? 2021/4/28 ??6:00, Zhu, Lingshan ??:>
>
> On 4/28/2021 4:39 PM, Jason Wang wrote:
>>
>> ? 2021/4/28 ??4:21, Zhu Lingshan ??:
>>> This commit records virtio notify base addr to implemente
>>> doorbell mapping feature
>>>
>>> Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com>
>>> ---
>>> ? 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.
Thanks
>
> Thanks
> Zhu Lingshan
>>
>> Thanks
>>
>> [1]
>> https://lore.kernel.org/virtualization/20210415073147.19331-5-jasowang
at redhat.com/T/
>>
>>
>>> 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 {
>>
>