Re: [PATCH v4 07/27] hw/i386/x86: Remove X86MachineClass::fwcfg_dma_enabled field

[Igor Mammedov <imammedo@redhat.com>]

On Thu,  8 May 2025 15:35:30 +0200
Philippe Mathieu-Daudé <philmd@linaro.org> wrote:

> The X86MachineClass::fwcfg_dma_enabled boolean was only used
> by the pc-q35-2.6 and pc-i440fx-2.6 machines, which got
> removed. Remove it and simplify.
> 
> 'multiboot.bin' isn't used anymore, we'll remove it in the
> next commit.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  include/hw/i386/x86.h | 2 --
>  hw/i386/microvm.c     | 3 ---
>  hw/i386/multiboot.c   | 7 +------
>  hw/i386/x86-common.c  | 3 +--
>  hw/i386/x86.c         | 2 --
>  5 files changed, 2 insertions(+), 15 deletions(-)
> 
> diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
> index fc460b82f82..29d37af11e6 100644
> --- a/include/hw/i386/x86.h
> +++ b/include/hw/i386/x86.h
> @@ -29,8 +29,6 @@
>  struct X86MachineClass {
>      MachineClass parent;
>  
> -    /* use DMA capable linuxboot option rom */
> -    bool fwcfg_dma_enabled;
>      /* CPU and apic information: */
>      bool apic_xrupt_override;
>  };
> diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
> index e0daf0d4fc3..b1262fb1523 100644
> --- a/hw/i386/microvm.c
> +++ b/hw/i386/microvm.c
> @@ -637,7 +637,6 @@ GlobalProperty microvm_properties[] = {
>  
>  static void microvm_class_init(ObjectClass *oc, const void *data)
>  {
> -    X86MachineClass *x86mc = X86_MACHINE_CLASS(oc);
>      MicrovmMachineClass *mmc = MICROVM_MACHINE_CLASS(oc);
>      MachineClass *mc = MACHINE_CLASS(oc);
>      HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
> @@ -671,8 +670,6 @@ static void microvm_class_init(ObjectClass *oc, const void *data)
>      hc->unplug_request = microvm_device_unplug_request_cb;
>      hc->unplug = microvm_device_unplug_cb;
>  
> -    x86mc->fwcfg_dma_enabled = true;
> -
>      object_class_property_add(oc, MICROVM_MACHINE_RTC, "OnOffAuto",
>                                microvm_machine_get_rtc,
>                                microvm_machine_set_rtc,
> diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c
> index 6e6b96bc345..bfa7e8f1e83 100644
> --- a/hw/i386/multiboot.c
> +++ b/hw/i386/multiboot.c
> @@ -153,7 +153,6 @@ int load_multiboot(X86MachineState *x86ms,
>                     int kernel_file_size,
>                     uint8_t *header)
>  {
> -    bool multiboot_dma_enabled = X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma_enabled;
>      int i, is_multiboot = 0;
>      uint32_t flags = 0;
>      uint32_t mh_entry_addr;
> @@ -402,11 +401,7 @@ int load_multiboot(X86MachineState *x86ms,
>      fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
>                       sizeof(bootinfo));
>  
> -    if (multiboot_dma_enabled) {
> -        option_rom[nb_option_roms].name = "multiboot_dma.bin";
> -    } else {
> -        option_rom[nb_option_roms].name = "multiboot.bin";

shouldn't we remove "multiboot.bin" as well?

> -    }
> +    option_rom[nb_option_roms].name = "multiboot_dma.bin";
>      option_rom[nb_option_roms].bootindex = 0;
>      nb_option_roms++;
>  
> diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
> index 1b0671c5239..27254a0e9f1 100644
> --- a/hw/i386/x86-common.c
> +++ b/hw/i386/x86-common.c
> @@ -634,7 +634,6 @@ void x86_load_linux(X86MachineState *x86ms,
>                      int acpi_data_size,
>                      bool pvh_enabled)
>  {
> -    bool linuxboot_dma_enabled = X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma_enabled;
>      uint16_t protocol;
>      int setup_size, kernel_size, cmdline_size;
>      int dtb_size, setup_data_offset;
> @@ -993,7 +992,7 @@ void x86_load_linux(X86MachineState *x86ms,
>  
>      option_rom[nb_option_roms].bootindex = 0;
>      option_rom[nb_option_roms].name = "linuxboot.bin";
> -    if (linuxboot_dma_enabled && fw_cfg_dma_enabled(fw_cfg)) {
> +    if (fw_cfg_dma_enabled(fw_cfg)) {
>          option_rom[nb_option_roms].name = "linuxboot_dma.bin";
>      }
>      nb_option_roms++;
> diff --git a/hw/i386/x86.c b/hw/i386/x86.c
> index f80533df1c5..dbf104d60af 100644
> --- a/hw/i386/x86.c
> +++ b/hw/i386/x86.c
> @@ -375,14 +375,12 @@ static void x86_machine_initfn(Object *obj)
>  static void x86_machine_class_init(ObjectClass *oc, const void *data)
>  {
>      MachineClass *mc = MACHINE_CLASS(oc);
> -    X86MachineClass *x86mc = X86_MACHINE_CLASS(oc);
>      NMIClass *nc = NMI_CLASS(oc);
>  
>      mc->cpu_index_to_instance_props = x86_cpu_index_to_props;
>      mc->get_default_cpu_node_id = x86_get_default_cpu_node_id;
>      mc->possible_cpu_arch_ids = x86_possible_cpu_arch_ids;
>      mc->kvm_type = x86_kvm_type;
> -    x86mc->fwcfg_dma_enabled = true;
>      nc->nmi_monitor_handler = x86_nmi;
>  
>      object_class_property_add(oc, X86_MACHINE_SMM, "OnOffAuto",