From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.remote-ip=81.169.146.165 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=fail; t=1794332434; b=v4Lqx46t95+LqmttdDJ8fj0Nx2d+HROikiT7pkcq5SuApDq4TCYaWNRi1YBQIErCOUhe 6bE/aQCqe33fl7NgedW7zid3cJ4y3m5IsvPRWbvbUjrmgYoWlhsbRqjpxya+TcUe4KiKB w/V13a5ZRKJXxYOZJEpo7Lhqk17YEiQBAejp/VAeeluVqbE6pgHRrKeWXDE5pp7Uip+rX kPMbS0efC7Xv1Ky124eBQoUUvQyjat6GNR4e+GyGuAYvf6uKpWgz2K1Nn9Nvbe+TRvUP6 aMd5Gbx5/fvDNQpr9ANiBcMZJC/OfqInbnHIzP8kcwVuO6VlXN23VpYVQ3kxmdB7wWw== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794332434; h=DMARC-Filter:X-RZG-CLASS-ID:DKIM-Signature:DKIM-Signature:X-RZG-AUTH: Received:Subject:To:Cc:References:From:Organization:Message-ID:Date: X-Mailer:MIME-Version:In-Reply-To:Content-Type: Content-Transfer-Encoding; bh=TfBLrrNXwj9PDzJLXqf9MPbdj5kOF5LdyfVsHqX5orE=; b=cJx8I6gOfhsW1pQC1zGNEqBJfAt/WUiFZmedfxu4BS4qlWNImMLp82E1QXZ7KrrIZLUK R5Pc1kKM1q9D/r0AO5dVAVUoX0TdMtVDKxj79rRMXL1PliJ+k4InYNi81otH7gysWe4UY ir9ChFqxO0upjCt8Q9+4AXJ9gS2AAX41dYVHJSkbXdjE9XglWwNG6mq5W0+7bE7V2ZvtD WdJy6TrDjXS53oQGEXNN+/H8z7ogK9vyXhwIXz0e3lAbxAaauJQDHgtQbkeH9yfd5plB6 g0RVlsaGkQVcHhzUtW53TKuX3TubLRydcn141aaXdkwVA5dx2TdJzmGEroeYpQux2bQ== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=xenosoft.de; spf=none smtp.mailfrom=xenosoft.de; dkim=pass header.d=xenosoft.de header.i=@xenosoft.de header.a=rsa-sha256 header.s=strato-dkim-0002 header.b=LFB9YLC0; dkim=pass header.d=xenosoft.de header.i=@xenosoft.de header.a=ed25519-sha256 header.s=strato-dkim-0003 header.b=VWAHcmuN; arc=fail smtp.remote-ip=81.169.146.165 Received: from mo4-p01-ob.smtp.rzone.de (mo4-p01-ob.smtp.rzone.de [81.169.146.165]) (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 9FAB8606A33C for ; Tue, 10 Nov 2026 17:40:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9FAB8606A33C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xenosoft.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=xenosoft.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=xenosoft.de header.i=@xenosoft.de header.a=rsa-sha256 header.s=strato-dkim-0002 header.b=LFB9YLC0; dkim=pass header.d=xenosoft.de header.i=@xenosoft.de header.a=ed25519-sha256 header.s=strato-dkim-0003 header.b=VWAHcmuN ARC-Seal: i=1; a=rsa-sha256; t=1794332395; cv=none; d=strato.com; s=strato-dkim-0002; b=sPHXkF/RBruqZgEMLsmbH7+0xniN5TVzzvtuEe1lYfaiFdNe0+FD5t9WFO+HefaAeI fIpZ6l6SW8EQ+jWrI8uftQRiadYRDHiCEiyHh20kg12FHefwZr4xTs8kcHEzTymu4U0T J3ZfTxcrq/rKzsYD+RcIcFXWvm/ZFHpha3WSN1UKnFiSHKGG6LYwZrFC2BalKiQgEZuv 0v1iAIjeamdWb4VG1gee5tRGlXwe63AXonxbyZUPqG388WpqAL9nyaPXX1/pmvkgQELj zdiOmfMeaXD3Etn6adD7xWsipuIIv7JClB8JvG2aNuVyIevNNl8raCvQDFFsCfBWDIVF XeuQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; t=1794332395; s=strato-dkim-0002; d=strato.com; h=In-Reply-To:Date:Message-ID:From:References:Cc:To:Subject:Cc:Date: From:Subject:Sender; bh=TfBLrrNXwj9PDzJLXqf9MPbdj5kOF5LdyfVsHqX5orE=; b=m08KbpvwgsN2bx268zW9fXuyhLVGwcM8vy/gt/FUjSmK378Kc76Ui1+I9BLY1i1B0n splNLdYy0THd99k9/BJqARnKxlAY9DLvq0S4jkjLVAQAqZmhHMEYPsJaLjPDEGLI5J+B qXH0D55H4bk325VD7UFhJs/6MkOushJyrLAmkPi4dsBpaGZ7HcDRg87SzySCi7eF9aXO LPnAhEcrgS0bDup0O9s0TzcrADglfhLIuHhkdK04SXsUhP2a4bLvFJt8RaWrNLDfimnc 8k09yYR619X6mjkm7aAMjxpD+eiIVCj43G3ACaKxXV83CgJdNOkmSq5clFZdAt7dEPdD UoMA== ARC-Authentication-Results: i=1; strato.com; arc=none; dkim=none X-RZG-CLASS-ID: mo01 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1794332395; s=strato-dkim-0002; d=xenosoft.de; h=In-Reply-To:Date:Message-ID:From:References:Cc:To:Subject:Cc:Date: From:Subject:Sender; bh=TfBLrrNXwj9PDzJLXqf9MPbdj5kOF5LdyfVsHqX5orE=; b=LFB9YLC0+d82j0Crw0Cj/NzFyDCb7IJhCvq2LJZhuwu5e8e6tG9U8m7cNFBQM7+SPR Du3uvZtzkLhDWbKYc8jpMkFYwMgUbluZWu4FMO+GYaP5PhJzBlFZ6GGBdEdEoNJROIVD h+mCpBCRec+xIYWZxFbMXoFgp1XoFWFZ3sj9okIVNy9gN86wcq9TMoaydbRmPwWYJ43l e6huYo/16aYsyWWl+ELUwMLpyrwuVO/Cb6WVpZ9hqMOG1vCjlTjmS+DFQzDlunWDwRfX xB7YgOp9NLze+eeyGIhvzzlJbEKz8L9ozx26ammgrqWDQE224P76cKlgG4l9PlF1bH+M bvpw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; t=1794332395; s=strato-dkim-0003; d=xenosoft.de; h=In-Reply-To:Date:Message-ID:From:References:Cc:To:Subject:Cc:Date: From:Subject:Sender; bh=TfBLrrNXwj9PDzJLXqf9MPbdj5kOF5LdyfVsHqX5orE=; b=VWAHcmuNxt67l+OLByVVf+oFGjQtveIzuLDwfhBm1q6T8SQVIrRFp5+/mNaXrkO/4y sThiQYB6+1Kvk6HG+/Ag== X-RZG-AUTH: ":L2QefEenb+UdBJSdRCXu93KJ1bmSGnhMdmOod1DhGN0rBVhd9dFr4thIFiqT9BURIC+l5Bzg" Received: from void-ppc.a-eon.tld by smtp.strato.de (RZmta 55.6.3 DYNA|AUTH) with ESMTPSA id e825d92AAHdrhx0 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Tue, 10 Nov 2026 18:39:53 +0100 (CET) Subject: Re: [PATCH v2 0/3] KVM: PPC: BookE: Fix boot hang on preemptible kernels To: Shrikanth Hegde , maddy@linux.ibm.com, linuxppc-dev@lists.ozlabs.org Cc: 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, "R.T.Dickinson" , mad skateman , Damien Stewart , Christian Zigotzky References: <20261110053238.3794500-1-sshegde@linux.ibm.com> From: Christian Zigotzky Organization: A-EON Open Source Message-ID: <519cb2b2-5c3d-a75e-6919-d5d0784bae63@xenosoft.de> Date: Tue, 10 Nov 2026 18:39:52 +0100 X-Mailer: BrassMonkey/35.0.2 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 In-Reply-To: <20261110053238.3794500-1-sshegde@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/11/26 06:32, Shrikanth Hegde wrote: > 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 (years!). > > 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, I haven't taken the tested-by tag since patches have > changed quite a bit. > Please help in *testing* the patches again. > > v1->v2: > - Re-order to avoid preempt count dance (Narayana Murty N) > - Do only hard_irq_disable on PPC64 to avoid second warning. On PPC32 > use local_irq_disable to acheive the same. (Ritesh Harjani) > > v1: https://lore.kernel.org/all/20260928110411.844582-1-sshegde@linux.ibm.com/ > > New API ppc_hard_irq_disable could potentially be used in other places. > There is similar pattern of doing both local and hard irq disable and > likely not all callsites need both. But it is a larger effort and due to > my time limit, it will be taken up subsequently. > > Shrikanth Hegde (3): > powerpc/irq: Add ppc_hard_irq_disable() > KVM: PPC: BookE: Load FP and Altivec before enabling the interrupts > KVM: PPC: Use ppc_hard_irq_disable before guest entry > > arch/powerpc/include/asm/hw_irq.h | 17 +++++++++++++++++ > arch/powerpc/kvm/booke.c | 7 +++++-- > arch/powerpc/kvm/powerpc.c | 14 +++----------- > 3 files changed, 25 insertions(+), 13 deletions(-) > I patched the RC2 of kernel 7.4 with these three new patches and compiled it again [1]. The patched RC2 preempt kernel works with KVM HV without any problems. Tested-by: Christian Zigotzky Thanks a lot for your help! :-) [1] https://github.com/chzigotzky/kernels/releases/tag/v7.4.0-rc2-2 -- Sent with BrassMonkey 35.0.2 (https://github.com/chzigotzky/Web-Browsers-and-Suites-for-Linux-PPC/releases/tag/BrassMonkey_35.0.2)