From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06746C432C0 for ; Fri, 22 Nov 2019 10:55:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD2272075E for ; Fri, 22 Nov 2019 10:55:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574420148; bh=xYtSWAppVOZfMLxMc2is88PZzdaTy5OfeiBTGRCVlDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DRNHdR5vcflzZV70mu7iObdeH4WtQyegDOHQM8qCWKL8kG91idE7YZVIy6fFV813K QB2cO8zqPOvQAG5C2Saz+jmrPrUjXFV2px4dDwrWD+1Pquzoo3NTOlmOi8EnZpgWjP +7E0SmHkempqbXSdp7VFJxuN+O/c1mSvsenmI1Zg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730500AbfKVKzn (ORCPT ); Fri, 22 Nov 2019 05:55:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:42778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730205AbfKVKzn (ORCPT ); Fri, 22 Nov 2019 05:55:43 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A861120637; Fri, 22 Nov 2019 10:55:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574420142; bh=xYtSWAppVOZfMLxMc2is88PZzdaTy5OfeiBTGRCVlDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NPruWco1qtvCNm1EJU3HO82NbgwdQ0XUNNL3QjB6dSXU7mnoI11YMTrVGECL69I2R RXPOhIf2A13Pmn4YuDOxAs2hLgcjqnJbAQbFhwmfOYE6EVKxebflyziHoZAkCB9BTa ocTexugw/OtUPsUf+0TFitJAnuR2n5rUzrM9uzv8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Ellerman , Sasha Levin Subject: [PATCH 4.14 121/122] powerpc/time: Fix clockevent_decrementer initalisation for PR KVM Date: Fri, 22 Nov 2019 11:29:34 +0100 Message-Id: <20191122100837.967736873@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191122100722.177052205@linuxfoundation.org> References: <20191122100722.177052205@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Ellerman [ Upstream commit b4d16ab58c41ff0125822464bdff074cebd0fe47 ] In the recent commit 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer") we changed the way we initialise the decrementer clockevent(s). We no longer initialise the mult & shift values of decrementer_clockevent itself. This has the effect of breaking PR KVM, because it uses those values in kvmppc_emulate_dec(). The symptom is guest kernels spin forever mid-way through boot. For now fix it by assigning back to decrementer_clockevent the mult and shift values. Fixes: 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer") Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/kernel/time.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 870e75d304591..7c7c5a16284d2 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -988,6 +988,10 @@ static void register_decrementer_clockevent(int cpu) printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", dec->name, dec->mult, dec->shift, cpu); + + /* Set values for KVM, see kvm_emulate_dec() */ + decrementer_clockevent.mult = dec->mult; + decrementer_clockevent.shift = dec->shift; } static void enable_large_decrementer(void) -- 2.20.1