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 1B426C54E49 for ; Fri, 23 Feb 2024 10:30:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4IYo31/vu+89PjkxaRw18BvGJtWOOJ+6McEGmJOYkRY=; b=WAFrv0zoelzb5I 3UHbW100yqbLTDKHIKUOdtj6C56Lvh6Y1C9qXvtcBFkX/7riGBevaSFkxwuaGGXiLu+Siy+RTFori q2eNWIeYaSplGLmc/cLVHLB9umLX0OmJE93SPSoHwr1Mx1w47yAEEpastzZ/+YAiMoeZOGKBL6ON6 QKoE5mt8VBe3NoeJMbctpwxgRLHXmaZvKq/ig+ZLB+DxMrv2RvzY8NkbYWi9Z38y3dgbuzSGkkYGy zErMLkg8oPEDdDozL7dV+lQhscRtw/rtU1QwYOQX99MAlFGFdz8xL38egZhs6YB1mJncoE6wOnzbo jBnkGYwwfAKdBJQom1aQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rdSp7-00000008vl0-1gl4; Fri, 23 Feb 2024 10:30:33 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rdSnB-00000008v6w-08OX for kexec@lists.infradead.org; Fri, 23 Feb 2024 10:29:43 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1708684109; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rCkSqOHXuNZNZ4qVAhXnw7igAzpOyBDOC7OEqD/cJhc=; b=U11EX3Gs7FK3ddaIS5hLCrLHSqX9h8fgsM12+dEprj9QStdLmwDUXgmjR6ptTQ6s+nm5aC KQp49Cg6YVxaAjH/FggpkbntKzvEAHfW6bH19BZzDvAuGvdzB+03XUxRqSvmR2KFlIjX7S 9Gfe8CkA4zwjNMOqiV5srnkr6hVd+9ayY9O3C8Cr80aK7dmjLqlS7hfTJ3Kiz3MKioJmpV BVSQrfb1dVuIo4kNHW7DeWpx9slJcF2TTTOtc0uEfH+u41wdotKzFo8PbmsAjdMlivK7zy kO1sbtUrK1bWMfz5VVUTE1/DrhsAVFxnaShTHZvnWn6cl1vs9bvbTe9exxnfgg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1708684109; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rCkSqOHXuNZNZ4qVAhXnw7igAzpOyBDOC7OEqD/cJhc=; b=zbZmICswW00KhN+dV6Wcm66nBj+5YEQ3qEg6CAYuhnU5gj+g/sB9sxUv6UKb+ibV6/Tyl+ xLqpn93b+a658eBw== To: "Kirill A. Shutemov" , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Baoquan He , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [PATCHv7 13/16] x86/acpi: Do not attempt to bring up secondary CPUs in kexec case In-Reply-To: <20240212104448.2589568-14-kirill.shutemov@linux.intel.com> References: <20240212104448.2589568-1-kirill.shutemov@linux.intel.com> <20240212104448.2589568-14-kirill.shutemov@linux.intel.com> Date: Fri, 23 Feb 2024 11:28:28 +0100 Message-ID: <87msrrcw4z.ffs@tglx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240223_022833_421681_9B91ED68 X-CRM114-Status: GOOD ( 11.07 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Mon, Feb 12 2024 at 12:44, Kirill A. Shutemov wrote: > ACPI MADT doesn't allow to offline a CPU after it was onlined. This > limits kexec: the second kernel won't be able to use more than one CPU. > > To prevent a kexec kernel from onlining secondary CPUs invalidate the > mailbox address in the ACPI MADT wakeup structure which prevents a > kexec kernel to use it. > > This is safe as the booting kernel has the mailbox address cached > already and acpi_wakeup_cpu() uses the cached value to bring up the > secondary CPUs. > > Note: This is a Linux specific convention and not covered by the > ACPI specification. > > Signed-off-by: Kirill A. Shutemov > Reviewed-by: Kai Huang > Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Thomas Gleixner _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec