@@ -178,7 +178,8 @@ void __init iommu_dte_add_device_entry(s
* page tables.
*/
static int iommu_pde_from_dfn(struct domain *d, unsigned long dfn,
- unsigned long *pt_mfn, bool map)
+ unsigned int target, unsigned long *pt_mfn,
+ bool map)
{
union amd_iommu_pte *pde, *next_table_vaddr;
unsigned long next_table_mfn;
@@ -189,7 +190,8 @@ static int iommu_pde_from_dfn(struct dom
table = hd->arch.amd.root_table;
level = hd->arch.amd.paging_mode;
- BUG_ON( table == NULL || level < 1 || level > 6 );
+ if ( !table || target < 1 || level < target || level > 6 )
+ return 1;
/*
* A frame number past what the current page tables can represent can't
@@ -200,7 +202,7 @@ static int iommu_pde_from_dfn(struct dom
next_table_mfn = mfn_x(page_to_mfn(table));
- while ( level > 1 )
+ while ( level > target )
{
unsigned int next_level = level - 1;
@@ -307,7 +309,7 @@ int amd_iommu_map_page(struct domain *d,
return rc;
}
- if ( iommu_pde_from_dfn(d, dfn_x(dfn), &pt_mfn, true) || !pt_mfn )
+ if ( iommu_pde_from_dfn(d, dfn_x(dfn), 1, &pt_mfn, true) || !pt_mfn )
{
spin_unlock(&hd->arch.mapping_lock);
AMD_IOMMU_DEBUG("Invalid IO pagetable entry dfn = %"PRI_dfn"\n",
@@ -340,7 +342,7 @@ int amd_iommu_unmap_page(struct domain *
return 0;
}
- if ( iommu_pde_from_dfn(d, dfn_x(dfn), &pt_mfn, false) )
+ if ( iommu_pde_from_dfn(d, dfn_x(dfn), 1, &pt_mfn, false) )
{
spin_unlock(&hd->arch.mapping_lock);
AMD_IOMMU_DEBUG("Invalid IO pagetable entry dfn = %"PRI_dfn"\n",
In order to be able to insert/remove super-pages we need to allow callers of the walking function to specify at which point to stop the walk. (For now at least gcc will instantiate just a variant of the function with the parameter eliminated, so effectively no change to generated code as far as the parameter addition goes.) Instead of merely adjusting a BUG_ON() condition, convert it into an error return - there's no reason to crash the entire host in that case. Signed-off-by: Jan Beulich <jbeulich@suse.com>