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In-Reply-To: <61b34ee0-8205-43e0-becf-a4f6c8ff876a@loongson.cn>
From:   Huacai Chen <chenhuacai@kernel.org>
Date:   Fri, 8 Sep 2023 09:54:49 +0800
Message-ID: <CAAhV-H4vhY+Kf2gOB9o0Kp+pv=aEQtr=Uzq6APq1jn2p20ga0w@mail.gmail.com>
Subject: Re: [PATCH v20 28/30] LoongArch: KVM: Enable kvm config and add the makefile
To:     bibo mao <maobibo@loongson.cn>
Cc:     WANG Xuerui <kernel@xen0n.name>,
        Tianrui Zhao <zhaotianrui@loongson.cn>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Paolo Bonzini <pbonzini@redhat.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        loongarch@lists.linux.dev, Jens Axboe <axboe@kernel.dk>,
        Mark Brown <broonie@kernel.org>,
        Alex Deucher <alexander.deucher@amd.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Xi Ruoyao <xry111@xry111.site>,
        kernel test robot <lkp@intel.com>
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On Fri, Sep 8, 2023 at 9:49=E2=80=AFAM bibo mao <maobibo@loongson.cn> wrote=
:
>
>
>
> =E5=9C=A8 2023/9/8 09:40, Huacai Chen =E5=86=99=E9=81=93:
> > On Fri, Sep 8, 2023 at 4:10=E2=80=AFAM WANG Xuerui <kernel@xen0n.name> =
wrote:
> >>
> >>
> >> On 8/31/23 16:30, Tianrui Zhao wrote:
> >>> Enable LoongArch kvm config and add the makefile to support build kvm
> >>> module.
> >>>
> >>> Reviewed-by: Bibo Mao <maobibo@loongson.cn>
> >>> Reported-by: kernel test robot <lkp@intel.com>
> >>> Link: https://lore.kernel.org/oe-kbuild-all/202304131526.iXfLaVZc-lkp=
@intel.com/
> >>> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
> >>> ---
> >>>   arch/loongarch/Kbuild                      |  1 +
> >>>   arch/loongarch/Kconfig                     |  3 ++
> >>>   arch/loongarch/configs/loongson3_defconfig |  2 +
> >>>   arch/loongarch/kvm/Kconfig                 | 45 +++++++++++++++++++=
+++
> >>>   arch/loongarch/kvm/Makefile                | 22 +++++++++++
> >>>   5 files changed, 73 insertions(+)
> >>>   create mode 100644 arch/loongarch/kvm/Kconfig
> >>>   create mode 100644 arch/loongarch/kvm/Makefile
> >>>
> >>> diff --git a/arch/loongarch/Kbuild b/arch/loongarch/Kbuild
> >>> index b01f5cdb27..40be8a1696 100644
> >>> --- a/arch/loongarch/Kbuild
> >>> +++ b/arch/loongarch/Kbuild
> >>> @@ -2,6 +2,7 @@ obj-y +=3D kernel/
> >>>   obj-y +=3D mm/
> >>>   obj-y +=3D net/
> >>>   obj-y +=3D vdso/
> >>> +obj-y +=3D kvm/
> >> Do we want to keep the list alphabetically sorted here?
> > kvm directory can be at last, but I'm afraid that it should be
> >
> > ifdef CONFIG_KVM
> > obj-y +=3D kvm/
> > endif
> Agree, how about this like other architectures.
> obj-$(CONFIG_KVM) +=3D kvm/
This is better, I agree and it can be at last because it is in a
different format from others.

> >
> > If such a guard is unnecessary, then I agree to use alphabetical order.
> Is there any document about "alphabetical order"? I check Kbuild in other
> directories, it is not sorted by alphabetical order.
Yes, there is no hard limit, but alphabetical order is better in some
cases, e.g., avoid duplicate lines.

Huacai
>
> $ cat  arch/riscv/Kbuild
> obj-y +=3D kernel/ mm/ net/
> obj-$(CONFIG_BUILTIN_DTB) +=3D boot/dts/
> obj-y +=3D errata/
> obj-$(CONFIG_KVM) +=3D kvm/
> obj-$(CONFIG_ARCH_HAS_KEXEC_PURGATORY) +=3D purgatory/
> # for cleaning
> subdir- +=3D boot
>
> $ cat arch/arm64/Kbuild
> obj-y                   +=3D kernel/ mm/ net/
> obj-$(CONFIG_KVM)       +=3D kvm/
> obj-$(CONFIG_XEN)       +=3D xen/
> obj-$(subst m,y,$(CONFIG_HYPERV))       +=3D hyperv/
> obj-$(CONFIG_CRYPTO)    +=3D crypto/
>
> # for cleaning
> subdir- +=3D boot
>
>
> Regards
> Bibo Mao
> >
> > Huacai
> >
> >>>
> >>>   # for cleaning
> >>>   subdir- +=3D boot
> >>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> >>> index ecf282dee5..7f2f7ccc76 100644
> >>> --- a/arch/loongarch/Kconfig
> >>> +++ b/arch/loongarch/Kconfig
> >>> @@ -123,6 +123,7 @@ config LOONGARCH
> >>>       select HAVE_KPROBES
> >>>       select HAVE_KPROBES_ON_FTRACE
> >>>       select HAVE_KRETPROBES
> >>> +     select HAVE_KVM
> >>>       select HAVE_MOD_ARCH_SPECIFIC
> >>>       select HAVE_NMI
> >>>       select HAVE_PCI
> >>> @@ -650,3 +651,5 @@ source "kernel/power/Kconfig"
> >>>   source "drivers/acpi/Kconfig"
> >>>
> >>>   endmenu
> >>> +
> >>> +source "arch/loongarch/kvm/Kconfig"
> >>> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loonga=
rch/configs/loongson3_defconfig
> >>> index d64849b4cb..7acb4ae7af 100644
> >>> --- a/arch/loongarch/configs/loongson3_defconfig
> >>> +++ b/arch/loongarch/configs/loongson3_defconfig
> >>> @@ -63,6 +63,8 @@ CONFIG_EFI_ZBOOT=3Dy
> >>>   CONFIG_EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER=3Dy
> >>>   CONFIG_EFI_CAPSULE_LOADER=3Dm
> >>>   CONFIG_EFI_TEST=3Dm
> >>> +CONFIG_VIRTUALIZATION=3Dy
> >>> +CONFIG_KVM=3Dm
> >>>   CONFIG_MODULES=3Dy
> >>>   CONFIG_MODULE_FORCE_LOAD=3Dy
> >>>   CONFIG_MODULE_UNLOAD=3Dy
> >>> diff --git a/arch/loongarch/kvm/Kconfig b/arch/loongarch/kvm/Kconfig
> >>> new file mode 100644
> >>> index 0000000000..bf7d6e7cde
> >>> --- /dev/null
> >>> +++ b/arch/loongarch/kvm/Kconfig
> >>> @@ -0,0 +1,45 @@
> >>> +# SPDX-License-Identifier: GPL-2.0
> >>> +#
> >>> +# KVM configuration
> >>> +#
> >>> +
> >>> +source "virt/kvm/Kconfig"
> >>> +
> >>> +menuconfig VIRTUALIZATION
> >>> +     bool "Virtualization"
> >>> +     help
> >>> +       Say Y here to get to see options for using your Linux host to=
 run
> >>> +       other operating systems inside virtual machines (guests).
> >>> +       This option alone does not add any kernel code.
> >>> +
> >>> +       If you say N, all options in this submenu will be skipped and
> >>> +       disabled.
> >>> +
> >>> +if VIRTUALIZATION
> >>> +
> >>> +config AS_HAS_LVZ_EXTENSION
> >>> +     def_bool $(as-instr,hvcl 0)
> >>> +
> >>> +config KVM
> >>> +     tristate "Kernel-based Virtual Machine (KVM) support"
> >>> +     depends on HAVE_KVM
> >>> +     depends on AS_HAS_LVZ_EXTENSION
> >>> +     select MMU_NOTIFIER
> >>> +     select ANON_INODES
> >>> +     select PREEMPT_NOTIFIERS
> >>> +     select KVM_MMIO
> >>> +     select KVM_GENERIC_DIRTYLOG_READ_PROTECT
> >>> +     select KVM_GENERIC_HARDWARE_ENABLING
> >>> +     select KVM_XFER_TO_GUEST_WORK
> >>> +     select HAVE_KVM_DIRTY_RING_ACQ_REL
> >>> +     select HAVE_KVM_VCPU_ASYNC_IOCTL
> >>> +     select HAVE_KVM_EVENTFD
> >>> +     select SRCU
> >> Make the list of selects also alphabetically sorted?
> >>> +     help
> >>> +       Support hosting virtualized guest machines using hardware
> >>> +       virtualization extensions. You will need a fairly processor
> >>> +       equipped with virtualization extensions.
> >>
> >> The word "fairly" seems extraneous here, and can be simply dropped.
> >>
> >> (I suppose you forgot to delete it after tweaking the original sentenc=
e,
> >> that came from arch/x86/kvm: "You will need a fairly recent processor
> >> ..." -- all LoongArch processors are recent!)
> >>
> >>> +
> >>> +       If unsure, say N.
> >>> +
> >>> +endif # VIRTUALIZATION
> >>> diff --git a/arch/loongarch/kvm/Makefile b/arch/loongarch/kvm/Makefil=
e
> >>> new file mode 100644
> >>> index 0000000000..2335e873a6
> >>> --- /dev/null
> >>> +++ b/arch/loongarch/kvm/Makefile
> >>> @@ -0,0 +1,22 @@
> >>> +# SPDX-License-Identifier: GPL-2.0
> >>> +#
> >>> +# Makefile for LOONGARCH KVM support
> >> "LoongArch" -- you may want to check the entire patch series for such
> >> ALL-CAPS references to LoongArch in natural language paragraphs, they
> >> all want to be spelled "LoongArch".
> >>> +#
> >>> +
> >>> +ccflags-y +=3D -I $(srctree)/$(src)
> >>> +
> >>> +include $(srctree)/virt/kvm/Makefile.kvm
> >>> +
> >>> +obj-$(CONFIG_KVM) +=3D kvm.o
> >>> +
> >>> +kvm-y +=3D main.o
> >>> +kvm-y +=3D vm.o
> >>> +kvm-y +=3D vmid.o
> >>> +kvm-y +=3D tlb.o
> >>> +kvm-y +=3D mmu.o
> >>> +kvm-y +=3D vcpu.o
> >>> +kvm-y +=3D exit.o
> >>> +kvm-y +=3D interrupt.o
> >>> +kvm-y +=3D timer.o
> >>> +kvm-y +=3D switch.o
> >>> +kvm-y +=3D csr_ops.o
> >> I'd suggest sorting this list too to better avoid editing conflicts in
> >> the future.
> >>
> >> --
> >> WANG "xen0n" Xuerui
> >>
> >> Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/
> >>
> >>
>
>