Re: [PATCH v4] xen/arm: Allow QEMU platform to be built with GICv2

[Bertrand Marquis <Bertrand.Marquis@arm.com>]

Hi,

> On 17 Jan 2022, at 06:40, Dongjiu Geng <gengdongjiu1@gmail.com> wrote:
> 
> It turns out that QEMU has been supporting GICv2 virtualization since
> v3.1.0. So remove the dependencies on GICv3. If we want to use GICv3,
> we can select the QEMU_LEGACY configuration.

I am bit puzzled by this change introducing a legacy option actually selecting the newest GIC interface.

Can’t we do the opposite and introduce a QEMU_GICV2 instead ?

Also why do we need to remove gic-v3 support ? The code should actually select which gic to use depending on the device tree.

Regards
Bertrand

> 
> Signed-off-by: Dongjiu Geng <gengdongjiu1@gmail.com>
> ---
> xen/arch/arm/platforms/Kconfig | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kconfig
> index c93a6b2756..41e82a42ee 100644
> --- a/xen/arch/arm/platforms/Kconfig
> +++ b/xen/arch/arm/platforms/Kconfig
> @@ -13,7 +13,15 @@ config ALL_PLAT
> 	automatically select any of the related drivers.
> 
> config QEMU
> -	bool "QEMU aarch virt machine support"
> +	bool "QEMU aarch virt machine support >= v3.1.0"
> +	depends on ARM_64
> +	select HAS_PL011
> +	---help---
> +	Enable all the required drivers for QEMU aarch64 virt emulated
> +	machine.
> +
> +config QEMU_LEGACY
> +	bool "QEMU aarch virt machine support < v3.1.0"
> 	depends on ARM_64
> 	select GICV3
> 	select HAS_PL011
> -- 
> 2.25.1
>