From nobody Wed Nov 5 11:35:22 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1498173210627473.30236609174824; Thu, 22 Jun 2017 16:13:30 -0700 (PDT) Received: from localhost ([::1]:32933 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dOBI0-0003RH-1K for importer@patchew.org; Thu, 22 Jun 2017 19:13:28 -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) 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) 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 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Aurelien Jarno --- 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=3Don,stfle=3Don,ldisp=3Don,ldisphp=3D= on, \ eimm=3Don,stckf=3Don,csst=3Don,csst2=3Don,ginste= =3Don, \ exrl=3Don ... 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 +=3D 32; } =20 - /* In some cases we can implement this with extract. */ - if (imask =3D=3D 0 && pos =3D=3D 0 && len > 0 && rot + len <=3D 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 =3D=3D 0 || ~mask =3D=3D imask)) { /* Note that we rotate the bits to be inserted to the lsb, not to --=20 2.9.4