Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20191008131508.21189-1-liuw@liuw.name>
In-Reply-To: <20191008131508.21189-1-liuw@liuw.name>
From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Wed, 9 Oct 2019 01:03:19 +0900
Message-ID: <CAK7LNAQpszkwtp2mAfoPajkRi0SHPspivWn9sUsxO0oua2X6NQ@mail.gmail.com>
Subject: Re: [PATCH RFC] kconfig: add hvconfig for Linux on Hyper-V
To:     Wei Liu <wei.liu@kernel.org>
Cc:     Linux on Hyper-V List <linux-hyperv@vger.kernel.org>,
        Linux Kernel List <linux-kernel@vger.kernel.org>,
        Linux Kconfig List <linux-kbuild@vger.kernel.org>,
        Wei Liu <liuwe@microsoft.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Oct 8, 2019 at 10:15 PM Wei Liu <wei.liu@kernel.org> wrote:
>
> From: Wei Liu <liuwe@microsoft.com>
>
> Add an config file snippet which enalbes additional options useful for
> running the kernel in a Hyper-V guest.
>
> The expected use case is a user provides an existing config file then
> executes `make hvconfig`. It will merge those options with the
> provided config file.
>
> Based on similar concept for Xen and KVM.
>
> Signed-off-by: Wei Liu <liuwe@microsoft.com>
> ---
> RFC: I only tested this on x86.  Although the config options included in
> hv_guest.config don't seem to be arch-specific, we should probably
> move the ones not yet implemented on Arm to an x86 specific config
> file.
> ---
>  Documentation/admin-guide/README.rst |  3 +++
>  kernel/configs/hv_guest.config       | 33 ++++++++++++++++++++++++++++
>  scripts/kconfig/Makefile             |  5 +++++
>  3 files changed, 41 insertions(+)
>  create mode 100644 kernel/configs/hv_guest.config
>
> diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst
> index cc6151fc0845..d5f4389a7a2f 100644
> --- a/Documentation/admin-guide/README.rst
> +++ b/Documentation/admin-guide/README.rst
> @@ -224,6 +224,9 @@ Configuring the kernel
>       "make xenconfig"   Enable additional options for xen dom0 guest kernel
>                          support.
>
> +     "make hvconfig"    Enable additional options for Hyper-V guest kernel
> +                        support.
> +
>       "make tinyconfig"  Configure the tiniest possible kernel.
>
>     You can find more information on using the Linux kernel config tools
> diff --git a/kernel/configs/hv_guest.config b/kernel/configs/hv_guest.config
> new file mode 100644
> index 000000000000..0e71e34a2d4d
> --- /dev/null
> +++ b/kernel/configs/hv_guest.config
> @@ -0,0 +1,33 @@
> +CONFIG_NET=y
> +CONFIG_NET_CORE=y
> +CONFIG_NETDEVICES=y
> +CONFIG_BLOCK=y
> +CONFIG_BLK_DEV=y
> +CONFIG_NETWORK_FILESYSTEMS=y
> +CONFIG_INET=y
> +CONFIG_TTY=y
> +CONFIG_SERIAL_8250=y
> +CONFIG_SERIAL_8250_CONSOLE=y
> +CONFIG_IP_PNP=y
> +CONFIG_IP_PNP_DHCP=y
> +CONFIG_BINFMT_ELF=y
> +CONFIG_PCI=y
> +CONFIG_PCI_MSI=y
> +CONFIG_DEBUG_KERNEL=y
> +CONFIG_VIRTUALIZATION=y
> +CONFIG_HYPERVISOR_GUEST=y
> +CONFIG_PARAVIRT=y
> +CONFIG_HYPERV=y
> +CONFIG_HYPERV_VSOCKETS=y
> +CONFIG_PCI_HYPERV=y
> +CONFIG_PCI_HYPERV_INTERFACE=y
> +CONFIG_HYPERV_STORAGE=y
> +CONFIG_HYPERV_NET=y
> +CONFIG_HYPERV_KEYBOARD=y
> +CONFIG_FB_HYPERV=y
> +CONFIG_HID_HYPERV_MOUSE=y
> +CONFIG_HYPERV=y
> +CONFIG_HYPERV_TIMER=y
> +CONFIG_HYPERV_UTILS=y
> +CONFIG_HYPERV_BALLOON=y
> +CONFIG_HYPERV_IOMMU=y
> diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
> index ef2f2336c469..2ee46301b22e 100644
> --- a/scripts/kconfig/Makefile
> +++ b/scripts/kconfig/Makefile
> @@ -104,6 +104,10 @@ PHONY += xenconfig
>  xenconfig: xen.config
>         @:
>
> +PHONY += hvconfig
> +hvconfig: hv_guest.config
> +       @:
> +


Does this need to be hooked up to kconfig Makefile?

In my understanding, this code provides
"make hvconfig" as a shorthand for "make hv_guest.config"

Please do not do this.


See "xenconfig" as a bad example.

"make xenconfig" is a shorthand of "make xen.config".
This exists to save just one character typing.


If I allow this, people would push more and more random pointless shorthands,
which are essentially unrelated to kconfig.


kvmconfig and xenconfig are just historical mistakes.


Please drop the changes to scripts/kconfig/Makefile.

Also, please do not use misleading "kconfig:" for the subject prefix.
You can use the subject prefix "hyper-v:" or something.


Thanks.


>  PHONY += tinyconfig
>  tinyconfig:
>         $(Q)$(MAKE) -f $(srctree)/Makefile allnoconfig tiny.config
> @@ -138,6 +142,7 @@ help:
>         @echo  '                    default value without prompting'
>         @echo  '  kvmconfig       - Enable additional options for kvm guest kernel support'
>         @echo  '  xenconfig       - Enable additional options for xen dom0 and guest kernel support'
> +       @echo  '  hvconfig        - Enable additional options for Hyper-V guest kernel support'
>         @echo  '  tinyconfig      - Configure the tiniest possible kernel'
>         @echo  '  testconfig      - Run Kconfig unit tests (requires python3 and pytest)'
>
> --
> 2.20.1
>


-- 
Best Regards
Masahiro Yamada