Re: [PATCH v2 6/6] hw/isa/piix: Resolve redundant TYPE_PIIX3_XEN_DEVICE

[Philippe Mathieu-Daudé]

+Markus/Thomas

On 4/1/23 15:44, Bernhard Beschow wrote:
> During the last patches, TYPE_PIIX3_XEN_DEVICE turned into a clone of
> TYPE_PIIX3_DEVICE. Remove this redundancy.
>
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
> ---
>   hw/i386/pc_piix.c             |  4 +---
>   hw/isa/piix.c                 | 20 --------------------
>   include/hw/southbridge/piix.h |  1 -
>   3 files changed, 1 insertion(+), 24 deletions(-)
>
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 5738d9cdca..6b8de3d59d 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -235,8 +235,6 @@ static void pc_init1(MachineState *machine,
>       if (pcmc->pci_enabled) {
>           DeviceState *dev;
>           PCIDevice *pci_dev;
> -        const char *type = xen_enabled() ? TYPE_PIIX3_XEN_DEVICE
> -                                         : TYPE_PIIX3_DEVICE;
>           int i;
>   
>           pci_bus = i440fx_init(pci_type,
> @@ -250,7 +248,7 @@ static void pc_init1(MachineState *machine,
>                                          : pci_slot_get_pirq);
>           pcms->bus = pci_bus;
>   
> -        pci_dev = pci_new_multifunction(-1, true, type);
> +        pci_dev = pci_new_multifunction(-1, true, TYPE_PIIX3_DEVICE);
>           object_property_set_bool(OBJECT(pci_dev), "has-usb",
>                                    machine_usb(machine), &error_abort);
>           object_property_set_bool(OBJECT(pci_dev), "has-acpi",
> diff --git a/hw/isa/piix.c b/hw/isa/piix.c
> index 98e9b12661..e4587352c9 100644
> --- a/hw/isa/piix.c
> +++ b/hw/isa/piix.c
> @@ -33,7 +33,6 @@
>   #include "hw/qdev-properties.h"
>   #include "hw/ide/piix.h"
>   #include "hw/isa/isa.h"
> -#include "hw/xen/xen.h"
>   #include "sysemu/runstate.h"
>   #include "migration/vmstate.h"
>   #include "hw/acpi/acpi_aml_interface.h"
> @@ -465,24 +464,6 @@ static const TypeInfo piix3_info = {
>       .class_init    = piix3_class_init,
>   };
>   
> -static void piix3_xen_class_init(ObjectClass *klass, void *data)
> -{
> -    DeviceClass *dc = DEVICE_CLASS(klass);
> -    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> -
> -    k->realize = piix3_realize;
> -    /* 82371SB PIIX3 PCI-to-ISA bridge (Step A1) */
> -    k->device_id = PCI_DEVICE_ID_INTEL_82371SB_0;
> -    dc->vmsd = &vmstate_piix3;

IIUC, since this device is user-creatable, we can't simply remove it
without going thru the deprecation process. Alternatively we could
add a type alias:

-- >8 --
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 4b0ef65780..d94f7ea369 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -64,6 +64,7 @@ typedef struct QDevAlias
                               QEMU_ARCH_LOONGARCH)
 #define QEMU_ARCH_VIRTIO_CCW (QEMU_ARCH_S390X)
 #define QEMU_ARCH_VIRTIO_MMIO (QEMU_ARCH_M68K)
+#define QEMU_ARCH_XEN (QEMU_ARCH_ARM | QEMU_ARCH_I386)

 /* Please keep this table sorted by typename. */
 static const QDevAlias qdev_alias_table[] = {
@@ -111,6 +112,7 @@ static const QDevAlias qdev_alias_table[] = {
     { "virtio-tablet-device", "virtio-tablet", QEMU_ARCH_VIRTIO_MMIO },
     { "virtio-tablet-ccw", "virtio-tablet", QEMU_ARCH_VIRTIO_CCW },
     { "virtio-tablet-pci", "virtio-tablet", QEMU_ARCH_VIRTIO_PCI },
+    { "PIIX3", "PIIX3-xen", QEMU_ARCH_XEN },
     { }
 };
---

But I'm not sure due to this comment from commit ee46d8a503
(2011-12-22 15:24:20 -0600):

47) /*
48)  * Aliases were a bad idea from the start.  Let's keep them
49)  * from spreading further.
50)  */

Maybe using qdev_alias_table[] during device deprecation is
acceptable?

> -}
> -
> -static const TypeInfo piix3_xen_info = {
> -    .name          = TYPE_PIIX3_XEN_DEVICE,
> -    .parent        = TYPE_PIIX_PCI_DEVICE,
> -    .instance_init = piix3_init,
> -    .class_init    = piix3_xen_class_init,
> -};
> -
>   static void piix4_realize(PCIDevice *dev, Error **errp)
>   {
>       ERRP_GUARD();
> @@ -534,7 +515,6 @@ static void piix3_register_types(void)
>   {
>       type_register_static(&piix_pci_type_info);
>       type_register_static(&piix3_info);
> -    type_register_static(&piix3_xen_info);
>       type_register_static(&piix4_info);
>   }
>   
> diff --git a/include/hw/southbridge/piix.h b/include/hw/southbridge/piix.h
> index 65ad8569da..b1fc94a742 100644
> --- a/include/hw/southbridge/piix.h
> +++ b/include/hw/southbridge/piix.h
> @@ -77,7 +77,6 @@ struct PIIXState {
>   OBJECT_DECLARE_SIMPLE_TYPE(PIIXState, PIIX_PCI_DEVICE)
>   
>   #define TYPE_PIIX3_DEVICE "PIIX3"
> -#define TYPE_PIIX3_XEN_DEVICE "PIIX3-xen"
>   #define TYPE_PIIX4_PCI_DEVICE "piix4-isa"
>   
>   #endif