Re: [PATCH v2] ramfb: Add property to control if load the romfile

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Jun 06, 2025 at 03:02:34AM -0400, Shaoqin Huang wrote:
> Now the ramfb will load the vgabios-ramfb.bin unconditionally, but only
> the x86 need the vgabios-ramfb.bin, this can cause that when use the
> release package on arm64 it can't find the vgabios-ramfb.bin.
> 
> Because only seabios will use the vgabios-ramfb.bin, load the rom logic
> is x86-specific. For other !x86 platforms, the edk2 ships an EFI driver
> for ramfb, so they don't need to load the romfile.
> 
> So add a new property use_legacy_x86_rom in both ramfb and vfio_pci
> device, because the vfio display also use the ramfb_setup() to load
> the vgabios-ramfb.bin file.
> 
> After have this property, the machine type can set the compatibility to
> not load the vgabios-ramfb.bin if the arch doesn't need it.

Can you make this a series, with an additional patch that updates the
current in-dev machine types to use this new property, so we're clear
about the proposed usage.

> 
> Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
> ---
>  hw/display/ramfb-standalone.c | 4 +++-
>  hw/display/ramfb-stubs.c      | 2 +-
>  hw/display/ramfb.c            | 6 ++++--
>  hw/vfio/display.c             | 4 ++--
>  hw/vfio/pci.c                 | 1 +
>  hw/vfio/pci.h                 | 1 +
>  include/hw/display/ramfb.h    | 2 +-
>  7 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/display/ramfb-standalone.c b/hw/display/ramfb-standalone.c
> index 1be106b57f..af1175bf96 100644
> --- a/hw/display/ramfb-standalone.c
> +++ b/hw/display/ramfb-standalone.c
> @@ -17,6 +17,7 @@ struct RAMFBStandaloneState {
>      QemuConsole *con;
>      RAMFBState *state;
>      bool migrate;
> +    bool use_legacy_x86_rom;
>  };
>  
>  static void display_update_wrapper(void *dev)
> @@ -39,7 +40,7 @@ static void ramfb_realizefn(DeviceState *dev, Error **errp)
>      RAMFBStandaloneState *ramfb = RAMFB(dev);
>  
>      ramfb->con = graphic_console_init(dev, 0, &wrapper_ops, dev);
> -    ramfb->state = ramfb_setup(errp);
> +    ramfb->state = ramfb_setup(ramfb->use_legacy_x86_rom, errp);
>  }
>  
>  static bool migrate_needed(void *opaque)
> @@ -62,6 +63,7 @@ static const VMStateDescription ramfb_dev_vmstate = {
>  
>  static const Property ramfb_properties[] = {
>      DEFINE_PROP_BOOL("x-migrate", RAMFBStandaloneState, migrate,  true),
> +    DEFINE_PROP_BOOL("use-legacy-x86-rom", RAMFBStandaloneState, use_legacy_x86_rom, true),
>  };
>  
>  static void ramfb_class_initfn(ObjectClass *klass, void *data)
> diff --git a/hw/display/ramfb-stubs.c b/hw/display/ramfb-stubs.c
> index cf64733b10..b83551357b 100644
> --- a/hw/display/ramfb-stubs.c
> +++ b/hw/display/ramfb-stubs.c
> @@ -8,7 +8,7 @@ void ramfb_display_update(QemuConsole *con, RAMFBState *s)
>  {
>  }
>  
> -RAMFBState *ramfb_setup(Error **errp)
> +RAMFBState *ramfb_setup(bool romfile, Error **errp)
>  {
>      error_setg(errp, "ramfb support not available");
>      return NULL;
> diff --git a/hw/display/ramfb.c b/hw/display/ramfb.c
> index 8c0f907673..9a17d97d07 100644
> --- a/hw/display/ramfb.c
> +++ b/hw/display/ramfb.c
> @@ -135,7 +135,7 @@ const VMStateDescription ramfb_vmstate = {
>      }
>  };
>  
> -RAMFBState *ramfb_setup(Error **errp)
> +RAMFBState *ramfb_setup(bool romfile, Error **errp)
>  {
>      FWCfgState *fw_cfg = fw_cfg_find();
>      RAMFBState *s;
> @@ -147,7 +147,9 @@ RAMFBState *ramfb_setup(Error **errp)
>  
>      s = g_new0(RAMFBState, 1);
>  
> -    rom_add_vga("vgabios-ramfb.bin");
> +    if (romfile) {
> +        rom_add_vga("vgabios-ramfb.bin");
> +    }
>      fw_cfg_add_file_callback(fw_cfg, "etc/ramfb",
>                               NULL, ramfb_fw_cfg_write, s,
>                               &s->cfg, sizeof(s->cfg), false);
> diff --git a/hw/vfio/display.c b/hw/vfio/display.c
> index ea87830fe0..8bfd8eb1e3 100644
> --- a/hw/vfio/display.c
> +++ b/hw/vfio/display.c
> @@ -365,7 +365,7 @@ static bool vfio_display_dmabuf_init(VFIOPCIDevice *vdev, Error **errp)
>                                            &vfio_display_dmabuf_ops,
>                                            vdev);
>      if (vdev->enable_ramfb) {
> -        vdev->dpy->ramfb = ramfb_setup(errp);
> +        vdev->dpy->ramfb = ramfb_setup(vdev->use_legacy_x86_rom, errp);
>          if (!vdev->dpy->ramfb) {
>              return false;
>          }
> @@ -494,7 +494,7 @@ static bool vfio_display_region_init(VFIOPCIDevice *vdev, Error **errp)
>                                            &vfio_display_region_ops,
>                                            vdev);
>      if (vdev->enable_ramfb) {
> -        vdev->dpy->ramfb = ramfb_setup(errp);
> +        vdev->dpy->ramfb = ramfb_setup(vdev->use_legacy_x86_rom, errp);
>          if (!vdev->dpy->ramfb) {
>              return false;
>          }
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 7f1532fbed..4e4759c954 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3564,6 +3564,7 @@ static const TypeInfo vfio_pci_dev_info = {
>  
>  static const Property vfio_pci_dev_nohotplug_properties[] = {
>      DEFINE_PROP_BOOL("ramfb", VFIOPCIDevice, enable_ramfb, false),
> +    DEFINE_PROP_BOOL("use_legacy_x86_rom", VFIOPCIDevice, use_legacy_x86_rom, true),
>      DEFINE_PROP_ON_OFF_AUTO("x-ramfb-migrate", VFIOPCIDevice, ramfb_migrate,
>                              ON_OFF_AUTO_AUTO),
>  };
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index d94ecaba68..713956157e 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -177,6 +177,7 @@ struct VFIOPCIDevice {
>      bool no_kvm_ioeventfd;
>      bool no_vfio_ioeventfd;
>      bool enable_ramfb;
> +    bool use_legacy_x86_rom;
>      OnOffAuto ramfb_migrate;
>      bool defer_kvm_irq_routing;
>      bool clear_parent_atomics_on_exit;
> diff --git a/include/hw/display/ramfb.h b/include/hw/display/ramfb.h
> index a7e0019144..172aa6dc89 100644
> --- a/include/hw/display/ramfb.h
> +++ b/include/hw/display/ramfb.h
> @@ -6,7 +6,7 @@
>  /* ramfb.c */
>  typedef struct RAMFBState RAMFBState;
>  void ramfb_display_update(QemuConsole *con, RAMFBState *s);
> -RAMFBState *ramfb_setup(Error **errp);
> +RAMFBState *ramfb_setup(bool romfile, Error **errp);
>  
>  extern const VMStateDescription ramfb_vmstate;
>  
> -- 
> 2.40.1
> 

With regards,
Daniel
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