From patchwork Thu Jun 22 23:12:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 9805401 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 425C4600C5 for ; Thu, 22 Jun 2017 23:13:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 264CC28179 for ; Thu, 22 Jun 2017 23:13:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 19543285D5; Thu, 22 Jun 2017 23:13:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7306128179 for ; Thu, 22 Jun 2017 23:13:18 +0000 (UTC) Received: from localhost ([::1]:32932 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dOBHp-00039F-2u for patchwork-qemu-devel@patchwork.kernel.org; Thu, 22 Jun 2017 19:13:17 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44811) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dOBHE-00034E-8Q for qemu-devel@nongnu.org; Thu, 22 Jun 2017 19:12:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dOBHA-0001Cl-1n for qemu-devel@nongnu.org; Thu, 22 Jun 2017 19:12:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54692) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dOBH9-0001CW-Rh for qemu-devel@nongnu.org; Thu, 22 Jun 2017 19:12:35 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7A4A37F40E; Thu, 22 Jun 2017 23:12:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7A4A37F40E Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=david@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 7A4A37F40E Received: from t460s.redhat.com (ovpn-116-89.ams2.redhat.com [10.36.116.89]) by smtp.corp.redhat.com (Postfix) with ESMTP id CEE1968D51; Thu, 22 Jun 2017 23:12:29 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Fri, 23 Jun 2017 01:12:28 +0200 Message-Id: <20170622231228.1050-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 22 Jun 2017 23:12:33 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v1] target-s390x: fix risbg handling X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com, david@redhat.com, agraf@suse.de, Aurelien Jarno , rth@twiddle.net Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP If we have for example: r3 contains 0x00000000ffffffff ec 33 3f bf 61 55 risbg %r3,%r3,63,191,97 We want to rotate 33 to the left and only keep MSB bit 63 of that. So the result is then exactly 1 (we're reading the sign of the 32 bit value). Current code assumes that we can do that via an extract, which is not true (at least not that easy) and produces a 0. Let's just get rid of this special handling. Signed-off-by: David Hildenbrand --- This effectively allows to start a linux kernel, compiled for z10 using the qemu model under tcg (with other patches currently on the list): qemu-system-s390x ... -cpu qemu,mvcos=on,stfle=on,ldisp=on,ldisphp=on, \ eimm=on,stckf=on,csst=on,csst2=on,ginste=on, \ exrl=on ... I found this by compiling the kvm-unit-tests for z10 and noticing elementary selftests failing. The kernel would trigger weird BUG_ONs very early while starting up, which basically gave not really many hints of what was actually going wrong. target/s390x/translate.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/target/s390x/translate.c b/target/s390x/translate.c index 188ab8b..81419dd 100644 --- a/target/s390x/translate.c +++ b/target/s390x/translate.c @@ -3450,12 +3450,6 @@ static ExitStatus op_risbg(DisasContext *s, DisasOps *o) pos += 32; } - /* In some cases we can implement this with extract. */ - if (imask == 0 && pos == 0 && len > 0 && rot + len <= 64) { - tcg_gen_extract_i64(o->out, o->in2, rot, len); - return NO_EXIT; - } - /* In some cases we can implement this with deposit. */ if (len > 0 && (imask == 0 || ~mask == imask)) { /* Note that we rotate the bits to be inserted to the lsb, not to