Re: [PATCH 3/3] vDPA/ifcvf: get_config_size should return dev specific config size

2021-04-15 Thread Jason Wang 



在 2021/4/15 下午4:12, Stefano Garzarella 写道:

On Wed, Apr 14, 2021 at 05:18:32PM +0800, Zhu Lingshan wrote:

get_config_size() should return the size based on the decected
device type.

Signed-off-by: Zhu Lingshan 
---
drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c 
b/drivers/vdpa/ifcvf/ifcvf_main.c

index 9b6a38b798fa..b48b9789b69e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct 
vdpa_device *vdpa_dev)


static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
{
-    return sizeof(struct virtio_net_config);
+    struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+    size_t size;
+
+    if (vf->dev_type == VIRTIO_ID_NET)
+    size = sizeof(struct virtio_net_config);
+
+    if (vf->dev_type == VIRTIO_ID_BLOCK)
+    size = sizeof(struct virtio_blk_config);
+
+    return size;


I'm not familiar with the ifcvf details, but can it happen that the 
device is not block or net?


Should we set `size` to 0 by default to handle this case or are we 
sure it's one of the two?


Maybe we should add a comment or a warning message in this case, to 
prevent some analysis tool or compiler from worrying that `size` might 
be uninitialized.


I was thinking something like this:

switch(vf->dev_type) {
case VIRTIO_ID_NET:
    size = sizeof(struct virtio_net_config);
    break;
case VIRTIO_ID_BLOCK:
    size = sizeof(struct virtio_blk_config);
    break;
default:
    /* or WARN(1, "") if dev_warn() not apply */
    dev_warn(... , "virtio ID [0x%x] not supported\n")
    size = 0;

}



Yes, I agree.

Thanks



Thanks,
Stefano

Re: [PATCH 3/3] vDPA/ifcvf: get_config_size should return dev specific config size

2021-04-15 Thread Stefano Garzarella 

On Wed, Apr 14, 2021 at 05:18:32PM +0800, Zhu Lingshan wrote:

get_config_size() should return the size based on the decected
device type.

Signed-off-by: Zhu Lingshan 
---
drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 9b6a38b798fa..b48b9789b69e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device 
*vdpa_dev)

static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
{
-   return sizeof(struct virtio_net_config);
+   struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+   size_t size;
+
+   if (vf->dev_type == VIRTIO_ID_NET)
+   size = sizeof(struct virtio_net_config);
+
+   if (vf->dev_type == VIRTIO_ID_BLOCK)
+   size = sizeof(struct virtio_blk_config);
+
+   return size;


I'm not familiar with the ifcvf details, but can it happen that the 
device is not block or net?


Should we set `size` to 0 by default to handle this case or are we sure 
it's one of the two?


Maybe we should add a comment or a warning message in this case, to 
prevent some analysis tool or compiler from worrying that `size` might 
be uninitialized.


I was thinking something like this:

switch(vf->dev_type) {
case VIRTIO_ID_NET:
size = sizeof(struct virtio_net_config);
break;
case VIRTIO_ID_BLOCK:
size = sizeof(struct virtio_blk_config);
break;
default:
/* or WARN(1, "") if dev_warn() not apply */
dev_warn(... , "virtio ID [0x%x] not supported\n")
size = 0;

}

Thanks,
Stefano

Re: [PATCH 3/3] vDPA/ifcvf: get_config_size should return dev specific config size

2021-04-14 Thread Jason Wang 



在 2021/4/14 下午5:18, Zhu Lingshan 写道:

get_config_size() should return the size based on the decected
device type.

Signed-off-by: Zhu Lingshan 



Acked-by: Jason Wang 



---
  drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 9b6a38b798fa..b48b9789b69e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device 
*vdpa_dev)
  
  static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)

  {
-   return sizeof(struct virtio_net_config);
+   struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+   size_t size;
+
+   if (vf->dev_type == VIRTIO_ID_NET)
+   size = sizeof(struct virtio_net_config);
+
+   if (vf->dev_type == VIRTIO_ID_BLOCK)
+   size = sizeof(struct virtio_blk_config);
+
+   return size;
  }
  
  static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,

[PATCH 3/3] vDPA/ifcvf: get_config_size should return dev specific config size

2021-04-14 Thread Zhu Lingshan 
get_config_size() should return the size based on the decected
device type.

Signed-off-by: Zhu Lingshan 
---
 drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 9b6a38b798fa..b48b9789b69e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device 
*vdpa_dev)
 
 static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
 {
-   return sizeof(struct virtio_net_config);
+   struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+   size_t size;
+
+   if (vf->dev_type == VIRTIO_ID_NET)
+   size = sizeof(struct virtio_net_config);
+
+   if (vf->dev_type == VIRTIO_ID_BLOCK)
+   size = sizeof(struct virtio_blk_config);
+
+   return size;
 }
 
 static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,
-- 
2.27.0