[xen staging] AMD/IOMMU: pull ATS disabling earlier

[patchbot@xxxxxxx]

commit 388b5f1be68861b8abaf67e6a311b09b5a0816c5
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Oct 15 12:47:18 2021 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Oct 15 12:47:18 2021 +0200

    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@xxxxxxxx>
    Reviewed-by: Paul Durrant <paul@xxxxxxx>
---
 xen/drivers/passthrough/amd/pci_amd_iommu.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c 
b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 45d16b731f..63fa426273 100644
--- 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,
--
generated by git-patchbot for /home/xen/git/xen.git#staging