From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.skyhub.de ([5.9.137.197]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iNBIl-0005R9-1w for kexec@lists.infradead.org; Wed, 23 Oct 2019 07:43:28 +0000 Date: Wed, 23 Oct 2019 09:43:16 +0200 From: Borislav Petkov Subject: Re: [PATCH 1/3 v4] x86/kdump: always reserve the low 1MiB when the crashkernel option is specified Message-ID: <20191023074316.GA16060@zn.tnic> References: <20191017094347.20327-1-lijiang@redhat.com> <20191017094347.20327-2-lijiang@redhat.com> <20191022083015.GB31700@zn.tnic> <0e657965-6f97-84ce-e51d-42d4978c4d88@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <0e657965-6f97-84ce-e51d-42d4978c4d88@redhat.com> 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+dwmw2=infradead.org@lists.infradead.org To: lijiang Cc: jgross@suse.com, Thomas.Lendacky@amd.com, bhe@redhat.com, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, mingo@redhat.com, ebiederm@xmission.com, hpa@zytor.com, tglx@linutronix.de, dyoung@redhat.com, vgoyal@redhat.com On Wed, Oct 23, 2019 at 01:23:33PM +0800, lijiang wrote: > Kdump kernel will reuse the first 640k region because the real mode > trampoline has to work in this area. When the vmcore is dumped, the > old memory in this area may be accessed, therefore, kernel has to > copy the contents of the first 640k area to a backup region so that > kdump kernel can read the old memory from the backup area of the > first 640k area, which is done in the purgatory(). That sounds better. :) -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec