AMD/IOMMU: pull ATS disabling earlier

Disabling should be done in the opposite order of enabling: ATS wants to
be turned off before adjusting the DTE, just like it gets enabled only
after the DTE was suitably prepared. Note that we want ATS to be
disabled as soon as any of the DTEs involved in the handling of a device
(including phantom devices) gets adjusted respectively. For this reason
the "devfn == pdev->devfn" of the original conditional gets dropped.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>

diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 45d16b731fc1c3d91591df75b4a15659717f91a3..63fa426273072bfa407781a2b0d86d0938ad3e20 100644 (file)
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -313,6 +313,12 @@ static void amd_iommu_disable_domain_device(const struct domain *domain,
     if ( QUARANTINE_SKIP(domain) )
         return;
 
+    ASSERT(pcidevs_locked());
+
+    if ( pci_ats_device(iommu->seg, bus, pdev->devfn) &&
+         pci_ats_enabled(iommu->seg, bus, pdev->devfn) )
+        disable_ats_device(pdev);
+
     BUG_ON ( iommu->dev_table.buffer == NULL );
     req_id = get_dma_requestor_id(iommu->seg, PCI_BDF2(bus, devfn));
     table = iommu->dev_table.buffer;
@@ -348,13 +354,6 @@ static void amd_iommu_disable_domain_device(const struct domain *domain,
     }
     else
         spin_unlock_irqrestore(&iommu->lock, flags);
-
-    ASSERT(pcidevs_locked());
-
-    if ( devfn == pdev->devfn &&
-         pci_ats_device(iommu->seg, bus, devfn) &&
-         pci_ats_enabled(iommu->seg, bus, devfn) )
-        disable_ats_device(pdev);
 }
 
 static int reassign_device(struct domain *source, struct domain *target,