@@ -887,56 +887,54 @@ static int dma_pte_clear_range(struct dmar_domain *domain,
return order;
}
+static void dma_pte_free_level(struct dmar_domain *domain, int level,
+ struct dma_pte *pte, unsigned long pfn,
+ unsigned long start_pfn, unsigned long last_pfn)
+{
+ pfn = max(start_pfn, pfn);
+ pte = &pte[pfn_level_offset(pfn, level)];
+
+ do {
+ unsigned long level_pfn;
+ struct dma_pte *level_pte;
+
+ if (!dma_pte_present(pte) || dma_pte_superpage(pte))
+ goto next;
+
+ level_pfn = pfn & level_mask(level - 1);
+ level_pte = phys_to_virt(dma_pte_addr(pte));
+
+ if (level > 2)
+ dma_pte_free_level(domain, level - 1, level_pte,
+ level_pfn, start_pfn, last_pfn);
+
+ /* If range covers entire pagetable, free it */
+ if (!(start_pfn > level_pfn ||
+ last_pfn < level_pfn + level_size(level))) {
+ dma_clear_pte(pte);
+ domain_flush_cache(domain, pte, sizeof(*pte));
+ free_pgtable_page(level_pte);
+ }
+next:
+ pfn += level_size(level);
+ } while (!first_pte_in_page(++pte) && pfn <= last_pfn);
+}
+
/* free page table pages. last level pte should already be cleared */
static void dma_pte_free_pagetable(struct dmar_domain *domain,
unsigned long start_pfn,
unsigned long last_pfn)
{
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
- struct dma_pte *first_pte, *pte;
- int total = agaw_to_level(domain->agaw);
- int level;
- unsigned long tmp;
- int large_page = 2;
BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
BUG_ON(start_pfn > last_pfn);
/* We don't need lock here; nobody else touches the iova range */
- level = 2;
- while (level <= total) {
- tmp = align_to_level(start_pfn, level);
-
- /* If we can't even clear one PTE at this level, we're done */
- if (tmp + level_size(level) - 1 > last_pfn)
- return;
-
- do {
- large_page = level;
- first_pte = pte = dma_pfn_level_pte(domain, tmp, level, &large_page);
- if (large_page > level)
- level = large_page + 1;
- if (!pte) {
- tmp = align_to_level(tmp + 1, level + 1);
- continue;
- }
- do {
- if (dma_pte_present(pte)) {
- free_pgtable_page(phys_to_virt(dma_pte_addr(pte)));
- dma_clear_pte(pte);
- }
- pte++;
- tmp += level_size(level);
- } while (!first_pte_in_page(pte) &&
- tmp + level_size(level) - 1 <= last_pfn);
+ dma_pte_free_level(domain, agaw_to_level(domain->agaw),
+ domain->pgd, 0, start_pfn, last_pfn);
- domain_flush_cache(domain, first_pte,
- (void *)pte - (void *)first_pte);
-
- } while (tmp && tmp + level_size(level) - 1 <= last_pfn);
- level++;
- }
/* free pgd */
if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
free_pgtable_page(domain->pgd);
This is a note to let you know that I have just added a patch titled intel-iommu: Fix leaks in pagetable freeing to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.10. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From a2873e196376d5d01e9c7330dc80a066e8878004 Mon Sep 17 00:00:00 2001 From: Alex Williamson <alex.williamson@redhat.com> Date: Sat, 15 Jun 2013 10:27:19 -0600 Subject: intel-iommu: Fix leaks in pagetable freeing commit 3269ee0bd6686baf86630300d528500ac5b516d7 upstream. At best the current code only seems to free the leaf pagetables and the root. If you're unlucky enough to have a large gap (like any QEMU guest with more than 3G of memory), only the first chunk of leaf pagetables are freed (plus the root). This is a massive memory leak. This patch re-writes the pagetable freeing function to use a recursive algorithm and manages to not only free all the pagetables, but does it without any apparent performance loss versus the current broken version. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/iommu/intel-iommu.c | 72 ++++++++++++++++++++++----------------------- 1 file changed, 35 insertions(+), 37 deletions(-) -- 1.8.1.2