intel-iommu: Flush unmaps at domain_exit

Backported Alex Williamson's commit to 2.6.32.y
http://git.kernel.org/linus/7b668357810ecb5fdda4418689d50f5d95aea6a8

It resolves the following assert when module is immediately reloaded.

kernel BUG at drivers/pci/iova.c:155!
<snip>
Call Trace:
[<ffffffff812645c5>] intel_alloc_iova+0xb5/0xe0
[<ffffffff8126725e>] __intel_map_single+0xbe/0x210
[<ffffffff812674ae>] intel_alloc_coherent+0xae/0x120
[<ffffffffa035f909>] be_queue_alloc+0xb9/0x140 [be2net]
[<ffffffffa035fa5a>] be_rx_qs_create+0xca/0x370 [be2net]
<snip>

The issue is reproducible in 2.6.32.60 and also gets resolved
by passing intel-iommu=strict to kernel.

Signed-off-by: Jitendra Bhivare <jitendra.bhivare@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 5b680dfd871e8e65e55efa3d33189e59bb7897f5..c1a7b01aa0597dead67795bbd0a532a7ea1fa665 100644 (file)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1434,6 +1434,10 @@ static void domain_exit(struct dmar_domain *domain)
        if (!domain)
                return;
 
+       /* Flush any lazy unmaps that may reference this domain */
+       if (!intel_iommu_strict)
+               flush_unmaps_timeout(0);
+
        domain_remove_dev_info(domain);
        /* destroy iovas */
        put_iova_domain(&domain->iovad);