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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 AB855C04AB5 for ; Mon, 3 Jun 2019 12:41:18 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3F5342807A for ; Mon, 3 Jun 2019 12:41:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F5342807A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45HZRc0CRkzDqSB for ; Mon, 3 Jun 2019 22:41:16 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45HZFv73SQzDqKX for ; Mon, 3 Jun 2019 22:32:51 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 45HZFv4jpmz9sNm; Mon, 3 Jun 2019 22:32:51 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: a3bf9fbdad600b1e4335dd90979f8d6072e4f602 X-Patchwork-Hint: ignore Content-Type: text/plain; charset="utf-8"; In-Reply-To: <155791470178.432724.8008395673479905061.stgit@bahia.lan> To: Greg Kurz , Paul Mackerras , Benjamin Herrenschmidt From: Michael Ellerman Subject: Re: [PATCH] powerpc/pseries: Fix xive=off command line Message-Id: <45HZFv4jpmz9sNm@ozlabs.org> Date: Mon, 3 Jun 2019 22:32:51 +1000 (AEST) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pavrampu@in.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, =?utf-8?b?Q8Op?= =?utf-8?q?dric?= Le Goater Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 2019-05-15 at 10:05:01 UTC, Greg Kurz wrote: > On POWER9, if the hypervisor supports XIVE exploitation mode, the guest OS > will unconditionally requests for the XIVE interrupt mode even if XIVE was > deactivated with the kernel command line xive=off. Later on, when the spapr > XIVE init code handles xive=off, it disables XIVE and tries to fall back on > the legacy mode XICS. > > This discrepency causes a kernel panic because the hypervisor is configured > to provide the XIVE interrupt mode to the guest : > > [ 0.008837] kernel BUG at arch/powerpc/sysdev/xics/xics-common.c:135! > [ 0.008877] Oops: Exception in kernel mode, sig: 5 [#1] > [ 0.008908] LE SMP NR_CPUS=1024 NUMA pSeries > [ 0.008939] Modules linked in: > [ 0.008964] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.0.13-200.fc29.ppc64le #1 > [ 0.009018] NIP: c000000001029ab8 LR: c000000001029aac CTR: c0000000018e0000 > [ 0.009065] REGS: c0000007f96d7900 TRAP: 0700 Tainted: G W (5.0.13-200.fc29.ppc64le) > [ 0.009119] MSR: 8000000002029033 CR: 28000222 XER: 20040000 > [ 0.009168] CFAR: c0000000001b1e28 IRQMASK: 0 > [ 0.009168] GPR00: c000000001029aac c0000007f96d7b90 c0000000015e8600 0000000000000000 > [ 0.009168] GPR04: 0000000000000001 0000000000000000 0000000000000061 646f6d61696e0d0a > [ 0.009168] GPR08: 00000007fd8f0000 0000000000000001 c0000000014c44c0 c0000007f96d76cf > [ 0.009168] GPR12: 0000000000000000 c0000000018e0000 0000000000000001 0000000000000000 > [ 0.009168] GPR16: 0000000000000000 0000000000000001 c0000007f96d7c08 c0000000016903d0 > [ 0.009168] GPR20: c0000007fffe04e8 ffffffffffffffea c000000001620164 c00000000161fe58 > [ 0.009168] GPR24: c000000000ea6c88 c0000000011151a8 00000000006000c0 c0000007f96d7c34 > [ 0.009168] GPR28: 0000000000000000 c0000000014b286c c000000001115180 c00000000161dc70 > [ 0.009558] NIP [c000000001029ab8] xics_smp_probe+0x38/0x98 > [ 0.009590] LR [c000000001029aac] xics_smp_probe+0x2c/0x98 > [ 0.009622] Call Trace: > [ 0.009639] [c0000007f96d7b90] [c000000001029aac] xics_smp_probe+0x2c/0x98 (unreliable) > [ 0.009687] [c0000007f96d7bb0] [c000000001033404] pSeries_smp_probe+0x40/0xa0 > [ 0.009734] [c0000007f96d7bd0] [c0000000010212a4] smp_prepare_cpus+0x62c/0x6ec > [ 0.009782] [c0000007f96d7cf0] [c0000000010141b8] kernel_init_freeable+0x148/0x448 > [ 0.009829] [c0000007f96d7db0] [c000000000010ba4] kernel_init+0x2c/0x148 > [ 0.009870] [c0000007f96d7e20] [c00000000000bdd4] ret_from_kernel_thread+0x5c/0x68 > [ 0.009916] Instruction dump: > [ 0.009940] 7c0802a6 60000000 7c0802a6 38800002 f8010010 f821ffe1 3c62001c e863b9a0 > [ 0.009988] 4b1882d1 60000000 7c690034 5529d97e <0b090000> 3d22001c e929b998 3ce2ff8f > > Look for xive=off during prom_init and don't ask for XIVE in this case. One > exception though: if the host only supports XIVE, we still want to boot so > we ignore xive=off. > > Similarly, have the spapr XIVE init code to looking at the interrupt mode > negociated during CAS, and ignore xive=off if the hypervisor only supports > XIVE. > > Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") > Cc: stable@vger.kernel.org # v4.20 > Reported-by: Pavithra R. Prakash > Signed-off-by: Greg Kurz > Reviewed-by: Cédric Le Goater Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/a3bf9fbdad600b1e4335dd90979f8d60 cheers