From patchwork Wed May 15 10:05:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 1099926 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 453qvb734Xz9s9T for ; Wed, 15 May 2019 20:06:19 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=kaod.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 453qvb6589zDqSY for ; Wed, 15 May 2019 20:06:19 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=softfail (mailfrom) smtp.mailfrom=kaod.org (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=groug@kaod.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kaod.org Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 453qtN5brnzDqRK for ; Wed, 15 May 2019 20:05:13 +1000 (AEST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4F9vsi0013073 for ; Wed, 15 May 2019 06:05:09 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sgfu82ttc-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 15 May 2019 06:05:09 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 15 May 2019 11:05:03 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4FA52XK48234672 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 May 2019 10:05:02 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 73DE0A405D; Wed, 15 May 2019 10:05:02 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 27EF1A4040; Wed, 15 May 2019 10:05:02 +0000 (GMT) Received: from bahia.lan (unknown [9.145.156.103]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 15 May 2019 10:05:02 +0000 (GMT) Subject: [PATCH] powerpc/pseries: Fix xive=off command line From: Greg Kurz To: Michael Ellerman , Paul Mackerras , Benjamin Herrenschmidt Date: Wed, 15 May 2019 12:05:01 +0200 User-Agent: StGit/unknown-version MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19051510-4275-0000-0000-00000334FAC1 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051510-4276-0000-0000-000038447E0B Message-Id: <155791470178.432724.8008395673479905061.stgit@bahia.lan> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-05-15_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1034 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905150065 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+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 --- eac1e731b59e is a v4.16 commit actually but this patch only applies cleanly to v4.20 and newer. If needed I can send a backport for older versions. --- arch/powerpc/kernel/prom_init.c | 16 +++++++++++- arch/powerpc/sysdev/xive/spapr.c | 52 +++++++++++++++++++++++++++++++++++++- 2 files changed, 66 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index 523bb99d7676..c8f7eb845927 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -172,6 +172,7 @@ static unsigned long __prombss prom_tce_alloc_end; #ifdef CONFIG_PPC_PSERIES static bool __prombss prom_radix_disable; +static bool __prombss prom_xive_disable; #endif struct platform_support { @@ -808,6 +809,12 @@ static void __init early_cmdline_parse(void) } if (prom_radix_disable) prom_debug("Radix disabled from cmdline\n"); + + opt = prom_strstr(prom_cmd_line, "xive=off"); + if (opt) { + prom_xive_disable = true; + prom_debug("XIVE disabled from cmdline\n"); + } #endif /* CONFIG_PPC_PSERIES */ } @@ -1216,10 +1223,17 @@ static void __init prom_parse_xive_model(u8 val, switch (val) { case OV5_FEAT(OV5_XIVE_EITHER): /* Either Available */ prom_debug("XIVE - either mode supported\n"); - support->xive = true; + support->xive = !prom_xive_disable; break; case OV5_FEAT(OV5_XIVE_EXPLOIT): /* Only Exploitation mode */ prom_debug("XIVE - exploitation mode supported\n"); + if (prom_xive_disable) { + /* + * If we __have__ to do XIVE, we're better off ignoring + * the command line rather than not booting. + */ + prom_printf("WARNING: Ignoring cmdline option xive=off\n"); + } support->xive = true; break; case OV5_FEAT(OV5_XIVE_LEGACY): /* Only Legacy mode */ diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c index 575db3b06a6b..2e2d1b8f810f 100644 --- a/arch/powerpc/sysdev/xive/spapr.c +++ b/arch/powerpc/sysdev/xive/spapr.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -663,6 +664,55 @@ static bool xive_get_max_prio(u8 *max_prio) return true; } +static const u8 *get_vec5_feature(unsigned int index) +{ + unsigned long root, chosen; + int size; + const u8 *vec5; + + root = of_get_flat_dt_root(); + chosen = of_get_flat_dt_subnode_by_name(root, "chosen"); + if (chosen == -FDT_ERR_NOTFOUND) + return NULL; + + vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size); + if (!vec5) + return NULL; + + if (size <= index) + return NULL; + + return vec5 + index; +} + +static bool xive_spapr_disabled(void) +{ + const u8 *vec5_xive; + + vec5_xive = get_vec5_feature(OV5_INDX(OV5_XIVE_SUPPORT)); + if (vec5_xive) { + u8 val; + + val = *vec5_xive & OV5_FEAT(OV5_XIVE_SUPPORT); + switch (val) { + case OV5_FEAT(OV5_XIVE_EITHER): + case OV5_FEAT(OV5_XIVE_LEGACY): + break; + case OV5_FEAT(OV5_XIVE_EXPLOIT): + /* Hypervisor only supports XIVE */ + if (xive_cmdline_disabled) + pr_warn("WARNING: Ignoring cmdline option xive=off\n"); + return false; + default: + pr_warn("%s: Unknown xive support option: 0x%x\n", + __func__, val); + break; + } + } + + return xive_cmdline_disabled; +} + bool __init xive_spapr_init(void) { struct device_node *np; @@ -675,7 +725,7 @@ bool __init xive_spapr_init(void) const __be32 *reg; int i; - if (xive_cmdline_disabled) + if (xive_spapr_disabled()) return false; pr_devel("%s()\n", __func__);