From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=148.163.158.5 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794288803; b=hxZp2yTdlcfpw8hPVPJwwa9XVmceA99qPZiYKI98OCuuLHoPWo1h2AKXjRmeJCNlSdYX DLgMBIPqtFby9oksWyh7iht4cwTp55o64ykkQ2OxayuN5VSi5fzoweUa6ws6LEl9yqkp9 VOYFHp0mRQ2Folj7SoHoYmwXclyPQEljyjEA/xhUHe7WB/kSp9ujExNs89GanPcMlSeLD KkM4vhW0G3cBYGndY6QY7A+qC0/4/tWDprmcRPLyNhNoSLpMQcuh9UyRdzIkgbIE4Ccy/ tHhmLLDr/oK+aJaHxwqtV3OeAxD3/emNfMxIkzzIyqwjKWCtD1Ra3appYcvbakmQMvw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794288803; h=DMARC-Filter:Received:DKIM-Signature:Received:Received:Received: Received:Received:Received:Received:From:To:Cc:Subject:Date: Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-TM-AS-GCONF:X-Proofpoint-Reinject: X-Authority-Analysis:X-Proofpoint-Spam-Details-Enc: X-Proofpoint-Spam-Info:X-Proofpoint-ORIG-GUID:X-Proofpoint-GUID: X-Proofpoint-Virus-Version:X-Proofpoint-Spam-Details; bh=XURghLDdbpBHSseZCMICptPJ+mhtNx8zOLlVbrChsOg=; b=y2daZ/1K3IkRqsTVzq9SACDZlAIf9wgVcs5FW6/Awa/XzroY+sBsj3wRL1gwj2pVCqWw 0g1svzNJBVMePit/5KuBNYvtkDlYWLDku69HXIdGYu+k2Z3k3/ND+lB/sWwOtJaQVUVqe Ju+mHMSyljteAO9vFBIlEewrW2cfZHyyxrctrFmV4vBBDcpi862qiLRp0fs+++vyH9T3/ FIb4q7AC7IpuERX0c2ip2mYLevBX85EkC3ysWhujEFmf1cfZMZS7HFKqDj8FEppt49Xqy QbF4K764qR2iLWSsDVpIMLkGHbAjz1D7RvhKDSP/1SkopqkSe+kgGQzsZcNxMsIoFxg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b="HYXP/UhQ"; arc=none smtp.remote-ip=148.163.158.5 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 404EC606A321 for ; Tue, 10 Nov 2026 05:33:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 404EC606A321 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=HYXP/UhQ Received: from pps.filterd (m0356516.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 6AA51rlk1369037; Tue, 10 Nov 2026 05:33:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=XURghLDdbpBHSseZC MICptPJ+mhtNx8zOLlVbrChsOg=; b=HYXP/UhQ24guwxYdSY29afs82ONL7hlbZ K8WYv6GUqDOj7b8Pw6lL4BK3+fpOhPtk61ZSTS/KwheLco7t22muES6RisNM2YC9 2yIDjrzWaADczM3I8fMOYp085jKF6hXECsgEr6efO4A65CbIUOsoX2ngsnzIpO4Q MQW/kuBtTXsFS+xnwBEEisyJwATtQeGWFi4FbZ81QSUsrVWXWXwUqcinDcEs30sJ F/p2lymcj4R34iC7eumrTPaA/NSbRLuyA+tdzILzZTxjDlDW3QlFu3A8jJWfeuaF csNi2P/8w2C3xm+8EflWG/tnGWXmhSjYu1k/gwAIQNZXjwMcEiQ1g== Received: from ppma13.dal12v.mail.ibm.com (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4hssdkkgjw-1 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 10 Nov 2026 05:33:07 +0000 (GMT) Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.18.1.11/8.18.1.11) with ESMTP id 6AA4K28j099402; Tue, 10 Nov 2026 05:33:06 GMT Received: from smtprelay07.fra02v.mail.ibm.com ([9.218.2.229]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4htghg50sg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Nov 2026 05:33:06 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay07.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 6AA5X1IL29032788 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Nov 2026 05:33:01 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C0D4520043; Tue, 10 Nov 2026 05:33:01 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C15C720040; Tue, 10 Nov 2026 05:32:57 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.ibm.com.com (unknown [9.39.31.82]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 10 Nov 2026 05:32:57 +0000 (GMT) From: Shrikanth Hegde To: maddy@linux.ibm.com, linuxppc-dev@lists.ozlabs.org, chzigotzky@xenosoft.de Cc: sshegde@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, linux-kernel@vger.kernel.org, msuchanek@suse.de, ritesh.list@gmail.com, harshpb@linux.ibm.com, gautam@linux.ibm.com, amachhiw@linux.ibm.com, venkat88@linux.ibm.com, nnmlinux@linux.ibm.com, mkchauras@gmail.com Subject: [PATCH v2 3/3] KVM: PPC: Use ppc_hard_irq_disable before guest entry Date: Tue, 10 Nov 2026 11:02:38 +0530 Message-ID: <20261110053238.3794500-4-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261110053238.3794500-1-sshegde@linux.ibm.com> References: <20261110053238.3794500-1-sshegde@linux.ibm.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Authority-Analysis: v=2.4 cv=POqaavqC c=1 sm=1 tr=0 ts=6af2ac93 cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=zJRp6_cAMcgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=SkEQ8EbvhdlHpgZ8pF0A:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYxMTEwMDAyMCBTYWx0ZWRfXzQSbEXySvIvA DGtUOepxHoORcdCIrpm1A6NXVxaocySZn1tip7FVr8XBM/d07msxC2u2HHKY3P0LH1i736zgMxn 95lR+yseAtLFN8zCkfN0R8hxvNevsR1gD651alpzN27GL2uuzbsVlteE6VS0lfkTBezFiUbPHDq 0WR32/u7D09XQecqCOfV8Up28dAycOkt30JrbYnrDYXGmTyKWYpTmo8nJEwppZkDSM0BLqZEU5z 1oOlnQhL8FSHpKhjI/q1fP3OSLD+LDHhgoo5IsIs8sPuwINb7PUhriNY6qpGWiyRSmHJ723tIYQ 2VuT5boqsxmgtOxTHCKuVO1qse/XwJ2MMyxgot1PKWkC3o5s/xU7FJ3x66UDIDsxm+FramkU/sH J8X6jvk/vM2SylxOtIz0pQ5knuoP6cAEHt8vBmWJqHNvK0wxvJ9vLIh4wc4K5Nsws/O1gOrRbmU els2pjxVPlQcKAU0qfw== X-Proofpoint-Spam-Info: AW1haW4tMjYxMTEwMDAyMCBTYWx0ZWRfXzkOQGFQHPjGh XYZXHb6hkwmnxQw3xsAdE3Nr3Rny6eFdRSCQFIfSocR+wjImFrOODBdjAyqirMiSIAWJD5yoczC Is/QBoNB2V+fF7NywUOWtx5fQL2gfsQ= X-Proofpoint-ORIG-GUID: 5ysNvkqFxTrtpuScNsllgi5GhS4SY-_q X-Proofpoint-GUID: 1ojaqWB2etFZNsH3pknDmaRKMfLgrVtj X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.138,FMLib:17.12.100.49 definitions=2026-11-10_02,2026-11-06_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 bulkscore=0 impostorscore=0 malwarescore=0 phishscore=0 lowpriorityscore=0 suspectscore=0 adultscore=0 spamscore=0 clxscore=1015 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2611040001 definitions=main-2611100020 After applying preempt disable patch, i.e PATCH 2/3, Christian reported a subsequent warning stopping his board to boot properly. WARNING: at .kvmppc_fix_ee_before_entry+0x10/0x28, CPU#0: qemu-system-ppc/4667 CPU: 0 UID: 1000 PID: 4667 Comm: qemu-system-ppc Tainted: G W 7.3.0-rc4-2-powerpc64-smp #1 PREEMPT Tainted: [W]=WARN Hardware name: varisys,CYRUS5040 e5500 0x80240012 CoreNet Generic NIP [c00000000005dc3c] .kvmppc_fix_ee_before_entry+0x10/0x28 LR [c00000000005f298] .kvmppc_handle_exit+0x5b4/0x5e8 Call Trace: [c000000086587780] [c00000000005ee10] .kvmppc_handle_exit+0x12c/0x5e8 (unreliable) [c000000086587830] [c000000000062068] .kvmppc_resume_host+0xb8/0x10c It triggers below warning... static inline void kvmppc_fix_ee_before_entry(void) { trace_hardirqs_on(); /* * To avoid races, the caller must have gone directly from having * interrupts fully-enabled to hard-disabled. */ WARN_ON(local_paca->irq_happened != PACA_IRQ_HARD_DIS); This happens since kvmppc_prepare_to_enter does first local_irq_disable followed by hard_irq_disable. This leaves a small window where interrupt may occur and it could set the irq pending bit in PACA. That local_irq_disable was necessary for PPC32 to track the lockdep state etc. On PPC64 hard_irq_disable is good enough. There is no need to do both. Use the new irq api to do the necessary one. Fixes: 12013e3d4695 ("KVM: powerpc: Use generic xfer to guest work function") Reported-by: Christian Zigotzky Closes: https://lore.kernel.org/all/b8f82519-9ae5-c247-e020-e79c627e57df@xenosoft.de/ Signed-off-by: Shrikanth Hegde --- arch/powerpc/kvm/powerpc.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 9194cf492d1c..4ee3d7bfe917 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -81,13 +81,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) int r; WARN_ON(irqs_disabled()); - /* - * local_irq_disable() first: on 32-bit, hard_irq_disable() alone is a - * raw MSR[EE] clear that bypasses the lockdep/irq-tracing state, and - * the xfer_to_guest_mode helpers assert IRQs are seen as disabled. - */ - local_irq_disable(); - hard_irq_disable(); + ppc_hard_irq_disable(); while (true) { xfer_to_guest_mode_prepare(); @@ -101,8 +95,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) */ local_irq_enable(); r = kvm_xfer_to_guest_mode_handle_work(vcpu); - local_irq_disable(); - hard_irq_disable(); + ppc_hard_irq_disable(); if (r) { /* * The generic helper does not set the exit @@ -134,8 +127,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) local_irq_enable(); trace_kvm_check_requests(vcpu); r = kvmppc_core_check_requests(vcpu); - local_irq_disable(); - hard_irq_disable(); + ppc_hard_irq_disable(); if (r > 0) continue; break; -- 2.52.0