties[] = { - DEFINE_PROP_UINT8("rom_only", PcSysFwDevice, rom_only, 0), + DEFINE_PROP_UINT8("rom_only", PcSysFwDevice, rom_only, 1), DEFINE_PROP_END_OF_LIST(), }; |