Re: [PATCH 1/2] vDPA/ifcvf: record virtio notify base

[Zhu, Lingshan]

On 4/28/2021 4:39 PM, Jason Wang wrote:
> 在 2021/4/28 下午4:21, Zhu Lingshan 写道:
> > This commit records virtio notify base addr to implemente
> > doorbell mapping feature
> >
> > Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
> > ---
> >   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.

Thanks
Zhu Lingshan
> Thanks
>
> [1] 
> https://lore.kernel.org/virtualization/20210415073147.19331-5-jasowang@xxxxxxxxxx/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 {