From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42394) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dFBtA-0008WS-8l for qemu-devel@nongnu.org; Mon, 29 May 2017 00:02:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dFBt7-0006EG-6M for qemu-devel@nongnu.org; Mon, 29 May 2017 00:02:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35546) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dFBt7-0006EC-0P for qemu-devel@nongnu.org; Mon, 29 May 2017 00:02:37 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3AC695372 for ; Mon, 29 May 2017 04:02:35 +0000 (UTC) From: Peter Xu Date: Mon, 29 May 2017 12:02:25 +0800 Message-Id: <1496030545-8719-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [PATCH v2] exec: fix address_space_get_iotlb_entry page mask List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Maxime Coquelin , peterx@redhat.com The IOTLB that it returned didn't guarantee that page_mask is indeed a so-called page mask. That won't affect current usage since now only vhost is using it (vhost API allows arbitary IOTLB range). However we have IOTLB scemantic and we should best follow it. This patch fixes this issue to make sure the page_mask is always a valid page mask. Fixes: a764040 ("exec: abstract address_space_do_translate()") Signed-off-by: Peter Xu --- Sorry please use this one. The codes is merely the same, just avoided moving the codes around unnecessarily. --- exec.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/exec.c b/exec.c index ff16f04..3db247c 100644 --- a/exec.c +++ b/exec.c @@ -529,16 +529,14 @@ IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr, section.offset_within_region; if (plen == (hwaddr)-1) { - /* - * We use default page size here. Logically it only happens - * for identity mappings. - */ - plen = TARGET_PAGE_SIZE; + /* If not specified during translation, use default mask */ + plen = TARGET_PAGE_MASK; + } else { + /* Make it a valid page mask */ + assert(plen); + plen = (1ULL << (63 - clz64(plen))) - 1; } - /* Convert to address mask */ - plen -= 1; - return (IOMMUTLBEntry) { .target_as = section.address_space, .iova = addr & ~plen, -- 2.7.4