From 04eb6247eb1d95728b1e3e0078ba79f5b6d2ac25 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Fri, 20 Jan 2017 14:35:28 +0800 Subject: 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 Cc: Paolo Bonzini Signed-off-by: Jason Wang Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Paolo Bonzini --- hw/i386/intel_iommu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'hw/i386') 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; -- cgit v1.2.1