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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 1BD30C43327 for ; Fri, 26 Jun 2026 17:07:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=juJVPnk1nM/NXnz2d98pIoSDNwa75f898mQYNM3826k=; b=DoiEYVFJbK85TRsHip6Z5iw8gH urubO+9UiMdnhg0zpbbazAP/DNEVJvTpNrhjem48Mbx1eHz+2x4+fBun7bq3L5HsYyMdRBgapsmX/ BUzEMp48EN+gmQ+VzRSObsmZRTtf5j/SNCtmxSmZjoDgfLfPNYz3L/FnWIvgHzswVNC2aKcNi9S2k AHLHS1A5SBJCbiU0io7RgBmRW+QjgqPtPSNDCFjnG6BY0+Kz7Brf+3udfhP4i2+1LU75MW48ncTo1 VlGCncc2gBsaXelM84iqqWEB/z/c67FWuL5kJDjL1FGYuM2YyZRyG6ru0YiNts633ECXmxrUSYCfz elRRzaaA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wdA1S-0000000BgFF-1tnq; Fri, 26 Jun 2026 17:07:22 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wdA1N-0000000BgDz-1bir; Fri, 26 Jun 2026 17:07:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 036DB1F60; Fri, 26 Jun 2026 10:07:12 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 793AD3F632; Fri, 26 Jun 2026 10:07:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782493636; bh=ylfDgokWIdBatf69Bqo3iSYQXfGqiAjcEuPHy5u2PLE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JP49E4PS3c5WyTeeBtQ7DS3TS1dFSwX05hGVEdAiV/ydyNWiIoWTMyKGrntMHB5dI s0qam6HkCI7dSTGsU7vZFmYIBYwP04z5RiCm9QrZa0B1OI1eSswlpKSdhpyCb5TxIZ T0hMZ+udy2aE80t9jhGwoDxt47L+MGlZ1QCEtw6w= Date: Fri, 26 Jun 2026 18:07:10 +0100 From: Catalin Marinas To: Kiryl Shutsemau Cc: Will Deacon , James Morse , Mark Rutland , Marc Zyngier , Doug Anderson , Petr Mladek , Thomas Gleixner , Andrew Morton , Baoquan He , Puranjay Mohan , Usama Arif , Breno Leitao , Julien Thierry , Lecopzer Chen , Sumit Garg , kernel-team@meta.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Kiryl Shutsemau (Meta)" Subject: Re: [PATCH v4 0/4] arm64: cross-CPU NMI via SDEI Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260626_100717_457398_5EC536F5 X-CRM114-Status: GOOD ( 13.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jun 17, 2026 at 08:20:01PM +0100, Kiryl Shutsemau wrote: > - A CPU stopped by the SDEI rung is parked, not powered off via PSCI > CPU_OFF. Reaching and dumping the wedged CPU -- the point of the > series -- works, and it matches the shared stop path's own park > fallback when CPU_OFF is unavailable. The consequence is that an SMP > crash-capture kernel cannot re-online such a CPU (it stays "already > on"); the capture kernel boots and runs on the remaining CPUs. > Powering the stopped CPU off so a capture kernel can reclaim it > requires completing the SDEI event and then CPU_OFF, which hit a > firmware-specific issue still under investigation; it is left as a > follow-up and does not affect the dump's contents. Just to understand, your firmware cannot cope with a PSCI CPU_OFF from the SDEI handler? This is one of the required calls to be supported. -- Catalin