Re: [Qemu-devel] [PATCH] Add a property to disable the floppy controller

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

On 05/14/2015 05:41 PM, Stefano Stabellini wrote:
> Do not change default settings for any machines at the moment: this
> patch does not introduce any changes in behavior unless the user asks
> for no-fdc=on.
Hi,

Agreeing with Paolo on this, maybe we can have an 'fdc' property (enabled by default)
and set fdc=off when we don't want it?

>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>   hw/i386/pc.c         |   27 ++++++++++++++++++++++++---
>   include/hw/i386/pc.h |    2 ++
>   vl.c                 |    4 ++++
>   3 files changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index f31d55e..501609b 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1450,10 +1450,14 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
>       cpu_exit_irq = qemu_allocate_irqs(cpu_request_exit, NULL, 1);
>       DMA_init(0, cpu_exit_irq);
>
> -    for(i = 0; i < MAX_FD; i++) {
> -        fd[i] = drive_get(IF_FLOPPY, 0, i);
> +    *floppy = NULL;
> +    if (!object_property_get_bool(qdev_get_machine(),
> +                PC_MACHINE_NO_FDC, &error_abort)) {
> +        for (i = 0; i < MAX_FD; i++) {
> +            fd[i] = drive_get(IF_FLOPPY, 0, i);
> +        }
> +        *floppy = fdctrl_init_isa(isa_bus, fd);
>       }
> -    *floppy = fdctrl_init_isa(isa_bus, fd);
>   }
>
>   void pc_nic_init(ISABus *isa_bus, PCIBus *pci_bus)
> @@ -1797,6 +1801,20 @@ static bool pc_machine_get_aligned_dimm(Object *obj, Error **errp)
>       return pcms->enforce_aligned_dimm;
>   }
>
> +static bool pc_machine_get_no_fdc(Object *obj, Error **errp)
> +{
> +    PCMachineState *pcms = PC_MACHINE(obj);
> +
> +    return pcms->no_fdc;
> +}
> +
> +static void pc_machine_set_no_fdc(Object *obj, bool value, Error **errp)
> +{
> +    PCMachineState *pcms = PC_MACHINE(obj);
> +
> +    pcms->no_fdc = value;
> +}
> +
>   static void pc_machine_initfn(Object *obj)
>   {
>       PCMachineState *pcms = PC_MACHINE(obj);
> @@ -1820,6 +1838,9 @@ static void pc_machine_initfn(Object *obj)
>       object_property_add_bool(obj, PC_MACHINE_ENFORCE_ALIGNED_DIMM,
>                                pc_machine_get_aligned_dimm,
>                                NULL, NULL);
> +    object_property_add_bool(obj, PC_MACHINE_NO_FDC,
> +                             pc_machine_get_no_fdc, pc_machine_set_no_fdc,
> +                             NULL);
>   }
>
>   static void pc_machine_class_init(ObjectClass *oc, void *data)
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 69d9cf8..93b2442 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -41,6 +41,7 @@ struct PCMachineState {
>       uint64_t max_ram_below_4g;
>       OnOffAuto vmport;
>       bool enforce_aligned_dimm;
> +    bool no_fdc;
>   };
>
>   #define PC_MACHINE_ACPI_DEVICE_PROP "acpi-device"
> @@ -48,6 +49,7 @@ struct PCMachineState {
>   #define PC_MACHINE_MAX_RAM_BELOW_4G "max-ram-below-4g"
>   #define PC_MACHINE_VMPORT           "vmport"
>   #define PC_MACHINE_ENFORCE_ALIGNED_DIMM "enforce-aligned-dimm"
> +#define PC_MACHINE_NO_FDC "no-fdc"
>
>   /**
>    * PCMachineClass:
> diff --git a/vl.c b/vl.c
> index 91411c1..81d80ae 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -387,6 +387,10 @@ static QemuOptsList qemu_machine_opts = {
>               .name = "iommu",
>               .type = QEMU_OPT_BOOL,
>               .help = "Set on/off to enable/disable Intel IOMMU (VT-d)",
> +        },{
> +            .name = PC_MACHINE_NO_FDC,
> +            .type = QEMU_OPT_BOOL,
> +            .help = "do not emulate a floppy controller",
The machine properties are "dynamic" now, this list
should be empty, including the "iommu" above. Am I missing something ?

By the way, there is a problem with this, we have to add the
new properties to util/qemu-config.c.

Thanks,
Marcel

>           },
>           { /* End of list */ }
>       },
>