On 2020/4/1 下午10:13, Michael S. Tsirkin wrote: > On Wed, Apr 01, 2020 at 10:08:59PM +0800, Jason Wang wrote: >> On 2020/4/1 下午9:22, Michael S. Tsirkin wrote: >>> On Thu, Mar 26, 2020 at 10:01:17PM +0800, Jason Wang wrote: >>>> Currently, CONFIG_VHOST depends on CONFIG_VIRTUALIZATION. But vhost is >>>> not necessarily for VM since it's a generic userspace and kernel >>>> communication protocol. Such dependency may prevent archs without >>>> virtualization support from using vhost. >>>> >>>> To solve this, a dedicated vhost menu is created under drivers so >>>> CONIFG_VHOST can be decoupled out of CONFIG_VIRTUALIZATION. >>>> >>>> While at it, also squash Kconfig.vringh into vhost Kconfig file. This >>>> avoids the trick of conditional inclusion from VOP or CAIF. Then it >>>> will be easier to introduce new vringh users and common dependency for >>>> both vringh and vhost. >>>> >>>> Signed-off-by: Jason Wang >>> Is this just so we can drop the dependency on CONFIG_VIRTUALIZATION? >>> If yes what happens if we drop this patch? >> >> The problem is that then VHOST_RING must depend on CONFIG_VIRTUALIZATION >> (which enable VHOST_IOTLB) to work. >> >> But it looks to me CAIF and VOP doesn't requires CONFIG_VIRTUALIZATION. > How about stubs for IOTLB so VHOST_RING does not depend on VHOST_IOTLB? That could work. > I'm pretty sure neither user of vringh can actually use IOTLB, it's a > software only thing. Right. > >>> Given the impact it had I'd like to defer it till next release if >>> possible. >>> >>> >>>> --- >>>> arch/arm/kvm/Kconfig | 2 -- >>>> arch/arm64/kvm/Kconfig | 2 -- >>>> arch/mips/kvm/Kconfig | 2 -- >>>> arch/powerpc/kvm/Kconfig | 2 -- >>>> arch/s390/kvm/Kconfig | 4 ---- >>>> arch/x86/kvm/Kconfig | 4 ---- >>>> drivers/Kconfig | 2 ++ >>>> drivers/misc/mic/Kconfig | 4 ---- >>>> drivers/net/caif/Kconfig | 4 ---- >>>> drivers/vhost/Kconfig | 23 ++++++++++++++--------- >>>> drivers/vhost/Kconfig.vringh | 6 ------ >>>> 11 files changed, 16 insertions(+), 39 deletions(-) >>>> delete mode 100644 drivers/vhost/Kconfig.vringh >>>> >>>> diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig >>>> index f591026347a5..be97393761bf 100644 >>>> --- a/arch/arm/kvm/Kconfig >>>> +++ b/arch/arm/kvm/Kconfig >>>> @@ -54,6 +54,4 @@ config KVM_ARM_HOST >>>> ---help--- >>>> Provides host support for ARM processors. >>>> -source "drivers/vhost/Kconfig" >>>> - >>>> endif # VIRTUALIZATION >>>> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig >>>> index a475c68cbfec..449386d76441 100644 >>>> --- a/arch/arm64/kvm/Kconfig >>>> +++ b/arch/arm64/kvm/Kconfig >>>> @@ -64,6 +64,4 @@ config KVM_ARM_PMU >>>> config KVM_INDIRECT_VECTORS >>>> def_bool KVM && (HARDEN_BRANCH_PREDICTOR || HARDEN_EL2_VECTORS) >>>> -source "drivers/vhost/Kconfig" >>>> - >>>> endif # VIRTUALIZATION >>>> diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig >>>> index eac25aef21e0..b91d145aa2d5 100644 >>>> --- a/arch/mips/kvm/Kconfig >>>> +++ b/arch/mips/kvm/Kconfig >>>> @@ -72,6 +72,4 @@ config KVM_MIPS_DEBUG_COP0_COUNTERS >>>> If unsure, say N. >>>> -source "drivers/vhost/Kconfig" >>>> - >>>> endif # VIRTUALIZATION >>>> diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig >>>> index 711fca9bc6f0..12885eda324e 100644 >>>> --- a/arch/powerpc/kvm/Kconfig >>>> +++ b/arch/powerpc/kvm/Kconfig >>>> @@ -204,6 +204,4 @@ config KVM_XIVE >>>> default y >>>> depends on KVM_XICS && PPC_XIVE_NATIVE && KVM_BOOK3S_HV_POSSIBLE >>>> -source "drivers/vhost/Kconfig" >>>> - >>>> endif # VIRTUALIZATION >>>> diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig >>>> index d3db3d7ed077..def3b60f1fe8 100644 >>>> --- a/arch/s390/kvm/Kconfig >>>> +++ b/arch/s390/kvm/Kconfig >>>> @@ -55,8 +55,4 @@ config KVM_S390_UCONTROL >>>> If unsure, say N. >>>> -# OK, it's a little counter-intuitive to do this, but it puts it neatly under >>>> -# the virtualization menu. >>>> -source "drivers/vhost/Kconfig" >>>> - >>>> endif # VIRTUALIZATION >>>> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig >>>> index 991019d5eee1..0dfe70e17af9 100644 >>>> --- a/arch/x86/kvm/Kconfig >>>> +++ b/arch/x86/kvm/Kconfig >>>> @@ -94,8 +94,4 @@ config KVM_MMU_AUDIT >>>> This option adds a R/W kVM module parameter 'mmu_audit', which allows >>>> auditing of KVM MMU events at runtime. >>>> -# OK, it's a little counter-intuitive to do this, but it puts it neatly under >>>> -# the virtualization menu. >>>> -source "drivers/vhost/Kconfig" >>>> - >>>> endif # VIRTUALIZATION >>>> diff --git a/drivers/Kconfig b/drivers/Kconfig >>>> index 8befa53f43be..7a6d8b2b68b4 100644 >>>> --- a/drivers/Kconfig >>>> +++ b/drivers/Kconfig >>>> @@ -138,6 +138,8 @@ source "drivers/virt/Kconfig" >>>> source "drivers/virtio/Kconfig" >>>> +source "drivers/vhost/Kconfig" >>>> + >>>> source "drivers/hv/Kconfig" >>>> source "drivers/xen/Kconfig" >>>> diff --git a/drivers/misc/mic/Kconfig b/drivers/misc/mic/Kconfig >>>> index b6841ba6d922..8f201d019f5a 100644 >>>> --- a/drivers/misc/mic/Kconfig >>>> +++ b/drivers/misc/mic/Kconfig >>>> @@ -133,8 +133,4 @@ config VOP >>>> OS and tools for MIC to use with this driver are available from >>>> . >>>> -if VOP >>>> -source "drivers/vhost/Kconfig.vringh" >>>> -endif >>>> - >>>> endmenu >>>> diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig >>>> index e74e2bb61236..9db0570c5beb 100644 >>>> --- a/drivers/net/caif/Kconfig >>>> +++ b/drivers/net/caif/Kconfig >>>> @@ -58,8 +58,4 @@ config CAIF_VIRTIO >>>> ---help--- >>>> The CAIF driver for CAIF over Virtio. >>>> -if CAIF_VIRTIO >>>> -source "drivers/vhost/Kconfig.vringh" >>>> -endif >>>> - >>>> endif # CAIF_DRIVERS >>>> diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig >>>> index 3d03ccbd1adc..4aef10a54cd1 100644 >>>> --- a/drivers/vhost/Kconfig >>>> +++ b/drivers/vhost/Kconfig >>>> @@ -1,8 +1,20 @@ >>>> # SPDX-License-Identifier: GPL-2.0-only >>>> +config VHOST_RING >>>> + tristate >>>> + help >>>> + This option is selected by any driver which needs to access >>>> + the host side of a virtio ring. >>>> + >>>> +menuconfig VHOST >>>> + tristate "Host kernel accelerator for virtio (VHOST)" >>>> + help >>>> + This option is selected by any driver which needs to access >>>> + the core of vhost. >>>> +if VHOST >>>> + >>> The description here is wrong, isn't it? >>> VHOST and VHOST_RING are no longer selected, right? >> >> For VHOST not currently. > Can we just bring it back and select it? Right, so if bring it back, we don't even need the stub. How about something like attached? Thanks > >> For VHOST_RING, it was selected by CAIF, VOP and VDPASIM. >> >> Thanks >> >> >>> >>>> config VHOST_NET >>>> tristate "Host kernel accelerator for virtio net" >>>> depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) >>>> - select VHOST >>>> ---help--- >>>> This kernel module can be loaded in host kernel to accelerate >>>> guest networking with virtio_net. Not to be confused with virtio_net >>>> @@ -14,7 +26,6 @@ config VHOST_NET >>>> config VHOST_SCSI >>>> tristate "VHOST_SCSI TCM fabric driver" >>>> depends on TARGET_CORE && EVENTFD >>>> - select VHOST >>>> default n >>>> ---help--- >>>> Say M here to enable the vhost_scsi TCM fabric module >>>> @@ -24,7 +35,6 @@ config VHOST_VSOCK >>>> tristate "vhost virtio-vsock driver" >>>> depends on VSOCKETS && EVENTFD >>>> select VIRTIO_VSOCKETS_COMMON >>>> - select VHOST >>>> default n >>>> ---help--- >>>> This kernel module can be loaded in the host kernel to provide AF_VSOCK >>>> @@ -34,12 +44,6 @@ config VHOST_VSOCK >>>> To compile this driver as a module, choose M here: the module will be called >>>> vhost_vsock. >>>> -config VHOST >>>> - tristate >>>> - ---help--- >>>> - This option is selected by any driver which needs to access >>>> - the core of vhost. >>>> - >>>> config VHOST_CROSS_ENDIAN_LEGACY >>>> bool "Cross-endian support for vhost" >>>> default n >>>> @@ -54,3 +58,4 @@ config VHOST_CROSS_ENDIAN_LEGACY >>>> adds some overhead, it is disabled by default. >>>> If unsure, say "N". >>>> +endif >>>> diff --git a/drivers/vhost/Kconfig.vringh b/drivers/vhost/Kconfig.vringh >>>> deleted file mode 100644 >>>> index c1fe36a9b8d4..000000000000 >>>> --- a/drivers/vhost/Kconfig.vringh >>>> +++ /dev/null >>>> @@ -1,6 +0,0 @@ >>>> -# SPDX-License-Identifier: GPL-2.0-only >>>> -config VHOST_RING >>>> - tristate >>>> - ---help--- >>>> - This option is selected by any driver which needs to access >>>> - the host side of a virtio ring. >>>> -- >>>> 2.20.1