Mailing List Archive

# HG changeset patch
# User Keir Fraser <keir@xen.org>
# Date 1293185641 0
# Node ID 7cc87dcf30a13bcf600077aa661694caeb0c290c
# Parent dca1b7cf2e2c27cd160bd1d1d284e3f810d4936c
VT-d: fix and improve print_vtd_entries()

Fix leaking of mapped domain pages (root_entry and ctxt_entry when
falling out of the level traversing loop). Do this by re-arranging
things slightly so that a mapping is retained only as long as it
really is needed.

Fix the failure to use map_domain_page() in the level traversing loop
of the function.

Add a mssing return statement in one of the error paths.

Also I wonder whether not being able to call print_vtd_entries() from
iommu_page_fault_do_one() in ix86 is still correct, now that
map_domain_page() is IRQ safe.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
---
xen/drivers/passthrough/vtd/utils.c | 43 ++++++++++++++++++------------------
1 files changed, 22 insertions(+), 21 deletions(-)

diff -r dca1b7cf2e2c -r 7cc87dcf30a1 xen/drivers/passthrough/vtd/utils.c
--- a/xen/drivers/passthrough/vtd/utils.c Fri Dec 24 10:12:58 2010 +0000
+++ b/xen/drivers/passthrough/vtd/utils.c Fri Dec 24 10:14:01 2010 +0000
@@ -103,7 +103,7 @@ void print_vtd_entries(struct iommu *iom
struct context_entry *ctxt_entry;
struct root_entry *root_entry;
struct dma_pte pte;
- u64 *l;
+ u64 *l, val;
u32 l_index, level;

printk("print_vtd_entries: iommu = %p bdf = %x:%x.%x gmfn = %"PRIx64"\n",
@@ -116,6 +116,11 @@ void print_vtd_entries(struct iommu *iom
}

root_entry = (struct root_entry *)map_vtd_domain_page(iommu->root_maddr);
+ if ( root_entry == NULL )
+ {
+ printk(" root_entry == NULL\n");
+ return;
+ }

printk(" root_entry = %p\n", root_entry);
printk(" root_entry[%x] = %"PRIx64"\n", bus, root_entry[bus].val);
@@ -126,61 +131,57 @@ void print_vtd_entries(struct iommu *iom
return;
}

- ctxt_entry =
- (struct context_entry *)map_vtd_domain_page(root_entry[bus].val);
+ val = root_entry[bus].val;
+ unmap_vtd_domain_page(root_entry);
+ ctxt_entry = map_vtd_domain_page(val);
if ( ctxt_entry == NULL )
{
- unmap_vtd_domain_page(root_entry);
printk(" ctxt_entry == NULL\n");
return;
}

printk(" context = %p\n", ctxt_entry);
+ val = ctxt_entry[devfn].lo;
printk(" context[%x] = %"PRIx64"_%"PRIx64"\n",
- devfn, ctxt_entry[devfn].hi, ctxt_entry[devfn].lo);
+ devfn, ctxt_entry[devfn].hi, val);
if ( !context_present(ctxt_entry[devfn]) )
{
unmap_vtd_domain_page(ctxt_entry);
- unmap_vtd_domain_page(root_entry);
printk(" ctxt_entry[%x] not present\n", devfn);
return;
}

level = agaw_to_level(context_address_width(ctxt_entry[devfn]));
+ unmap_vtd_domain_page(ctxt_entry);
if ( level != VTD_PAGE_TABLE_LEVEL_3 &&
level != VTD_PAGE_TABLE_LEVEL_4)
{
- unmap_vtd_domain_page(ctxt_entry);
- unmap_vtd_domain_page(root_entry);
printk("Unsupported VTD page table level (%d)!\n", level);
- }
-
- l = maddr_to_virt(ctxt_entry[devfn].lo);
+ return;
+ }
+
do
{
- l = (u64*)(((unsigned long)l >> PAGE_SHIFT_4K) << PAGE_SHIFT_4K);
+ l = map_vtd_domain_page(val);
printk(" l%d = %p\n", level, l);
if ( l == NULL )
{
- unmap_vtd_domain_page(ctxt_entry);
- unmap_vtd_domain_page(root_entry);
printk(" l%d == NULL\n", level);
break;
}
l_index = get_level_index(gmfn, level);
printk(" l%d_index = %x\n", level, l_index);
- printk(" l%d[%x] = %"PRIx64"\n", level, l_index, l[l_index]);
-
- pte.val = l[l_index];
+
+ pte.val = val = l[l_index];
+ unmap_vtd_domain_page(l);
+ printk(" l%d[%x] = %"PRIx64"\n", level, l_index, val);
+
+ pte.val = val;
if ( !dma_pte_present(pte) )
{
- unmap_vtd_domain_page(ctxt_entry);
- unmap_vtd_domain_page(root_entry);
printk(" l%d[%x] not present\n", level, l_index);
break;
}
-
- l = maddr_to_virt(l[l_index]);
} while ( --level );
}


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