> From: Jan Beulich <jbeul...@suse.com>
> Sent: Friday, November 12, 2021 5:48 PM
>
> This logic will want invoking from elsewhere.
>
> 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
> @@ -157,6 +157,51 @@ static void cleanup_domid_map(struct dom
> }
> }
>
> +static bool any_pdev_behind_iommu(const struct domain *d,
> + const struct pci_dev *exclude,
> + const struct vtd_iommu *iommu)
> +{
> + const struct pci_dev *pdev;
> +
> + for_each_pdev ( d, pdev )
> + {
> + const struct acpi_drhd_unit *drhd;
> +
> + if ( pdev == exclude )
> + continue;
> +
> + drhd = acpi_find_matched_drhd_unit(pdev);
> + if ( drhd && drhd->iommu == iommu )
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/*
> + * If no other devices under the same iommu owned by this domain,
> + * clear iommu in iommu_bitmap and clear domain_id in domid_bitmap.
> + */
> +static void check_cleanup_domid_map(struct domain *d,
> + const struct pci_dev *exclude,
> + struct vtd_iommu *iommu)
> +{
> + bool found = any_pdev_behind_iommu(d, exclude, iommu);
> +
> + /*
> + * Hidden devices are associated with DomXEN but usable by the
> hardware
> + * domain. Hence they need considering here as well.
> + */
> + if ( !found && is_hardware_domain(d) )
> + found = any_pdev_behind_iommu(dom_xen, exclude, iommu);
> +
> + if ( !found )
> + {
> + clear_bit(iommu->index, dom_iommu(d)->arch.vtd.iommu_bitmap);
> + cleanup_domid_map(d, iommu);
> + }
> +}
> +
> static void sync_cache(const void *addr, unsigned int size)
> {
> static unsigned long clflush_size = 0;
> @@ -1675,27 +1720,6 @@ int domain_context_unmap_one(
> return rc;
> }
>
> -static bool any_pdev_behind_iommu(const struct domain *d,
> - const struct pci_dev *exclude,
> - const struct vtd_iommu *iommu)
> -{
> - const struct pci_dev *pdev;
> -
> - for_each_pdev ( d, pdev )
> - {
> - const struct acpi_drhd_unit *drhd;
> -
> - if ( pdev == exclude )
> - continue;
> -
> - drhd = acpi_find_matched_drhd_unit(pdev);
> - if ( drhd && drhd->iommu == iommu )
> - return true;
> - }
> -
> - return false;
> -}
> -
> static int domain_context_unmap(struct domain *domain, u8 devfn,
> struct pci_dev *pdev)
> {
> @@ -1704,7 +1728,6 @@ static int domain_context_unmap(struct d
> int ret;
> uint16_t seg = pdev->seg;
> uint8_t bus = pdev->bus, tmp_bus, tmp_devfn, secbus;
> - bool found;
>
> switch ( pdev->type )
> {
> @@ -1780,28 +1803,10 @@ static int domain_context_unmap(struct d
> return -EINVAL;
> }
>
> - if ( ret || QUARANTINE_SKIP(domain) || pdev->devfn != devfn )
> - return ret;
> + if ( !ret && !QUARANTINE_SKIP(domain) && pdev->devfn == devfn )
> + check_cleanup_domid_map(domain, pdev, iommu);
>
> - /*
> - * If no other devices under the same iommu owned by this domain,
> - * clear iommu in iommu_bitmap and clear domain_id in domid_bitmap.
> - */
> - found = any_pdev_behind_iommu(domain, pdev, iommu);
> - /*
> - * Hidden devices are associated with DomXEN but usable by the
> hardware
> - * domain. Hence they need considering here as well.
> - */
> - if ( !found && is_hardware_domain(domain) )
> - found = any_pdev_behind_iommu(dom_xen, pdev, iommu);
> -
> - if ( !found )
> - {
> - clear_bit(iommu->index, dom_iommu(domain)-
> >arch.vtd.iommu_bitmap);
> - cleanup_domid_map(domain, iommu);
> - }
> -
> - return 0;
> + return ret;
> }
>
> static void iommu_clear_root_pgtable(struct domain *d)
