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Xuan Zhuo

2023-Oct-11 09:27 UTC

[PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable

virtqueue_set_dma_premapped() adds a new parameter to disable the
virtqueue premapped mode.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c     |  2 +-
 drivers/virtio/virtio_ring.c | 11 ++++++++---
 include/linux/virtio.h       |  2 +-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index fe7f314d65c9..6b5f47ebf9b2 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -737,7 +737,7 @@ static void virtnet_rq_set_premapped(struct virtnet_info
*vi)
 		return;
 
 	for (i = 0; i < vi->max_queue_pairs; i++) {
-		if (virtqueue_set_dma_premapped(vi->rq[i].vq))
+		if (virtqueue_set_dma_premapped(vi->rq[i].vq, true))
 			continue;
 
 		vi->rq[i].do_dma = true;
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 51d8f3299c10..b3ded56722f4 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2784,7 +2784,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize);
  * 0: success.
  * -EINVAL: vring does not use the dma api, so we can not enable premapped
mode.
  */
-int virtqueue_set_dma_premapped(struct virtqueue *_vq)
+int virtqueue_set_dma_premapped(struct virtqueue *_vq, bool mode)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);
 	u32 num;
@@ -2803,8 +2803,13 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
 		return -EINVAL;
 	}
 
-	vq->premapped = true;
-	vq->do_unmap = false;
+	if (mode) {
+		vq->premapped = true;
+		vq->do_unmap = false;
+	} else {
+		vq->premapped = false;
+		vq->do_unmap = vq->use_dma_api;
+	}
 
 	END_USE(vq);
 
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 4cc614a38376..1cf7b004348b 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -81,7 +81,7 @@ bool virtqueue_enable_cb(struct virtqueue *vq);
 
 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
 
-int virtqueue_set_dma_premapped(struct virtqueue *_vq);
+int virtqueue_set_dma_premapped(struct virtqueue *_vq, bool mode);
 
 bool virtqueue_poll(struct virtqueue *vq, unsigned);
 
-- 
2.32.0.3.g01195cf9f

kernel test robot

2023-Oct-11 14:13 UTC

head link

[PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable

Hi Xuan,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.6-rc5 next-20231011]
[cannot apply to mst-vhost/linux-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:   
https://github.com/intel-lab-lkp/linux/commits/Xuan-Zhuo/virtio_ring-virtqueue_set_dma_premapped-support-disable/20231011-180709
base:   linus/master
patch link:   
https://lore.kernel.org/r/20231011092728.105904-2-xuanzhuo%40linux.alibaba.com
patch subject: [PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped
support disable
config: m68k-allyesconfig
(https://download.01.org/0day-ci/archive/20231011/202310112204.h03TUDpH-lkp at
intel.com/config)
compiler: m68k-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build):
(https://download.01.org/0day-ci/archive/20231011/202310112204.h03TUDpH-lkp at
intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310112204.h03TUDpH-lkp at
intel.com/

All warnings (new ones prefixed by >>):
>> drivers/virtio/virtio_ring.c:2788: warning: Function parameter or
member 'mode' not described in 'virtqueue_set_dma_premapped'

vim +2788 drivers/virtio/virtio_ring.c

c790e8e1817f1a Xuan Zhuo 2022-08-01  2765  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2766  /**
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2767   * virtqueue_set_dma_premapped - set
the vring premapped mode
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2768   * @_vq: the struct virtqueue
we're talking about.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2769   *
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2770   * Enable the premapped mode of the
vq.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2771   *
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2772   * The vring in premapped mode does
not do dma internally, so the driver must
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2773   * do dma mapping in advance. The
driver must pass the dma_address through
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2774   * dma_address of scatterlist. When
the driver got a used buffer from
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2775   * the vring, it has to unmap the dma
address.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2776   *
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2777   * This function must be called
immediately after creating the vq, or after vq
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2778   * reset, and before adding any
buffers to it.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2779   *
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2780   * Caller must ensure we don't
call this with other virtqueue operations
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2781   * at the same time (except where
noted).
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2782   *
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2783   * Returns zero or a negative error.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2784   * 0: success.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2785   * -EINVAL: vring does not use the
dma api, so we can not enable premapped mode.
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2786   */
f8d1a236ad114f Xuan Zhuo 2023-10-11  2787  int
virtqueue_set_dma_premapped(struct virtqueue *_vq, bool mode)
8daafe9ebbd21a Xuan Zhuo 2023-08-10 @2788  {
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2789  	struct vring_virtqueue *vq =
to_vvq(_vq);
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2790  	u32 num;
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2791  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2792  	START_USE(vq);
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2793  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2794  	num = vq->packed_ring ?
vq->packed.vring.num : vq->split.vring.num;
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2795  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2796  	if (num != vq->vq.num_free) {
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2797  		END_USE(vq);
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2798  		return -EINVAL;
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2799  	}
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2800  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2801  	if (!vq->use_dma_api) {
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2802  		END_USE(vq);
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2803  		return -EINVAL;
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2804  	}
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2805  
f8d1a236ad114f Xuan Zhuo 2023-10-11  2806  	if (mode) {
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2807  		vq->premapped = true;
b319940f83c21b Xuan Zhuo 2023-08-10  2808  		vq->do_unmap = false;
f8d1a236ad114f Xuan Zhuo 2023-10-11  2809  	} else {
f8d1a236ad114f Xuan Zhuo 2023-10-11  2810  		vq->premapped = false;
f8d1a236ad114f Xuan Zhuo 2023-10-11  2811  		vq->do_unmap =
vq->use_dma_api;
f8d1a236ad114f Xuan Zhuo 2023-10-11  2812  	}
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2813  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2814  	END_USE(vq);
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2815  
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2816  	return 0;
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2817  }
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2818 
EXPORT_SYMBOL_GPL(virtqueue_set_dma_premapped);
8daafe9ebbd21a Xuan Zhuo 2023-08-10  2819  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Michael S. Tsirkin

2023-Oct-12 09:15 UTC

head link

[PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable

On Wed, Oct 11, 2023 at 05:27:07PM +0800, Xuan Zhuo
wrote:> virtqueue_set_dma_premapped() adds a new parameter to disable the
> virtqueue premapped mode.
> 
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> ---
>  drivers/net/virtio_net.c     |  2 +-
>  drivers/virtio/virtio_ring.c | 11 ++++++++---
>  include/linux/virtio.h       |  2 +-
>  3 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index fe7f314d65c9..6b5f47ebf9b2 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -737,7 +737,7 @@ static void virtnet_rq_set_premapped(struct
virtnet_info *vi)
>  		return;
>  
>  	for (i = 0; i < vi->max_queue_pairs; i++) {
> -		if (virtqueue_set_dma_premapped(vi->rq[i].vq))
> +		if (virtqueue_set_dma_premapped(vi->rq[i].vq, true))
>  			continue;
>  
>  		vi->rq[i].do_dma = true;
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 51d8f3299c10..b3ded56722f4 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -2784,7 +2784,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize);
>   * 0: success.
>   * -EINVAL: vring does not use the dma api, so we can not enable premapped
mode.
>   */
> -int virtqueue_set_dma_premapped(struct virtqueue *_vq)
> +int virtqueue_set_dma_premapped(struct virtqueue *_vq, bool mode)
>  {
>  	struct vring_virtqueue *vq = to_vvq(_vq);
>  	u32 num;
> @@ -2803,8 +2803,13 @@ int virtqueue_set_dma_premapped(struct virtqueue
*_vq)
>  		return -EINVAL;
>  	}
>  
> -	vq->premapped = true;
> -	vq->do_unmap = false;
> +	if (mode) {
> +		vq->premapped = true;
> +		vq->do_unmap = false;
> +	} else {
> +		vq->premapped = false;
> +		vq->do_unmap = vq->use_dma_api;
> +	}
>  
>  	END_USE(vq);
>  
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index 4cc614a38376..1cf7b004348b 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -81,7 +81,7 @@ bool virtqueue_enable_cb(struct virtqueue *vq);
>  
>  unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
>  
> -int virtqueue_set_dma_premapped(struct virtqueue *_vq);
> +int virtqueue_set_dma_premapped(struct virtqueue *_vq, bool mode);
>  
>  bool virtqueue_poll(struct virtqueue *vq, unsigned);
Wait a sec I thought we never change premapped. If you make this
dynamic don't you need a bunch of locking?
Or maybe queue is empty when you change this?
If yes pls add a bunch of BUG_ON checks to make sure this is not misused.

> -- 
> 2.32.0.3.g01195cf9f

Linux Virtualization - Oct 2023 - [PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable

[PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable

[PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable

[PATCH vhost 01/22] virtio_ring: virtqueue_set_dma_premapped support disable