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authorJason Wang <jasowang@redhat.com>2017-01-20 14:35:28 +0800
committerMichael S. Tsirkin <mst@redhat.com>2017-02-01 03:37:17 +0200
commit04eb6247eb1d95728b1e3e0078ba79f5b6d2ac25 (patch)
tree3f4b8cc82f5fc3ebbfe852b9e06e16a8f8c421b4 /hw/i386
parentec42813028d9ede3f9f73b8c943b00ff235ba0c1 (diff)
downloadqemu-04eb6247eb1d95728b1e3e0078ba79f5b6d2ac25.tar.gz
intel_iommu: fix and simplify size calculation in process_device_iotlb_desc()
We don't use 1ULL which is wrong during size calculation. Fix it, and while at it, switch to use cto64() and adds a comments to make it simpler and easier to be understood. Reported-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw/i386')
-rw-r--r--hw/i386/intel_iommu.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index ec62239aba..3270fb9162 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1485,8 +1485,16 @@ static bool vtd_process_device_iotlb_desc(IntelIOMMUState *s,
goto done;
}
+ /* According to ATS spec table 2.4:
+ * S = 0, bits 15:12 = xxxx range size: 4K
+ * S = 1, bits 15:12 = xxx0 range size: 8K
+ * S = 1, bits 15:12 = xx01 range size: 16K
+ * S = 1, bits 15:12 = x011 range size: 32K
+ * S = 1, bits 15:12 = 0111 range size: 64K
+ * ...
+ */
if (size) {
- sz = 1 << (ctz64(~(addr | (VTD_PAGE_MASK_4K - 1))) + 1);
+ sz = (VTD_PAGE_SIZE * 2) << cto64(addr >> VTD_PAGE_SHIFT);
addr &= ~(sz - 1);
} else {
sz = VTD_PAGE_SIZE;