Re: [PATCH V2] vhost: do not enable VHOST_MENU by default

[Michael S. Tsirkin]

On Wed, Apr 15, 2020 at 10:43:56AM +0800, Jason Wang wrote:
> We try to keep the defconfig untouched after decoupling CONFIG_VHOST
> out of CONFIG_VIRTUALIZATION in commit 20c384f1ea1a
> ("vhost: refine vhost and vringh kconfig") by enabling VHOST_MENU by
> default. Then the defconfigs can keep enabling CONFIG_VHOST_NET
> without the caring of CONFIG_VHOST.
> 
> But this will leave a "CONFIG_VHOST_MENU=y" in all defconfigs and even
> for the ones that doesn't want vhost. So it actually shifts the
> burdens to the maintainers of all other to add "CONFIG_VHOST_MENU is
> not set". So this patch tries to enable CONFIG_VHOST explicitly in
> defconfigs that enables CONFIG_VHOST_NET and CONFIG_VHOST_VSOCK.
> 
> Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> (s390)
> Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

I rebased this on top of OABI fix since that
seems more orgent to fix.
Pushed to my vhost branch pls take a look and
if possible test.
Thanks!

> ---
> Change since V1:
> - depends on EVENTFD for VHOST
> ---
>  arch/mips/configs/malta_kvm_defconfig  |  1 +
>  arch/powerpc/configs/powernv_defconfig |  1 +
>  arch/powerpc/configs/ppc64_defconfig   |  1 +
>  arch/powerpc/configs/pseries_defconfig |  1 +
>  arch/s390/configs/debug_defconfig      |  1 +
>  arch/s390/configs/defconfig            |  1 +
>  drivers/vhost/Kconfig                  | 26 +++++++++-----------------
>  7 files changed, 15 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/mips/configs/malta_kvm_defconfig b/arch/mips/configs/malta_kvm_defconfig
> index 8ef612552a19..06f0c7a0ca87 100644
> --- a/arch/mips/configs/malta_kvm_defconfig
> +++ b/arch/mips/configs/malta_kvm_defconfig
> @@ -18,6 +18,7 @@ CONFIG_PCI=y
>  CONFIG_VIRTUALIZATION=y
>  CONFIG_KVM=m
>  CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS=y
> +CONFIG_VHOST=m
>  CONFIG_VHOST_NET=m
>  CONFIG_MODULES=y
>  CONFIG_MODULE_UNLOAD=y
> diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig
> index 71749377d164..404245b4594d 100644
> --- a/arch/powerpc/configs/powernv_defconfig
> +++ b/arch/powerpc/configs/powernv_defconfig
> @@ -346,5 +346,6 @@ CONFIG_CRYPTO_DEV_VMX=y
>  CONFIG_VIRTUALIZATION=y
>  CONFIG_KVM_BOOK3S_64=m
>  CONFIG_KVM_BOOK3S_64_HV=m
> +CONFIG_VHOST=m
>  CONFIG_VHOST_NET=m
>  CONFIG_PRINTK_TIME=y
> diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
> index 7e68cb222c7b..4599fc7be285 100644
> --- a/arch/powerpc/configs/ppc64_defconfig
> +++ b/arch/powerpc/configs/ppc64_defconfig
> @@ -61,6 +61,7 @@ CONFIG_ELECTRA_CF=y
>  CONFIG_VIRTUALIZATION=y
>  CONFIG_KVM_BOOK3S_64=m
>  CONFIG_KVM_BOOK3S_64_HV=m
> +CONFIG_VHOST=m
>  CONFIG_VHOST_NET=m
>  CONFIG_OPROFILE=m
>  CONFIG_KPROBES=y
> diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
> index 6b68109e248f..4cad3901b5de 100644
> --- a/arch/powerpc/configs/pseries_defconfig
> +++ b/arch/powerpc/configs/pseries_defconfig
> @@ -321,5 +321,6 @@ CONFIG_CRYPTO_DEV_VMX=y
>  CONFIG_VIRTUALIZATION=y
>  CONFIG_KVM_BOOK3S_64=m
>  CONFIG_KVM_BOOK3S_64_HV=m
> +CONFIG_VHOST=m
>  CONFIG_VHOST_NET=m
>  CONFIG_PRINTK_TIME=y
> diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
> index 0c86ba19fa2b..6ec6e69630d1 100644
> --- a/arch/s390/configs/debug_defconfig
> +++ b/arch/s390/configs/debug_defconfig
> @@ -57,6 +57,7 @@ CONFIG_PROTECTED_VIRTUALIZATION_GUEST=y
>  CONFIG_CMM=m
>  CONFIG_APPLDATA_BASE=y
>  CONFIG_KVM=m
> +CONFIG_VHOST=m
>  CONFIG_VHOST_NET=m
>  CONFIG_VHOST_VSOCK=m
>  CONFIG_OPROFILE=m
> diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
> index 6b27d861a9a3..d1b3bf83d687 100644
> --- a/arch/s390/configs/defconfig
> +++ b/arch/s390/configs/defconfig
> @@ -57,6 +57,7 @@ CONFIG_PROTECTED_VIRTUALIZATION_GUEST=y
>  CONFIG_CMM=m
>  CONFIG_APPLDATA_BASE=y
>  CONFIG_KVM=m
> +CONFIG_VHOST=m
>  CONFIG_VHOST_NET=m
>  CONFIG_VHOST_VSOCK=m
>  CONFIG_OPROFILE=m
> diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
> index e79cbbdfea45..29f171a53d8a 100644
> --- a/drivers/vhost/Kconfig
> +++ b/drivers/vhost/Kconfig
> @@ -12,23 +12,19 @@ config VHOST_RING
>  	  This option is selected by any driver which needs to access
>  	  the host side of a virtio ring.
>  
> -config VHOST
> -	tristate
> +menuconfig VHOST
> +	tristate "Vhost Devices"
> +	depends on EVENTFD
>  	select VHOST_IOTLB
>  	help
> -	  This option is selected by any driver which needs to access
> -	  the core of vhost.
> +	  Enable option to support host kernel or hardware accelerator
> +	  for virtio device.
>  
> -menuconfig VHOST_MENU
> -	bool "VHOST drivers"
> -	default y
> -
> -if VHOST_MENU
> +if VHOST
>  
>  config VHOST_NET
>  	tristate "Host kernel accelerator for virtio net"
> -	depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP)
> -	select VHOST
> +	depends on NET && (TUN || !TUN) && (TAP || !TAP)
>  	---help---
>  	  This kernel module can be loaded in host kernel to accelerate
>  	  guest networking with virtio_net. Not to be confused with virtio_net
> @@ -39,8 +35,7 @@ config VHOST_NET
>  
>  config VHOST_SCSI
>  	tristate "VHOST_SCSI TCM fabric driver"
> -	depends on TARGET_CORE && EVENTFD
> -	select VHOST
> +	depends on TARGET_CORE
>  	default n
>  	---help---
>  	Say M here to enable the vhost_scsi TCM fabric module
> @@ -48,8 +43,7 @@ config VHOST_SCSI
>  
>  config VHOST_VSOCK
>  	tristate "vhost virtio-vsock driver"
> -	depends on VSOCKETS && EVENTFD
> -	select VHOST
> +	depends on VSOCKETS
>  	select VIRTIO_VSOCKETS_COMMON
>  	default n
>  	---help---
> @@ -62,8 +56,6 @@ config VHOST_VSOCK
>  
>  config VHOST_VDPA
>  	tristate "Vhost driver for vDPA-based backend"
> -	depends on EVENTFD
> -	select VHOST
>  	depends on VDPA
>  	help
>  	  This kernel module can be loaded in host kernel to accelerate
> -- 
> 2.20.1