Re: [PATCH] virtio/test: fix up after IOTLB changes

[Jason Wang <jasowang@redhat.com>]

On 2020/4/2 下午8:53, Michael S. Tsirkin wrote:
> On Thu, Apr 02, 2020 at 12:01:56PM +0800, Jason Wang wrote:
>> On 2020/4/2 上午12:51, Michael S. Tsirkin wrote:
>>> Allow building vringh without IOTLB (that's the case for userspace
>>> builds, will be useful for CAIF/VOD down the road too).
>>> Update for API tweaks.
>>> Don't include vringh with kernel builds.
>>
>> I'm not quite sure we need this.
>>
>> E.g the userspace accessor is not used by CAIF/VOP.
> Well any exported symbols are always compiled in, right?
> So we can save some kernel memory by not building unused stuff ...


Yes, just want to mention that the there's no user for userspace 
accessors now.


>
>
>>> Cc: Jason Wang <jasowang@redhat.com>
>>> Cc: Eugenio Pérez <eperezma@redhat.com>
>>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>>> ---
>>>    drivers/vhost/test.c   | 4 ++--
>>>    drivers/vhost/vringh.c | 5 +++++
>>>    include/linux/vringh.h | 2 ++
>>>    tools/virtio/Makefile  | 3 ++-
>>>    4 files changed, 11 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
>>> index 394e2e5c772d..9a3a09005e03 100644
>>> --- a/drivers/vhost/test.c
>>> +++ b/drivers/vhost/test.c
>>> @@ -120,7 +120,7 @@ static int vhost_test_open(struct inode *inode, struct file *f)
>>>    	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
>>>    	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
>>>    	vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
>>> -		       VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT);
>>> +		       VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, NULL);
>>>    	f->private_data = n;
>>> @@ -225,7 +225,7 @@ static long vhost_test_reset_owner(struct vhost_test *n)
>>>    {
>>>    	void *priv = NULL;
>>>    	long err;
>>> -	struct vhost_umem *umem;
>>> +	struct vhost_iotlb *umem;
>>>    	mutex_lock(&n->dev.mutex);
>>>    	err = vhost_dev_check_owner(&n->dev);
>>> diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
>>> index ee0491f579ac..878e565dfffe 100644
>>> --- a/drivers/vhost/vringh.c
>>> +++ b/drivers/vhost/vringh.c
>>> @@ -13,9 +13,11 @@
>>>    #include <linux/uaccess.h>
>>>    #include <linux/slab.h>
>>>    #include <linux/export.h>
>>> +#ifdef VHOST_IOTLB
>>
>> Kbuild bot reports build issues with this.
>>
>> It looks to me we should use #if IS_ENABLED(CONFIG_VHOST_IOTLB) here and
>> following checks.
>>
>> Thanks
>>
> In fact IS_REACHEABLE is probably the right thing to do.


Yes.

Thanks


>
>
>>>    #include <linux/bvec.h>
>>>    #include <linux/highmem.h>
>>>    #include <linux/vhost_iotlb.h>
>>> +#endif
>>>    #include <uapi/linux/virtio_config.h>
>>>    static __printf(1,2) __cold void vringh_bad(const char *fmt, ...)
>>> @@ -1059,6 +1061,8 @@ int vringh_need_notify_kern(struct vringh *vrh)
>>>    }
>>>    EXPORT_SYMBOL(vringh_need_notify_kern);
>>> +#ifdef VHOST_IOTLB
>>> +
>>>    static int iotlb_translate(const struct vringh *vrh,
>>>    			   u64 addr, u64 len, struct bio_vec iov[],
>>>    			   int iov_size, u32 perm)
>>> @@ -1416,5 +1420,6 @@ int vringh_need_notify_iotlb(struct vringh *vrh)
>>>    }
>>>    EXPORT_SYMBOL(vringh_need_notify_iotlb);
>>> +#endif
>>>    MODULE_LICENSE("GPL");
>>> diff --git a/include/linux/vringh.h b/include/linux/vringh.h
>>> index bd0503ca6f8f..ebff121c0b02 100644
>>> --- a/include/linux/vringh.h
>>> +++ b/include/linux/vringh.h
>>> @@ -14,8 +14,10 @@
>>>    #include <linux/virtio_byteorder.h>
>>>    #include <linux/uio.h>
>>>    #include <linux/slab.h>
>>> +#ifdef VHOST_IOTLB
>>>    #include <linux/dma-direction.h>
>>>    #include <linux/vhost_iotlb.h>
>>> +#endif
>>>    #include <asm/barrier.h>
>>>    /* virtio_ring with information needed for host access. */
>>> diff --git a/tools/virtio/Makefile b/tools/virtio/Makefile
>>> index f33f32f1d208..d3f152f4660b 100644
>>> --- a/tools/virtio/Makefile
>>> +++ b/tools/virtio/Makefile
>>> @@ -22,7 +22,8 @@ OOT_CONFIGS=\
>>>    	CONFIG_VHOST=m \
>>>    	CONFIG_VHOST_NET=n \
>>>    	CONFIG_VHOST_SCSI=n \
>>> -	CONFIG_VHOST_VSOCK=n
>>> +	CONFIG_VHOST_VSOCK=n \
>>> +	CONFIG_VHOST_RING=n
>>>    OOT_BUILD=KCFLAGS="-I "${OOT_VHOST} ${MAKE} -C ${OOT_KSRC} V=${V}
>>>    oot-build:
>>>    	echo "UNSUPPORTED! Don't use the resulting modules in production!"