Re: [PATCH v2 9/9] iommu/vt-d: Store guest PASID during bind

[Auger Eric <eric.auger@redhat.com>]

Hi Jacob,
On 8/22/20 6:35 AM, Jacob Pan wrote:
> IOASID core maintains the guest-host mapping in the form of SPID and
> IOASID. This patch assigns the guest PASID (if valid) as SPID while
> binding guest page table with a host PASID. This mapping will be used
> for lookup and notifications.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>  drivers/iommu/intel/svm.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index d8a5efa75095..4c958b1aec4c 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -406,6 +406,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
>  		if (data->flags & IOMMU_SVA_GPASID_VAL) {
>  			svm->gpasid = data->gpasid;
>  			svm->flags |= SVM_FLAG_GUEST_PASID;
> +			ioasid_attach_spid(data->hpasid, data->gpasid);
don't you want to handle the returned value?
>  		}
>  		svm->iommu = iommu;
>  		/*
> @@ -517,6 +518,7 @@ int intel_svm_unbind_gpasid(struct device *dev, int pasid)
>  				ioasid_attach_data(pasid, NULL);
>  				ioasid_notify(pasid, IOASID_UNBIND,
>  					IOASID_NOTIFY_SET);
> +				ioasid_attach_spid(pasid, INVALID_IOASID);
So this answers my previous question ;-) but won't it enter the if
(!ioasid_data) path and fail to reset the spid?

Eric
>  				kfree(svm);
>  			}
>  		}
>