On 4/28/2021 6:09 PM, Jason Wang wrote:

在 2021/4/28 下午6:00, Zhu, Lingshan 写道:

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On 4/28/2021 4:39 PM, Jason Wang wrote:

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在 2021/4/28 下午4:21, Zhu Lingshan 写道:

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This commit records virtio notify base addr to implemente
doorbell mapping feature

Signed-off-by: Zhu Lingshan <redacted>
---
  drivers/vdpa/ifcvf/ifcvf_base.c | 1 +
  drivers/vdpa/ifcvf/ifcvf_base.h | 1 +
  2 files changed, 2 insertions(+)

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

b/drivers/vdpa/ifcvf/ifcvf_base.c
index 1a661ab45af5..cc61a5bfc5b1 100644

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

@@ -133,6 +133,7 @@ int ifcvf_init_hw(struct ifcvf_hw *hw, struct 

pci_dev *pdev)
&hw->notify_off_multiplier);
              hw->notify_bar = cap.bar;
              hw->notify_base = get_cap_addr(hw, &cap);
+            hw->notify_pa = pci_resource_start(pdev, cap.bar) + 
cap.offset;

To be more generic and avoid future changes, let's use the math 
defined in the virtio spec.

You may refer how it is implemented in virtio_pci vdpa driver[1].

Are you suggesting every vq keep its own notify_pa? In this case, we 
still need to record notify_pa in hw when init_hw, then initialize 
vq->notify_pa accrediting to hw->notify_pa.

I meant you need to follow how virtio spec did to calculate the 
doorbell address per vq:

        cap.offset + queue_notify_off * notify_off_multiplier

Obviously, you ignore queue_notify_off and notify_off_multiplier here. 
This may bring troubles for the existing device IFCVF and future devices.

If I understand correctly, this device can be probed by virtio-pci 
driver which use the above math. There's no reason for using ad-hoc hack.

sure, when talking about initialize vq->notify_pa, I mean calculate with 
with notify_base and multiplier, V2 will include this.

Thanks,
Zhu Lingshan

Thanks

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Thanks
Zhu Lingshan

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Thanks

[1] 
https://lore.kernel.org/virtualization/20210415073147.19331-5-jasowang@redhat.com/T/ (local)

quoted

IFCVF_DBG(pdev, "hw->notify_base = %p\n",
                    hw->notify_base);
              break;

diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h 

b/drivers/vdpa/ifcvf/ifcvf_base.h
index 0111bfdeb342..bcca7c1669dd 100644

--- a/drivers/vdpa/ifcvf/ifcvf_base.h
+++ b/drivers/vdpa/ifcvf/ifcvf_base.h

@@ -98,6 +98,7 @@ struct ifcvf_hw {

      char config_msix_name[256];
      struct vdpa_callback config_cb;
      unsigned int config_irq;
+    phys_addr_t  notify_pa;
  };
    struct ifcvf_adapter {