Re: [PATCH] hw/i386: Fix 'use-legacy-x86-rom' property compatibility

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jul 23, 2025 at 08:27:14AM +0200, Cédric Le Goater wrote:
> Commit 350785d41d8b ("ramfb: Add property to control if load the
> romfile") introduced the `use-legacy-x86-rom` property for the
> `vfio-pci-nohotplug` device, allowing control over VGA BIOS ROM
> loading. However, the property compatibility setting was incorrectly
> applied to the `vfio-pci` device instead, which causes all `vfio-pci`
> devices to fail to load. This change fixes the issue by ensuring the
> property is set on the correct device.
> 
> Fixes: d5fcf0d960d8 ("hw/i386: Add the ramfb romfile compatibility")
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Shaoqin Huang <shahuang@redhat.com>
> Signed-off-by: Cédric Le Goater <clg@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/vfio/types.h   | 2 ++
>  hw/core/machine.c | 2 +-
>  hw/i386/microvm.c | 2 +-
>  hw/i386/pc_piix.c | 2 +-
>  hw/i386/pc_q35.c  | 2 +-
>  hw/vfio/pci.c     | 2 --
>  6 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/vfio/types.h b/hw/vfio/types.h
> index fa20c29b9fbbf51ddad4f6cb0535a70152224a94..c19334ff25ae2f5221f08ed863553ce7f8e3be98 100644
> --- a/hw/vfio/types.h
> +++ b/hw/vfio/types.h
> @@ -18,4 +18,6 @@
>  #define TYPE_VFIO_PCI "vfio-pci"
>  /* TYPE_VFIO_PCI shares struct VFIOPCIDevice. */
>  
> +#define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
> +
>  #endif /* HW_VFIO_VFIO_TYPES_H */
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index d6b2240fc250d2d1194dee62e5356c0c214f1069..bd47527479a7947ca293a47c9a6f49916d24bad3 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -41,7 +41,7 @@ GlobalProperty hw_compat_10_0[] = {
>      { "scsi-hd", "dpofua", "off" },
>      { "vfio-pci", "x-migration-load-config-after-iter", "off" },
>      { "ramfb", "use-legacy-x86-rom", "true"},
> -    { "vfio-pci", "use-legacy-x86-rom", "true" },
> +    { "vfio-pci-nohotplug", "use-legacy-x86-rom", "true" },
>  };
>  const size_t hw_compat_10_0_len = G_N_ELEMENTS(hw_compat_10_0);
>  
> diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
> index d90b69a162007af8af1b8596be590126fb00fb59..94d22a232aca1f82590d80c2ac6cc279bb9ff808 100644
> --- a/hw/i386/microvm.c
> +++ b/hw/i386/microvm.c
> @@ -635,7 +635,7 @@ GlobalProperty microvm_properties[] = {
>       */
>      { "pcie-root-port", "io-reserve", "0" },
>      { TYPE_RAMFB_DEVICE, "use-legacy-x86-rom", "true" },
> -    { TYPE_VFIO_PCI, "use-legacy-x86-rom", "true" },
> +    { TYPE_VFIO_PCI_NOHOTPLUG, "use-legacy-x86-rom", "true" },
>  };
>  
>  static void microvm_class_init(ObjectClass *oc, const void *data)
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index ad5caff3a5d251671db591c68bed3b69a5e45d17..c03324281bdb356e17d434b156e4080865867f4f 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -80,7 +80,7 @@ static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
>  
>  static GlobalProperty pc_piix_compat_defaults[] = {
>      { TYPE_RAMFB_DEVICE, "use-legacy-x86-rom", "true" },
> -    { TYPE_VFIO_PCI, "use-legacy-x86-rom", "true" },
> +    { TYPE_VFIO_PCI_NOHOTPLUG, "use-legacy-x86-rom", "true" },
>  };
>  static const size_t pc_piix_compat_defaults_len =
>      G_N_ELEMENTS(pc_piix_compat_defaults);
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 9b9519fa02d506393058c085178924156e9e0d10..b309b2b378db4741b72828c1f34d2edc2e057a1d 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -69,7 +69,7 @@
>  static GlobalProperty pc_q35_compat_defaults[] = {
>      { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "39" },
>      { TYPE_RAMFB_DEVICE, "use-legacy-x86-rom", "true" },
> -    { TYPE_VFIO_PCI, "use-legacy-x86-rom", "true" },
> +    { TYPE_VFIO_PCI_NOHOTPLUG, "use-legacy-x86-rom", "true" },
>  };
>  static const size_t pc_q35_compat_defaults_len =
>      G_N_ELEMENTS(pc_q35_compat_defaults);
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index e72d514a4cb91946f7c79332492bf5d709c308f2..0c4606d9cb5e163b8c533ed9b89d4d73eafaae24 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -49,8 +49,6 @@
>  #include "vfio-migration-internal.h"
>  #include "vfio-helpers.h"
>  
> -#define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
> -
>  /* Protected by BQL */
>  static KVMRouteChange vfio_route_change;
>  
> -- 
> 2.50.1