[PATCH 3.14 78/78] [stable PATCH] iommu/vt-d: Fix missing IOTLB flush in intel_iommu_unmap()

Greg Kroah-Hartman
2014-06-09T22:46:47Z

From: David Woodhouse <dwmw2@infradead.org>

Based on commit ea8ea460c9ace60bbb5ac6e5521d637d5c15293d upstream

This missing IOTLB flush was added as a minor, inconsequential bug-fix
in commit ea8ea460c ("iommu/vt-d: Clean up and fix page table clear/free
behaviour") in 3.15. It wasn't originally intended for -stable but a
couple of users have reported issues which turn out to be fixed by
adding the missing flush.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
For 3.14 and earlier. As noted, this fix is in 3.15 already.

drivers/iommu/intel-iommu.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4075,7 +4075,7 @@ static size_t intel_iommu_unmap(struct i
unsigned long iova, size_t size)
{
struct dmar_domain *dmar_domain = domain->priv;
- int order;
+ int order, iommu_id;

order = dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
(iova + size - 1) >> VTD_PAGE_SHIFT);
@@ -4083,6 +4083,22 @@ static size_t intel_iommu_unmap(struct i
if (dmar_domain->max_addr == iova + size)
dmar_domain->max_addr = iova;

+ for_each_set_bit(iommu_id, dmar_domain->iommu_bmp, g_num_of_iommus) {
+ struct intel_iommu *iommu = g_iommus[iommu_id];
+ int num, ndomains;
+
+ /*
+ * find bit position of dmar_domain
+ */
+ ndomains = cap_ndoms(iommu->cap);
+ for_each_set_bit(num, iommu->domain_ids, ndomains) {
+ if (iommu->domains[num] == dmar_domain)
+ iommu_flush_iotlb_psi(iommu, num,
+ iova >> VTD_PAGE_SHIFT,
+ 1 << order, 0);
+ }
+ }
+
return PAGE_SIZE << order;
}