[Xen-devel] [PATCH] VT-d: IOTLB flush fixups

[Espen Skoglund <espen.skoglund@xxxxxxxxxxxxx>]

On map: only flush when old PTE was valid or invalid PTE may be cached.
On unmap: always flush old entry, but skip flush for unaffected IOMMUs.

Signed-off-by: Espen Skoglund <espen.skoglund@xxxxxxxxxxxxx>

--
 iommu.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
--
diff -r 8187fd8113f9 xen/drivers/passthrough/vtd/iommu.c
--- a/xen/drivers/passthrough/vtd/iommu.c       Tue May 27 11:46:52 2008 +0100
+++ b/xen/drivers/passthrough/vtd/iommu.c       Tue May 27 17:16:51 2008 +0100
@@ -1525,6 +1525,7 @@
     struct iommu *iommu;
     struct dma_pte *page = NULL, *pte = NULL;
     u64 pg_maddr;
+    int pte_present;
 
     drhd = list_entry(acpi_drhd_units.next, typeof(*drhd), list);
     iommu = drhd->iommu;
@@ -1540,6 +1541,7 @@
         return -ENOMEM;
     page = (struct dma_pte *)map_vtd_domain_page(pg_maddr);
     pte = page + (gfn & LEVEL_MASK);
+    pte_present = dma_pte_present(*pte);
     dma_set_pte_addr(*pte, (paddr_t)mfn << PAGE_SHIFT_4K);
     dma_set_pte_prot(*pte, DMA_PTE_READ | DMA_PTE_WRITE);
     iommu_flush_cache_entry(iommu, pte);
@@ -1552,7 +1554,7 @@
         if ( !test_bit(iommu->index, &hd->iommu_bitmap) )
             continue;
 
-        if ( cap_caching_mode(iommu->cap) )
+        if ( pte_present || cap_caching_mode(iommu->cap) )
             iommu_flush_iotlb_psi(iommu, domain_iommu_domid(d),
                                   (paddr_t)gfn << PAGE_SHIFT_4K, 1, 0);
         else if ( cap_rwbf(iommu->cap) )
@@ -1564,6 +1566,7 @@
 
 int intel_iommu_unmap_page(struct domain *d, unsigned long gfn)
 {
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
     struct acpi_drhd_unit *drhd;
     struct iommu *iommu;
     struct dma_pte *page = NULL, *pte = NULL;
@@ -1590,11 +1593,13 @@
     for_each_drhd_unit ( drhd )
     {
         iommu = drhd->iommu;
-        if ( cap_caching_mode(iommu->cap) )
-            iommu_flush_iotlb_psi(iommu, domain_iommu_domid(d),
-                                  (paddr_t)gfn << PAGE_SHIFT_4K, 1, 0);
-        else if ( cap_rwbf(iommu->cap) )
-            iommu_flush_write_buffer(iommu);
+ 
+        if ( !test_bit(iommu->index, &hd->iommu_bitmap) )
+            continue;
+
+       if ( iommu_flush_iotlb_psi(iommu, domain_iommu_domid(d),
+                                  (paddr_t)gfn << PAGE_SHIFT_4K, 1, 0) )
+           iommu_flush_write_buffer(iommu);
     }
 
     return 0;

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel