From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2B0B7606A32F for ; Wed, 4 Nov 2026 12:19:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=zAmj/+1T; dkim=fail reason="signature verification failed" (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=b4/4svk5 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: MIME-Version:Message-ID:Date:References:In-Reply-To:Subject:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=qimrld6Qquu3/RsDXXsu/ihBQCwzuzT0jn+pZL1CadM=; b=zAmj/+1Tr2eG9pLNkT720/olHb YpzaQBbJLX/Dz8opoqgKKXiat1+fym4pE/6ea16E4IzL4RTRLw/ZDAoGSDhqsOlsU1DzNH4FV/e3y JOhjqY4nOKt1IfBiXs9909h6HMGj1hKj5I4/dK9qO1uD+MSH3Iz+m4MUaEWM5tJxBPmefm1F04bLa bx3oAtA8GLi7uQKbd1vTCql3cUaEvONt0GLm0tV9TgAXK0F1j1l30bYCNa278SHlaXUyn17+ii/6O KywHoJ3AL/aGijHhNwj92BP9oIReTOzYE8KKBF3mEES/bUDLykUr4CZduUm/awsRpUcxa5B44oyAa 8IgLr7Vw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOZxe-00000005Ht8-363I; Wed, 04 Nov 2026 12:19:26 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOZxe-00000005Hsa-0nIP for kexec@lists.infradead.org; Wed, 04 Nov 2026 12:19:26 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 82D4D60F0E; Wed, 4 Nov 2026 12:19:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1B771F0093A; Wed, 4 Nov 2026 12:19:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793794765; bh=qimrld6Qquu3/RsDXXsu/ihBQCwzuzT0jn+pZL1CadM=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=b4/4svk5xILGPqtP0/hwSWfdCQyIEn7TvGLMRqs6SVM2qgtnJStNRGARXPHXsGO/W JbY1D+VPYxoXvMZmIlWgfmJ3yVe14wVT6w08BHZTT4TgPKvw/xJlozDoibhyjndx5x z6/QCycXlGIj4lV7LBOdScLxYtYkgITbtLogDDXqe8DG5AMY7YzqQCdY4pGVg7g77k z/L8LNVlOQn9lueTtR6Dxl3fqSQa5pLTzmcN+FTmzmE3uDIAmpHRv/xNTC3PE6CQ6w CPexOQidh7O5eMEfOFfg8ShJFNeW13SLdMLDCd0GA+SVTueP6vY/QYGWfRBvh9XvTx byUQEBEzPkFxA== From: Pratyush Yadav To: "Jose A. Perez de Azpillaga" Subject: Re: [RFC PATCH 0/2] memblock: keep reserve_mem regions out of KHO bootmem In-Reply-To: <70686061-787c-4c99-ba5b-ff982c8cc2ad@gmail.com> (Jose A. Perez de Azpillaga's message of "Wed, 4 Nov 2026 11:50:02 +0100") References: <20261021211058.83483-1-azpijr@gmail.com> <2vxzqzhhg8l3.fsf@kernel.org> <32dd1f28-db55-4674-99bc-74d9d3ab25db@gmail.com> <70686061-787c-4c99-ba5b-ff982c8cc2ad@gmail.com> Date: Wed, 04 Nov 2026 13:19:21 +0100 Message-ID: <2vxzfqxglrg6.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tony Luck , Pasha Tatashin , linux-mm@kvack.org, Kees Cook , Changyuan Lyu , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Alexander Graf , Pratyush Yadav , Andrew Morton , Mike Rapoport Sender: "kexec" X-Spam-Status: No, score=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Wed, Nov 04 2026, Jose A. Perez de Azpillaga wrote: > On 10/22/26 10:16 PM, Jose A. Perez de Azpillaga wrote: >> On 10/22/26 3:37 PM, Pratyush Yadav wrote: >>> On Wed, Oct 21 2026, Jose A. Perez de Azpillaga wrote: >>> >>>> On a KHO boot, a reserve_mem= region that can't be revived (new name, >>>> size or alignment) can be allocated from KHO bootmem, which the next >>>> kernel boots out of. With CONFIG_KEXEC_HANDOVER_DEBUG preserving it >>>> fails; without it, the next kernel's memmap ends up on top of it. >>> What's your use-case? Why are you adding new reserve_mem regions after >>> cold boot? I'd rather avoid making purely theoretical fixes. >> >> I don't have one, I found it through the TODO. a different reserve_mem= >> in the cmdline passed to kexec is enough to hit it. If there was a use case, I wouldn't mind fixing it. But I'd rather not add code we don't have a use case for. >> >> if it isn't meant to work across a live update, would you rather have >> reserve_mem() fail on KHO boot when it can't revive the region? This sounds good I think. >> > > ping, I can send a v2 either way. -- Regards, Pratyush Yadav