Re: [RFC PATCH v6 2/4] iommu/vt-d: don's issue devTLB flush request when device is disconnected

[Ethan Zhao]

On 12/24/2023 6:32 PM, Lukas Wunner wrote:
> On Sun, Dec 24, 2023 at 12:06:55AM -0500, Ethan Zhao wrote:
> > --- a/drivers/iommu/intel/pasid.c
> > +++ b/drivers/iommu/intel/pasid.c
> > @@ -481,6 +481,9 @@ devtlb_invalidation_with_pasid(struct intel_iommu *iommu,
> >   	if (!info || !info->ats_enabled)
> >   		return;
> >   
> > +	if (pci_dev_is_disconnected(to_pci_dev(dev)))
> > +		return;
> > +
> >   	sid = info->bus << 8 | info->devfn;
> >   	qdep = info->ats_qdep;
> >   	pfsid = info->pfsid;
> Do you even need this or is patch [4/4] sufficient?
> Is there a benefit to the hunk above on top of patch [4/4]?

Need this,  I don't want to access config space here, check the

flag here is enough, but patch [4/] needs to know if the device

 is gone by reading device vendor info.


Thanks,

Ethan


> Thanks,
>
> Lukas