From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55180) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dFxBx-0005nH-7K for qemu-devel@nongnu.org; Wed, 31 May 2017 02:33:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dFxBt-0004Ul-B1 for qemu-devel@nongnu.org; Wed, 31 May 2017 02:33:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44074) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dFxBt-0004TK-5y for qemu-devel@nongnu.org; Wed, 31 May 2017 02:33:09 -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 285A94E4CD for ; Wed, 31 May 2017 06:33:08 +0000 (UTC) From: Peter Xu Date: Wed, 31 May 2017 14:32:58 +0800 Message-Id: <1496212378-22605-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [PATCH v3] 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 --- v3: - use pow2floor() [Paolo] --- exec.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/exec.c b/exec.c index b1db12f..8fc0e78 100644 --- a/exec.c +++ b/exec.c @@ -530,16 +530,14 @@ 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 = pow2floor(plen) - 1; } - /* Convert to address mask */ - plen -= 1; - return (IOMMUTLBEntry) { .target_as = section.address_space, .iova = addr & ~plen, -- 2.7.4