Subject: Re: [PATCH] vhost-scsi: Depend on NET for memcpy_fromiovec

From: Asias He <[email-masked]>
Date: Thu, 16 May 2013 09:48:44 +0800

On Wed, May 15, 2013 at 03:37:30PM -0700, Nicholas A. Bellinger wrote:
> On Wed, 2013-05-15 at 14:47 +0930, Rusty Russell wrote:
> > Asias He <[email-masked]> writes:
> > > scsi.c includes vhost.c which uses memcpy_fromiovec.
> > >
> > > This patch fixes this build failure.
> > >
> > >    From Randy Dunlap:
> > >    '''
> > >    on x86_64:
> > >
> > >    ERROR: "memcpy_fromiovec" [drivers/vhost/vhost_scsi.ko] undefined!
> > >
> > >    It needs to depend on NET since net/core/ provides that function.
> > >    '''
> > 
> > Proper fix please.
> > 
> > Though I can't see why you thought this was a good idea.  Nonetheless, I
> > shan't highlight why: I have far too much respect for your intellects
> > and abilities.
> > 
> > No, don't thank me!
> 
> Hi Rusty & Asias,
> 
> I assume you mean something like the following patch to allow kbuild to
> work when VHOST_NET + VHOST_SCSI are both enabled and sharing vhost.o,
> yes..?
> 
> Also included is dropping the now unnecessary vhost.c include, and
> allowing vhost_work_flush() to be accessed externally as scsi.c
> currently requires.
> 
> MST, care to pick this up..?
> 
> --nab

Couple of days ago, I have separated the vhost.ko. 

'vhost: Make vhost a separate module'

http://www.spinics.net/lists/kvm/msg90825.html

MST wanted to queue it up for 3.11. 

> 
> diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
> index 8b9226d..016387f 100644
> --- a/drivers/vhost/Kconfig
> +++ b/drivers/vhost/Kconfig
> @@ -1,3 +1,6 @@
> +config VHOST
> +       tristate
> +
>  config VHOST_NET
>         tristate "Host kernel accelerator for virtio net"
>         depends on NET && EVENTFD && (TUN || !TUN) && (MACVTAP || !MACVTAP)
> @@ -12,7 +15,7 @@ config VHOST_NET
>  
>  config VHOST_SCSI
>         tristate "VHOST_SCSI TCM fabric driver"
> -       depends on TARGET_CORE && EVENTFD && m
> +       depends on NET && EVENTFD && TARGET_CORE
>         select VHOST_RING
>         default n
>         ---help---
> diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
> index 654e9afb..e5b5f0b 100644
> --- a/drivers/vhost/Makefile
> +++ b/drivers/vhost/Makefile
> @@ -1,7 +1,9 @@
> +obj-$(CONFIG_VHOST) += vhost.o
> +
>  obj-$(CONFIG_VHOST_NET) += vhost_net.o
> -vhost_net-y := vhost.o net.o
> +vhost_net-objs := net.o
>  
>  obj-$(CONFIG_VHOST_SCSI) += vhost_scsi.o
> -vhost_scsi-y := scsi.o
> +vhost_scsi-objs := scsi.o
>  
>  obj-$(CONFIG_VHOST_RING) += vringh.o
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 7014202..b5836a2 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -49,7 +49,6 @@
>  #include <linux/llist.h>
>  #include <linux/bitmap.h>
>  
> -#include "vhost.c"
>  #include "vhost.h"
>  
>  #define TCM_VHOST_VERSION  "v0.1"
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index beee7f5..8cd1562 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -123,7 +123,7 @@ static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work,
>         return left <= 0;
>  }
>  
> -static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
> +void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
>  {
>         unsigned seq;
>         int flushing;
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index a7ad635..50ee396 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -44,6 +44,7 @@ void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
>                      unsigned long mask, struct vhost_dev *dev);
>  int vhost_poll_start(struct vhost_poll *poll, struct file *file);
>  void vhost_poll_stop(struct vhost_poll *poll);
> +void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
>  void vhost_poll_flush(struct vhost_poll *poll);
>  void vhost_poll_queue(struct vhost_poll *poll);
> 
> 

-- 
Asias