From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38649) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUSnT-00063W-Ba for qemu-devel@nongnu.org; Fri, 20 Jan 2017 01:35:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUSnO-0005LM-Cd for qemu-devel@nongnu.org; Fri, 20 Jan 2017 01:35:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51392) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cUSnO-0005Kn-1D for qemu-devel@nongnu.org; Fri, 20 Jan 2017 01:35:34 -0500 Received: from smtp.corp.redhat.com (int-mx16.intmail.prod.int.phx2.redhat.com [10.5.11.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BEB72BDD4 for ; Fri, 20 Jan 2017 06:35:33 +0000 (UTC) From: Jason Wang Date: Fri, 20 Jan 2017 14:35:28 +0800 Message-Id: <1484894128-7871-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH] intel_iommu: fix and simplify size calculation in process_device_iotlb_desc() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mst@redhat.com, Jason Wang , Paolo Bonzini 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 --- 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