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Mon, 28 Sep 2026 11:04:20 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.ibm.com.com (unknown [9.124.213.68]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 28 Sep 2026 11:04:20 +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 Subject: [PATCH 0/2] KVM: PPC: BookE: Fix boot hang on preemptible kernels Date: Mon, 28 Sep 2026 16:34:09 +0530 Message-ID: <20260928110411.844582-1-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-ORIG-GUID: 4d7Bwx2TXR8wB1sgdDmCh-WGPNJQzTOG X-Proofpoint-GUID: H8XYzw1x7xxTf_bByvrH_cIocGc6sg-X X-Proofpoint-Spam-Info: AW1haW4tMjYwOTI4MDA0MiBTYWx0ZWRfXwdZPzwPoV1Um PO+mUVn2HH3UMY3hFYlo8L7hNrbtLWRDhICdwtpvSD2gfdHpWGhgG0uat1yIyR5QvL8YvOQzvVk q45kwMKZd/ubTQ3i9iJvhdNd8JRY3Tg= X-Authority-Analysis: v=2.4 cv=Vv62kO2n c=1 sm=1 tr=0 ts=6aba49bd cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=VdqzKS8jKosA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=VwQbUJbxAAAA:8 a=ZFN0TsNAI0be_PaQA-wA:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTI4MDA0MiBTYWx0ZWRfXxyPyfmW1GiFQ oWw/NSp3Op7VeOlejRY2oVsAsTykoD8kijKRf9lu4B3Nb4Xpe6QxZVD2TraSpqCBO7rKw7UFgHb qnhWR56b06Hhg+L9EwZO2u3bJ2kj9L+sBaIxBryKzYPU3gT+RGxTLdNYk3S7yb9AZSzq4nn00nP IymfYHqIUqrVCvJdww+hRyEBQrvhN5s+O3L1kmJolKbdekvm0OuyYid6iROdY3Y6BxVrdQIehWW pBjiPi3cTG2pxrCN4bY2xdxeyHWgnhlX/0uCTef4OLpao/8q9+xRjoLJiRACF3fgOi6fbPPCEjP dSoAEt+s6ghnXiRXvKmWaTMZUh9Q2JDeR0a2EE6Cs4MBOMrRIE6Q6AyV3hXQTwXOYIpvM8e+K0J 3NjL47kXzJXJYDZxEpUq55p8mjEcGbc0CzFKiKusA/7cnfJiVGLX8/CWiLAORBBcg0PCXRqFkpz SZXSCShyydMCMnbxjIA== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-28_02,2026-09-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 spamscore=0 phishscore=0 bulkscore=0 adultscore=0 priorityscore=1501 malwarescore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609280042 Christian Zigotzky had reported that preemptible kernels don't boot on his FSL Cyrus+ board. The board freezes on running either full/lazy preemption and has been an issue for a while now. https://lore.kernel.org/all/b897b0fd-90f2-4215-bcd4-3714e497d773@xenosoft.de/#t After 7.0, there is only preempt=full/lazy which removed the preempt=none/voluntary workaround used to mask the issue. There was challenge is getting the console logs which made the fixes difficult since one couldn't know where the issue is. Thanks to Michal for helping in getting the logs. That pointed at few places where the issue could be. This series is an attempt at fixing those. Christian, KVM team, Please *test* the patches. Shrikanth Hegde (2): KVM: PPC: BookE: Disable preemption before loading guest FP and Altivec KVM: PPC: Replay pending interrupts before entering the guest arch/powerpc/kvm/booke.c | 9 ++++++++- arch/powerpc/kvm/powerpc.c | 13 +++++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) -- 2.52.0