Re: [PATCH 01/10] hw/mem/nvdimm: Use Kconfig 'imply' instead of 'depends on'

From: Bin Meng <bmeng.cn@gmail.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
	Eduardo Habkost <ehabkost@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Richard Henderson <richard.henderson@linaro.org>,
	Greg Kurz <groug@kaod.org>,
	"qemu-devel@nongnu.org Developers" <qemu-devel@nongnu.org>,
	"open list:ARM TCG CPUs" <qemu-arm@nongnu.org>,
	"open list:PowerPC TCG CPUs" <qemu-ppc@nongnu.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Igor Mammedov <imammedo@redhat.com>,
	David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [PATCH 01/10] hw/mem/nvdimm: Use Kconfig 'imply' instead of 'depends on'
Date: Fri, 14 May 2021 11:02:54 +0800	[thread overview]
Message-ID: <CAEUhbmW0h+kvTyrDjum8pVmm9sjn9mkTf-bLRRJqf-ocs1mgqg@mail.gmail.com> (raw)
In-Reply-To: <20210513163858.3928976-2-philmd@redhat.com>

On Fri, May 14, 2021 at 12:53 AM Philippe Mathieu-Daudé
<philmd@redhat.com> wrote:
>
> Per the kconfig.rst:
>
>   A device should be listed [...] ``imply`` if (depending on
>   the QEMU command line) the board may or  may not be started
>   without it.
>
> This is the case with the NVDIMM device (it is certainly possible
> to start a machine without NVDIMM) , so use the 'imply' weak
> reverse dependency to select the symbol.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  default-configs/devices/ppc64-softmmu.mak | 1 -
>  hw/arm/Kconfig                            | 1 +
>  hw/i386/Kconfig                           | 1 +
>  hw/mem/Kconfig                            | 2 --
>  hw/ppc/Kconfig                            | 1 +
>  5 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/default-configs/devices/ppc64-softmmu.mak b/default-configs/devices/ppc64-softmmu.mak
> index ae0841fa3a1..cca52665d90 100644
> --- a/default-configs/devices/ppc64-softmmu.mak
> +++ b/default-configs/devices/ppc64-softmmu.mak
> @@ -8,4 +8,3 @@ CONFIG_POWERNV=y
>
>  # For pSeries
>  CONFIG_PSERIES=y
> -CONFIG_NVDIMM=y

I think only removing this one makes sense. I fail to see any
difference of other changes in this patch.

> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> index b887f6a5b17..67723d9ea6a 100644
> --- a/hw/arm/Kconfig
> +++ b/hw/arm/Kconfig
> @@ -6,6 +6,7 @@ config ARM_VIRT
>      imply VFIO_PLATFORM
>      imply VFIO_XGMAC
>      imply TPM_TIS_SYSBUS
> +    imply NVDIMM
>      select ARM_GIC
>      select ACPI
>      select ARM_SMMUV3
> diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
> index 7f91f30877f..66838fa397b 100644
> --- a/hw/i386/Kconfig
> +++ b/hw/i386/Kconfig
> @@ -23,6 +23,7 @@ config PC
>      imply TPM_TIS_ISA
>      imply VGA_PCI
>      imply VIRTIO_VGA
> +    imply NVDIMM
>      select FDC
>      select I8259
>      select I8254
> diff --git a/hw/mem/Kconfig b/hw/mem/Kconfig
> index a0ef2cf648e..8b19fdc49f1 100644
> --- a/hw/mem/Kconfig
> +++ b/hw/mem/Kconfig
> @@ -7,6 +7,4 @@ config MEM_DEVICE
>
>  config NVDIMM
>      bool
> -    default y
> -    depends on (PC || PSERIES || ARM_VIRT)
>      select MEM_DEVICE
> diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
> index e51e0e5e5ac..66e0b15d9ef 100644
> --- a/hw/ppc/Kconfig
> +++ b/hw/ppc/Kconfig
> @@ -3,6 +3,7 @@ config PSERIES
>      imply PCI_DEVICES
>      imply TEST_DEVICES
>      imply VIRTIO_VGA
> +    imply NVDIMM
>      select DIMM
>      select PCI
>      select SPAPR_VSCSI

Regards,
Bin