On Mon, Apr 24, 2017 at 08:58:17PM +0200, Igor Mammedov wrote: [...] > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > index f3b372a18f..3f2d96da64 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -1047,7 +1047,7 @@ static void load_linux(PCMachineState *pcms, > fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size); > fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size); > > - if (fw_cfg_dma_enabled(fw_cfg)) { > + if (!pcmc->linuxboot_dma_disabled && fw_cfg_dma_enabled(fw_cfg)) {
Why not name the flag just "linuxboot_dma", set it to true by default at pc_machine_class_init(), and avoid the double negative? [...] > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > index f278b3ae89..ff6f13b61b 100644 > --- a/include/hw/i386/pc.h > +++ b/include/hw/i386/pc.h > @@ -151,6 +151,8 @@ struct PCMachineClass { > bool save_tsc_khz; > /* generate legacy CPU hotplug AML */ > bool legacy_cpu_hotplug; > + A one-line description of the consequences of setting/clearing the flag would be nice. > + bool linuxboot_dma_disabled; > }; > > #define TYPE_PC_MACHINE "generic-pc-machine" > @@ -432,10 +434,6 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t > *); > #define PC_COMPAT_2_6 \ > HW_COMPAT_2_6 \ > {\ > - .driver = "fw_cfg_io",\ > - .property = "dma_enabled",\ > - .value = "off",\ > - },{\ > .driver = TYPE_X86_CPU,\ > .property = "cpuid-0xb",\ > .value = "off",\ > -- > 2.11.0 (Apple Git-81) > -- Eduardo