From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH V9 1/9] vhost: refine vhost and vringh kconfig Date: Wed, 1 Apr 2020 10:27:24 -0400 Message-ID: <20200401102631-mutt-send-email-mst@kernel.org> References: <20200326140125.19794-1-jasowang@redhat.com> <20200326140125.19794-2-jasowang@redhat.com> <41ee1f6a-3124-d44b-bf34-0f26604f9514@redhat.com> <4726da4c-11ec-3b6e-1218-6d6d365d5038@de.ibm.com> <39b96e3a-9f4e-6e1d-e988-8c4bcfb55879@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Jason Wang Cc: Christian Borntraeger , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, jgg@mellanox.com, maxime.coquelin@redhat.com, cunming.liang@intel.com, zhihong.wang@intel.com, rob.miller@broadcom.com, xiao.w.wang@intel.com, lingshan.zhu@intel.com, eperezma@redhat.com, lulu@redhat.com, parav@mellanox.com, kevin.tian@intel.com, stefanha@redhat.com, rdunlap@infradead.org, hch@infradead.org, aadam@redhat.com, jiri@mellanox.com, shahafs@mellanox.com, hanand@xilinx.com, mhabets@solarflare.com, gdawar@xilinx.com, saugatm@xilinx.com, vmireyno@marvell.com, zhangweining@ruijie.com.cn List-Id: virtualization@lists.linuxfoundation.org On Wed, Apr 01, 2020 at 10:13:29PM +0800, Jason Wang wrote: > > On 2020/4/1 下午9:02, Christian Borntraeger wrote: > > > > On 01.04.20 14:56, Christian Borntraeger wrote: > > > On 01.04.20 14:50, Jason Wang wrote: > > > > On 2020/4/1 下午7:21, Christian Borntraeger wrote: > > > > > On 26.03.20 15:01, 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. > > > > > FWIW, this now results in vhost not being build with defconfig kernels (in todays > > > > > linux-next). > > > > > > > > > Hi Christian: > > > > > > > > Did you meet it even with this commit https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=a4be40cbcedba9b5b714f3c95182e8a45176e42d? > > > I simply used linux-next. The defconfig does NOT contain CONFIG_VHOST and therefore CONFIG_VHOST_NET and friends > > > can not be selected. > > > > > > $ git checkout next-20200401 > > > $ make defconfig > > > HOSTCC scripts/basic/fixdep > > > HOSTCC scripts/kconfig/conf.o > > > HOSTCC scripts/kconfig/confdata.o > > > HOSTCC scripts/kconfig/expr.o > > > LEX scripts/kconfig/lexer.lex.c > > > YACC scripts/kconfig/parser.tab.[ch] > > > HOSTCC scripts/kconfig/lexer.lex.o > > > HOSTCC scripts/kconfig/parser.tab.o > > > HOSTCC scripts/kconfig/preprocess.o > > > HOSTCC scripts/kconfig/symbol.o > > > HOSTCC scripts/kconfig/util.o > > > HOSTLD scripts/kconfig/conf > > > *** Default configuration is based on 'x86_64_defconfig' > > > # > > > # configuration written to .config > > > # > > > > > > $ grep VHOST .config > > > # CONFIG_VHOST is not set > > > > > > > If yes, what's your build config looks like? > > > > > > > > Thanks > > This was x86. Not sure if that did work before. > > On s390 this is definitely a regression as the defconfig files > > for s390 do select VHOST_NET > > > > grep VHOST arch/s390/configs/* > > arch/s390/configs/debug_defconfig:CONFIG_VHOST_NET=m > > arch/s390/configs/debug_defconfig:CONFIG_VHOST_VSOCK=m > > arch/s390/configs/defconfig:CONFIG_VHOST_NET=m > > arch/s390/configs/defconfig:CONFIG_VHOST_VSOCK=m > > > > and this worked with 5.6, but does not work with next. Just adding > > CONFIG_VHOST=m to the defconfig solves the issue, something like > > > Right, I think we probably need > > 1) add CONFIG_VHOST=m to all defconfigs that enables > CONFIG_VHOST_NET/VSOCK/SCSI. > > or > > 2) don't use menuconfig for CONFIG_VHOST, let NET/SCSI/VDPA just select it. > > Thanks OK I tried this: diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index 2523a1d4290a..a314b900d479 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -19,11 +19,10 @@ menuconfig VHOST This option is selected by any driver which needs to access the core of vhost. -if VHOST - 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 @@ -35,6 +34,7 @@ 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 @@ -44,6 +44,7 @@ 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 @@ -57,6 +58,7 @@ config VHOST_VDPA tristate "Vhost driver for vDPA-based backend" depends on EVENTFD select VDPA + select VHOST help This kernel module can be loaded in host kernel to accelerate guest virtio devices with the vDPA-based backends. @@ -78,5 +80,3 @@ config VHOST_CROSS_ENDIAN_LEGACY adds some overhead, it is disabled by default. If unsure, say "N". - -endif But now CONFIG_VHOST is always "y", never "m". Which I think will make it a built-in. Didn't figure out why yet. -- MST