Re: [PATCH V3 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf

On 6/1/2021 4:50 PM, Jason Wang wrote:

在 2021/6/1 下午2:28, Zhu Lingshan 写道:

quoted

This commit implements doorbell mapping feature for ifcvf.
This feature maps the notify page to userspace, to eliminate
vmexit when kick a vq.

Signed-off-by: Zhu Lingshan <redacted>
---
  drivers/vdpa/ifcvf/ifcvf_main.c | 21 +++++++++++++++++++++
  1 file changed, 21 insertions(+)

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

b/drivers/vdpa/ifcvf/ifcvf_main.c
index ab0ab5cf0f6e..d41db042612c 100644

--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c

@@ -413,6 +413,26 @@ static int ifcvf_vdpa_get_vq_irq(struct 

vdpa_device *vdpa_dev,
      return vf->vring[qid].irq;
  }
  +static struct vdpa_notification_area 
ifcvf_get_vq_notification(struct vdpa_device *vdpa_dev,
+                                   u16 idx)
+{
+    struct ifcvf_adapter *adapter = vdpa_to_adapter(vdpa_dev);
+    struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+    struct pci_dev *pdev = adapter->pdev;
+    struct vdpa_notification_area area;
+
+    area.addr = vf->vring[idx].notify_pa;
+    if (!vf->notify_off_multiplier)
+        area.size = PAGE_SIZE;
+    else
+        area.size = vf->notify_off_multiplier;
+
+    if (area.addr % PAGE_SIZE)
+        IFCVF_DBG(pdev, "vq %u doorbell address is not PAGE_SIZE 
aligned\n", idx);

I don't see the reason to keep this, or get_notification is not the 
proper place to do this kind of warning.

Thanks

some customers have ever complained have troubles to enable such 
features with their IP,
I think this can help them debug.

Thanks

quoted

+
+    return area;
+}
+
  /*
   * IFCVF currently does't have on-chip IOMMU, so not
   * implemented set_map()/dma_map()/dma_unmap()

@@ -440,6 +460,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops = {

      .get_config    = ifcvf_vdpa_get_config,
      .set_config    = ifcvf_vdpa_set_config,
      .set_config_cb  = ifcvf_vdpa_set_config_cb,
+    .get_vq_notification = ifcvf_get_vq_notification,
  };
    static int ifcvf_probe(struct pci_dev *pdev, const struct 
pci_device_id *id)