From c5b1525533c484238015c48c78f86d49a1bfb86b Mon Sep 17 00:00:00 2001
From: Sheng Yang <sheng@linux.intel.com>
Date: Thu, 6 Aug 2009 13:31:56 +0800
Subject: [PATCH] intel-iommu: Fix enabling snooping feature by mistake
Two defects work together result in KVM device passthrough randomly can't
work:
1. iommu_snooping is not initialized to zero when vm_iommu_init() called.
So it is possible to get a random value.
2. One line added by commit 2c2e2c38("IOMMU Identity Mapping Support")
change the code path, let it bypass domain_update_iommu_cap(), as well as
missing the increment of domain iommu reference count.
The latter is also likely to cause a leak of domains on repeated VMM
assignment and deassignment.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
drivers/pci/intel-iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index af7ff9b5aed88..2314ad7ee5fef 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1505,7 +1505,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain, int segment,
}
set_bit(num, iommu->domain_ids);
- set_bit(iommu->seq_id, &domain->iommu_bmp);
iommu->domains[num] = domain;
id = num;
}
@@ -3409,6 +3408,7 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
domain->iommu_count = 0;
domain->iommu_coherency = 0;
+ domain->iommu_snooping = 0;
domain->max_addr = 0;
/* always allocate the top pgd */
--
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