VT-d: make print_vtd_entries() less verbose

Especially printing virtual addresses of mappings of the individual
pages seems rather useless here - this mostly obfuscates the important
numbers, and hinders comparing two printouts. Printing the page table
level indexes isn't very useful either, as the immediately following
lines will print the indexes again as part of printing the raw entries.

Take the opportunity and also
- adjust some format specifiers,
- widen (zero-pad) array indexes to their nominal width.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
I also wonder whether the three "... not present" messages are really
all that useful, especially when an entry is zero - they all follow
messages with the respective full entry.

--- a/xen/drivers/passthrough/vtd/utils.c
+++ b/xen/drivers/passthrough/vtd/utils.c
@@ -95,8 +95,8 @@ void print_vtd_entries(struct iommu *iom
     u64 *l, val;
     u32 l_index, level;
 
-    printk("print_vtd_entries: iommu %p dev %04x:%02x:%02x.%u gmfn %"PRIx64"\n",
-           iommu, iommu->intel->drhd->segment, bus,
+    printk("print_vtd_entries: iommu #%u dev %04x:%02x:%02x.%u gmfn %"PRI_gfn"\n",
+           iommu->index, iommu->intel->drhd->segment, bus,
            PCI_SLOT(devfn), PCI_FUNC(devfn), gmfn);
 
     if ( iommu->root_maddr == 0 )
@@ -112,12 +112,11 @@ void print_vtd_entries(struct iommu *iom
         return;
     }
 
-    printk("    root_entry = %p\n", root_entry);
-    printk("    root_entry[%x] = %"PRIx64"\n", bus, root_entry[bus].val);
+    printk("    root_entry[%02x] = %"PRIx64"\n", bus, root_entry[bus].val);
     if ( !root_present(root_entry[bus]) )
     {
         unmap_vtd_domain_page(root_entry);
-        printk("    root_entry[%x] not present\n", bus);
+        printk("    root_entry[%02x] not present\n", bus);
         return;
     }
 
@@ -130,14 +129,13 @@ void print_vtd_entries(struct iommu *iom
         return;
     }
 
-    printk("    context = %p\n", ctxt_entry);
     val = ctxt_entry[devfn].lo;
-    printk("    context[%x] = %"PRIx64"_%"PRIx64"\n",
+    printk("    context[%02x] = %"PRIx64"_%"PRIx64"\n",
            devfn, ctxt_entry[devfn].hi, val);
     if ( !context_present(ctxt_entry[devfn]) )
     {
         unmap_vtd_domain_page(ctxt_entry);
-        printk("    ctxt_entry[%x] not present\n", devfn);
+        printk("    ctxt_entry[%02x] not present\n", devfn);
         return;
     }
 
@@ -153,22 +151,19 @@ void print_vtd_entries(struct iommu *iom
     do
     {
         l = map_vtd_domain_page(val);
-        printk("    l%d = %p\n", level, l);
         if ( l == NULL )
         {
-            printk("    l%d == NULL\n", level);
+            printk("    l%u == NULL\n", level);
             break;
         }
         l_index = get_level_index(gmfn, level);
-        printk("    l%d_index = %x\n", level, l_index);
-
         pte.val = l[l_index];
         unmap_vtd_domain_page(l);
-        printk("    l%d[%x] = %"PRIx64"\n", level, l_index, pte.val);
+        printk("    l%u[%03x] = %"PRIx64"\n", level, l_index, pte.val);
 
         if ( !dma_pte_present(pte) )
         {
-            printk("    l%d[%x] not present\n", level, l_index);
+            printk("    l%u[%03x] not present\n", level, l_index);
             break;
         }
         if ( dma_pte_superpage(pte) )