File xsa400-09.patch of Package xen.27494

IOMMU/x86: drop TLB flushes from quarantine_init() hooks

The page tables just created aren't hooked up yet anywhere, so there's
nothing that could be present in any TLB, and hence nothing to flush.
Dropping this flush is, at least on the VT-d side, a prereq to per-
device domain ID use when quarantining devices, as dom_io isn't going
to be assigned a DID anymore: The warning in get_iommu_did() would
trigger.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -843,8 +843,6 @@ int __init amd_iommu_quarantine_init(str
  out:
     spin_unlock(&hd->arch.mapping_lock);
 
-    amd_iommu_flush_all_pages(d);
-
     /* Pages leaked in failure case */
     return level ? -ENOMEM : 0;
 }
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2935,7 +2935,6 @@ static int __init intel_iommu_quarantine
     struct dma_pte *parent;
     unsigned int agaw = width_to_agaw(DEFAULT_DOMAIN_ADDRESS_WIDTH);
     unsigned int level = agaw_to_level(agaw);
-    int rc;
 
     if ( hd->arch.pgd_maddr )
     {
@@ -2982,10 +2981,8 @@ static int __init intel_iommu_quarantine
  out:
     spin_unlock(&hd->arch.mapping_lock);
 
-    rc = iommu_flush_iotlb_all(d);
-
     /* Pages leaked in failure case */
-    return level ? -ENOMEM : rc;
+    return level ? -ENOMEM : 0;
 }
 
 const struct iommu_ops __initconstrel intel_iommu_ops = {