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

[Shaoqin Huang]

Hi Daniel,

On 6/6/25 3:52 PM, Daniel P. Berrangé wrote:

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.

Ok. Thanks for notification. I will update it in the version 3.

Signed-off-by: Shaoqin Huang <shahu...@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

--
Shaoqin