From patchwork Mon Jan 25 01:15:18 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 8103121 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id A57D89F6DA for ; Mon, 25 Jan 2016 01:25:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 11F95203A0 for ; Mon, 25 Jan 2016 01:25:57 +0000 (UTC) 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.kernel.org (Postfix) with ESMTPS id 5BD142038D for ; Mon, 25 Jan 2016 01:25:56 +0000 (UTC) Received: from localhost ([::1]:34095 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNVul-00084d-N9 for patchwork-qemu-devel@patchwork.kernel.org; Sun, 24 Jan 2016 20:25:55 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47767) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNVjq-0002af-Up for qemu-devel@nongnu.org; Sun, 24 Jan 2016 20:14:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aNVjo-0000dp-Hu for qemu-devel@nongnu.org; Sun, 24 Jan 2016 20:14:38 -0500 Received: from ozlabs.org ([2401:3900:2:1::2]:48150) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNVjo-0000az-3D; Sun, 24 Jan 2016 20:14:36 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id A98B8140BCE; Mon, 25 Jan 2016 12:14:32 +1100 (AEDT) From: David Gibson To: peter.maydell@linaro.org Date: Mon, 25 Jan 2016 12:15:18 +1100 Message-Id: <1453684527-23564-20-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1453684527-23564-1-git-send-email-david@gibson.dropbear.id.au> References: <1453684527-23564-1-git-send-email-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2401:3900:2:1::2 Cc: lvivier@redhat.com, thuth@redhat.com, mark.cave-ayland@ilande.co.uk, agraf@suse.de, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, bharata@linux.vnet.ibm.com, David Gibson , gkurz@linux.vnet.ibm.com Subject: [Qemu-devel] [PULL 19/28] target-ppc: kvm: fix floating point registers sync on little-endian hosts X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Greg Kurz On VSX capable CPUs, the 32 FP registers are mapped to the high-bits of the 32 first VSX registers. So if you have: VSR31 = (uint128) 0x0102030405060708090a0b0c0d0e0f00 then FPR31 = (uint64) 0x0102030405060708 The kernel stores the VSX registers in the fp_state struct following the host endian element ordering. On big-endian: fp_state.fpr[31][0] = 0x0102030405060708 fp_state.fpr[31][1] = 0x090a0b0c0d0e0f00 On little-endian: fp_state.fpr[31][0] = 0x090a0b0c0d0e0f00 fp_state.fpr[31][1] = 0x0102030405060708 The KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctls preserve this ordering, but QEMU considers it as big-endian and always copies element [0] to the fpr[] array and element [1] to the vsr[] array. This does not work with little-endian hosts, and you will get: (qemu) p $f31 0x90a0b0c0d0e0f00 instead of: (qemu) p $f31 0x102030405060708 This patch fixes the element ordering for little-endian hosts. Signed-off-by: Greg Kurz Signed-off-by: David Gibson --- target-ppc/kvm.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 9940a90..4524999 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -650,8 +650,13 @@ static int kvm_put_fp(CPUState *cs) for (i = 0; i < 32; i++) { uint64_t vsr[2]; +#ifdef HOST_WORDS_BIGENDIAN vsr[0] = float64_val(env->fpr[i]); vsr[1] = env->vsr[i]; +#else + vsr[0] = env->vsr[i]; + vsr[1] = float64_val(env->fpr[i]); +#endif reg.addr = (uintptr_t) &vsr; reg.id = vsx ? KVM_REG_PPC_VSR(i) : KVM_REG_PPC_FPR(i); @@ -721,10 +726,17 @@ static int kvm_get_fp(CPUState *cs) vsx ? "VSR" : "FPR", i, strerror(errno)); return ret; } else { +#ifdef HOST_WORDS_BIGENDIAN env->fpr[i] = vsr[0]; if (vsx) { env->vsr[i] = vsr[1]; } +#else + env->fpr[i] = vsr[1]; + if (vsx) { + env->vsr[i] = vsr[0]; + } +#endif } } }