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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 94FA2C2BD09 for ; Fri, 28 Jun 2024 12:02:43 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=I7UOV2xN; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4W9YwJ6QsZz3clT for ; Fri, 28 Jun 2024 22:02:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=I7UOV2xN; dkim-atps=neutral Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4W9YvT4d2pz3cPK for ; Fri, 28 Jun 2024 22:01:57 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1719576117; bh=WVjYDwn3UJEIGo/7AkzmjmcOPcEK3IkFmuOVjJHiGgE=; h=From:To:Subject:In-Reply-To:References:Date:From; b=I7UOV2xNBamBedgcOI9zZVKP+XOub/Y8Vc5NWgQjJ7i1t4b/6L7I/MwSUu409KFIX HxzaSAqQkXU3C6+aKRXfo+o7kyjOzryOYanrxLpQq219NNxZs+sRcG/TioX8uEIc0V FBSLT6mXRX89468d3vyDo/NWTQpJ+34bgFXq+IqE84CiIttL3PIBVBN0obrFTIaTvz EjLwdsmpE/gopyPNAk9KHhVXCDXohth5zocUQJ29gMwrWj70kpeGlEPeBb/Q0A3YgD mPmAelWCfQrWfh0gCdxlOuOC1sV4p7UJiM17Ch2z0M6v8KU3Z5NTxLj9dfPgLoAARj VCfLT8HJCbPyA== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4W9YvT0cYSz4w2K; Fri, 28 Jun 2024 22:01:56 +1000 (AEST) From: Michael Ellerman To: Sourabh Jain , Nicholas Piggin , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec In-Reply-To: <3b4b2943-49ad-4619-b195-bc416f1d1409@linux.ibm.com> References: <20240625134047.298759-1-npiggin@gmail.com> <87sex0oxym.fsf@mail.lhotse> <3b4b2943-49ad-4619-b195-bc416f1d1409@linux.ibm.com> Date: Fri, 28 Jun 2024 22:01:56 +1000 Message-ID: <87bk3ll1hn.fsf@mail.lhotse> MIME-Version: 1.0 Content-Type: text/plain 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: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Sourabh Jain writes: > On 26/06/24 14:57, Michael Ellerman wrote: >> Nicholas Piggin writes: >>> kexec on pseries disables AIL (reloc_on_exc), required for scv >>> instruction support, before other CPUs have been shut down. This means >>> they can execute scv instructions after AIL is disabled, which causes an >>> interrupt at an unexpected entry location that crashes the kernel. >>> >>> Change the kexec sequence to disable AIL after other CPUs have been >>> brought down. >>> >>> As a refresher, the real-mode scv interrupt vector is 0x17000, and the >>> fixed-location head code probably couldn't easily deal with implementing >>> such high addresses so it was just decided not to support that interrupt >>> at all. >>> >>> Reported-by: Sourabh Jain >> >> Was this reported publicly? I don't remember it. > > No, I didn't report this issue publicly. OK. It's always nice to have a public report so if someone else hits it, either at the same time, or in the future, they can search the archive and see that it's been reported. But this now counts as a public report, so I'll just point the link at this thread :) cheers