> From: Jan Beulich
> Sent: Wednesday, June 9, 2021 5:29 PM
>
> While no longer an immediate problem with flushes no longer timing out,
> errors (if any) get properly reported by iommu_flush_iotlb_{dsi,psi}().
> Overwriting such an error with, perhaps, a success indicator received
> from another IOMMU will misguide callers. Record the first error, but
> don't bail from the loop (such that further necessary invalidation gets
> carried out on a best effort basis).
>
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
>
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -643,7 +643,7 @@ static int __must_check iommu_flush_iotl
> struct vtd_iommu *iommu;
> bool_t flush_dev_iotlb;
> int iommu_domid;
> - int rc = 0;
> + int ret = 0;
>
> /*
> * No need pcideves_lock here because we have flush
> @@ -651,6 +651,8 @@ static int __must_check iommu_flush_iotl
> */
> for_each_drhd_unit ( drhd )
> {
> + int rc;
> +
> iommu = drhd->iommu;
>
> if ( !test_bit(iommu->index, &hd->arch.vtd.iommu_bitmap) )
> @@ -673,13 +675,12 @@ static int __must_check iommu_flush_iotl
> flush_dev_iotlb);
>
> if ( rc > 0 )
> - {
> iommu_flush_write_buffer(iommu);
> - rc = 0;
> - }
> + else if ( !ret )
> + ret = rc;
> }
>
> - return rc;
> + return ret;
> }
>
> static int __must_check iommu_flush_iotlb_pages(struct domain *d,
>
