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[Qemu-devel] [PATCH] intel_iommu: fix and simplify size calculation in p
From: |
Jason Wang |
Subject: |
[Qemu-devel] [PATCH] intel_iommu: fix and simplify size calculation in process_device_iotlb_desc() |
Date: |
Fri, 20 Jan 2017 14:35:28 +0800 |
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 <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Signed-off-by: Jason Wang <address@hidden>
---
hw/i386/intel_iommu.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index ec62239..3270fb9 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;
--
2.7.4
- [Qemu-devel] [PATCH] intel_iommu: fix and simplify size calculation in process_device_iotlb_desc(),
Jason Wang <=