From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 2 Jun 2008 09:04:19 +0000 (+0100)
Subject: vtd: Fix pagetable teardown on domain detsruction.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14200^2~110
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=a42d40a38b0bb2ac25b714b3573befc2877f6648;p=xen.git

vtd: Fix pagetable teardown on domain detsruction.
Signed-off-by: Xiaowei Yang <xiaowei.yang@intel.com>
---

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 3913b31e9e..aa3d7a0bf7 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -587,50 +587,32 @@ static void dma_pte_clear_range(struct domain *domain, u64 start, u64 end)
     }
 }
 
-static void iommu_free_next_pagetable(u64 pt_maddr, unsigned long index,
-                                      int level)
+static void iommu_free_pagetable(u64 pt_maddr, int level)
 {
-    unsigned long next_index;
-    struct dma_pte *pt_vaddr, *pde;
-    int next_level;
+    int i;
+    struct dma_pte *pt_vaddr, *pte;
+    int next_level = level - 1;
 
     if ( pt_maddr == 0 )
         return;
 
     pt_vaddr = (struct dma_pte *)map_vtd_domain_page(pt_maddr);
-    pde = &pt_vaddr[index];
-    if ( dma_pte_addr(*pde) == 0 )
-        goto out;
 
-    next_level = level - 1;
-    if ( next_level > 1 )
+    for ( i = 0; i < PTE_NUM; i++ )
     {
-        for ( next_index = 0; next_index < PTE_NUM; next_index++ )
-            iommu_free_next_pagetable(pde->val, next_index, next_level);
-    }
-
-    dma_clear_pte(*pde);
-    iommu_flush_cache_entry(pde);
-    free_pgtable_maddr(pde->val);
-
- out:
-    unmap_vtd_domain_page(pt_vaddr);
-}
-
-/* free all VT-d page tables when shut down or destroy domain. */
-static void iommu_free_pagetable(struct domain *domain)
-{
-    struct hvm_iommu *hd = domain_hvm_iommu(domain);
-    int i, total_level = agaw_to_level(hd->agaw);
+        pte = &pt_vaddr[i];
+        if ( !dma_pte_present(*pte) )
+            continue;
 
-    if ( hd->pgd_maddr == 0 )
-        return;
+        if ( next_level >= 1 )
+            iommu_free_pagetable(dma_pte_addr(*pte), next_level);
 
-    for ( i = 0; i < PTE_NUM; i++ )
-        iommu_free_next_pagetable(hd->pgd_maddr, i, total_level + 1);
+        dma_clear_pte(*pte);
+        iommu_flush_cache_entry(pte);
+    }
 
-    free_pgtable_maddr(hd->pgd_maddr);
-    hd->pgd_maddr = 0;
+    unmap_vtd_domain_page(pt_vaddr);
+    free_pgtable_maddr(pt_maddr);
 }
 
 static int iommu_set_root_entry(struct iommu *iommu)
@@ -1456,11 +1438,14 @@ void return_devices_to_dom0(struct domain *d)
 
 void iommu_domain_teardown(struct domain *d)
 {
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+
     if ( list_empty(&acpi_drhd_units) )
         return;
 
-    iommu_free_pagetable(d);
     return_devices_to_dom0(d);
+    iommu_free_pagetable(hd->pgd_maddr, agaw_to_level(hd->agaw));
+    hd->pgd_maddr = 0;
     iommu_domid_release(d);
 }