Re: [RFC PATCH 2/2] hw/arm/raspi: Restrict BCM2835 / BCM2836 SoC to TCG

[Luc Michel <luc@lmichel.fr>]

Hi Philippe,

On 16:14 Sun 31 Jan     , Philippe Mathieu-Daudé wrote:
> KVM requires the target cpu to be at least ARMv8 architecture
> (support on ARMv7 has been dropped in commit 82bf7ae84ce:
> "target/arm: Remove KVM support for 32-bit Arm hosts").
Wow, is there absolutely no way to do that then? What about using an
ARMv8 and starting in AArch32 mode? Is that possible with KVM? I guess
it might not be strictly identical as spawning the "real" CPU...

> 
> From the various SoC used by the Raspberry Pi machines, only
> the BCM2837 is an ARMv8 (Cortex-A53).
> 
> Restrict the BCM2835 (ARM1176) and BCM2836 (Cortex-A7) to TCG.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  hw/arm/bcm2836.c | 6 ++++++
>  hw/arm/raspi.c   | 4 ++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/hw/arm/bcm2836.c b/hw/arm/bcm2836.c
> index fd16ed87c40..3051764f2dc 100644
> --- a/hw/arm/bcm2836.c
> +++ b/hw/arm/bcm2836.c
> @@ -89,6 +89,7 @@ static bool bcm283x_common_realize(DeviceState *dev, Error **errp)
>      return true;
>  }
>  
> +#ifdef CONFIG_TCG
I'm not sure it's enough. TCG and KVM can be enabled in the same
binary. You'll have to perform a runtime check here I think.

>  static void bcm2835_realize(DeviceState *dev, Error **errp)
>  {
>      BCM283XState *s = BCM283X(dev);
> @@ -107,6 +108,7 @@ static void bcm2835_realize(DeviceState *dev, Error **errp)
>      sysbus_connect_irq(SYS_BUS_DEVICE(&s->peripherals), 1,
>              qdev_get_gpio_in(DEVICE(&s->cpu[0].core), ARM_CPU_FIQ));
>  }
> +#endif /* CONFIG_TCG */
>  
>  static void bcm2836_realize(DeviceState *dev, Error **errp)
>  {
> @@ -178,6 +180,7 @@ static void bcm283x_class_init(ObjectClass *oc, void *data)
>      dc->user_creatable = false;
>  }
>  
> +#ifdef CONFIG_TCG
>  static void bcm2835_class_init(ObjectClass *oc, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(oc);
> @@ -201,6 +204,7 @@ static void bcm2836_class_init(ObjectClass *oc, void *data)
>      bc->clusterid = 0xf;
>      dc->realize = bcm2836_realize;
>  };
> +#endif /* CONFIG_TCG */
>  
>  #ifdef TARGET_AARCH64
>  static void bcm2837_class_init(ObjectClass *oc, void *data)
> @@ -227,6 +231,7 @@ static const TypeInfo bcm283x_types[] = {
>          .class_init     = bcm283x_class_init,
>          .abstract       = true,
>      },
> +#ifdef CONFIG_TCG
>      {
>          .name           = TYPE_BCM2835,
>          .parent         = TYPE_BCM283X,
> @@ -236,6 +241,7 @@ static const TypeInfo bcm283x_types[] = {
>          .parent         = TYPE_BCM283X,
>          .class_init     = bcm2836_class_init,
>      },
> +#endif /* CONFIG_TCG */
>  #ifdef TARGET_AARCH64
>      {
>          .name           = TYPE_BCM2837,
> diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
> index dce966a4dd8..cfa15504d9c 100644
> --- a/hw/arm/raspi.c
> +++ b/hw/arm/raspi.c
> @@ -319,6 +319,7 @@ static void raspi_machine_class_common_init(MachineClass *mc,
>      mc->default_ram_id = "ram";
>  };
>  
> +#ifdef CONFIG_TCG
>  static void raspi0_machine_class_init(ObjectClass *oc, void *data)
>  {
>      MachineClass *mc = MACHINE_CLASS(oc);
> @@ -346,6 +347,7 @@ static void raspi2b_machine_class_init(ObjectClass *oc, void *data)
>      rmc->board_rev = 0xa21041;
>      raspi_machine_class_common_init(mc, rmc->board_rev);
>  };
> +#endif /* CONFIG_TCG */
>  
>  #ifdef TARGET_AARCH64
>  static void raspi3ap_machine_class_init(ObjectClass *oc, void *data)
> @@ -376,6 +378,7 @@ static const TypeInfo raspi_machine_types[] = {
>          .class_size     = sizeof(RaspiMachineClass),
>          .abstract       = true,
>      },
> +#ifdef CONFIG_TCG
>      {
>          .name           = MACHINE_TYPE_NAME("raspi0"),
>          .parent         = TYPE_RASPI_MACHINE,
> @@ -389,6 +392,7 @@ static const TypeInfo raspi_machine_types[] = {
>          .parent         = TYPE_RASPI_MACHINE,
>          .class_init     = raspi2b_machine_class_init,
>      },
> +#endif /* CONFIG_TCG */
>  #ifdef TARGET_AARCH64
>      {
>          .name           = MACHINE_TYPE_NAME("raspi3ap"),
> -- 
> 2.26.2
> 

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