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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C3878C43331 for ; Wed, 13 Nov 2019 02:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8FA3B222C1 for ; Wed, 13 Nov 2019 02:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573611441; bh=ETy3/oLlODMF6IqyyikE3r7NS0VCBoZzrTvaSa//SfQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IHH2DXeq+W1c13XxCqhLmHiZjrymcgKJiLIaCUB3mNomdfeiclcJ6b3boefwm3Owb DAfYRUfj+aP4J8uH6i6JNWTG1ZUnhz86Och6+QeSumv+NDft7uyUeEmAM0uMSfY3KQ h7fEBKgggI/imY/pF87SpGNR81llwVMf34in7Q/M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729795AbfKMCRU (ORCPT ); Tue, 12 Nov 2019 21:17:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:48134 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727412AbfKMB4G (ORCPT ); Tue, 12 Nov 2019 20:56:06 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C4307222CF; Wed, 13 Nov 2019 01:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573610166; bh=ETy3/oLlODMF6IqyyikE3r7NS0VCBoZzrTvaSa//SfQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EavFTl58i4xagNZZMB5z3YiC1bALAzr29wT70OVM2lXTG0Lju8QyNSzw0jnilS7FO W5rUSAOUOfAFd3Dv4yDW5HFXkVCNlIfVJynqHiqZO2tfwrKADUnTjFVAcWZ5JxNe6A Kb/AVhHxk1qh+QTyuCdf5+bE2A+7sxu6VWte0+p0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 4.19 207/209] powerpc/time: Fix clockevent_decrementer initalisation for PR KVM Date: Tue, 12 Nov 2019 20:50:23 -0500 Message-Id: <20191113015025.9685-207-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191113015025.9685-1-sashal@kernel.org> References: <20191113015025.9685-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 6a1f0a084ca35..7707990c4c169 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