From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A866C377A93; Mon, 28 Sep 2026 18:07:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790618826; cv=none; b=RAuQwHq/fXOjLUdU03xdR9QjRFojvW7bxLYIr3CEMZlaYu4Oh9L3K3CrBrXlXczhZ2QAkIxfLHqdX5kPdyu3w7QyC0b0O2x7yM4tnk9Lom2cud9c0Wkpk0KqIe8FavRmoMtQiXAcyLZ/3gulRQOvE0KlFesS9hb6qRIcSRT17PA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790618826; c=relaxed/simple; bh=aXEt8cLj5MZO0I73asHe3zofPVNAzMphdpTAK0N6FfY=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=X5WnPkRUmCkG0gV+NA+F4PKpQ6UIe3nLN3Kxm//CG8DNXcwtr6yyUzqblPS6kO7EH4QEATrm4W53nv+N1PSha3czFb+ueFAqoVi2EoW1frqVV6NbvqMi3fwQonoSXllK6YOng8kV9WX7vUFow9XWNmWaANpubITFV7u4mmDaCBg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VkdDllWB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VkdDllWB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99F9E1F00893; Mon, 28 Sep 2026 18:07:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790618823; bh=aXEt8cLj5MZO0I73asHe3zofPVNAzMphdpTAK0N6FfY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=VkdDllWBAWV5FGuXwvbjEPRrpIDNW0dE7ueXGI1WvWp/AW/N7EAHBRQDMLs2+H3nz pLEKPGak1yaX9UVq9Fb1ucxNAhmv6RWC70uuRxMLoWv6SR2MvvK3A5DtgZ6u97b+A3 xQtUpOQCtgBAySTeKXC1iLN8suUD9vmVagzo41ghn1qN/UGn5ubVotTTdDczQLk4gS 4K8YIEQOask3UeRdr8cFTjBIok+hbWq/Fb567PzFNDVn/hhYv0r2cv5Hzs+d0CRxoO LwTagIm3x2qKu+gV6bbSJY9txsQB9ar07NT+kGal5ajgx0Hveq3co6x4xFXdGLYrEK zAwMIRi9TF9Ug== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 4/6] x86/vmware: Add a bounded pre-kdump log sender Reply-To: sashiko-reviews@lists.linux.dev To: "Baoquan He" , "Dave Young" , "Zack Rusin" , "Pratyush Yadav" , "Mike Rapoport" , "Pasha Tatashin" , "Petr Mladek" , "Andrew Morton" Cc: bcm-kernel-feedback-list@broadcom.com, "Thomas Gleixner" , "Brennan Lamoreaux" , "Ian Forbes" , "Michael Kelley" , "Steven Rostedt" , "Jonathan Corbet" , "Michael S. Tsirkin" , "Kees Cook" , "Randy Dunlap" , "Ajay Kaher" , "Maaz Mombasawala" , "Joel Granados" , "Bo Gan" , virtualization@lists.linux.dev, "John Ogness" , "Sergey Senozhatsky" , "Guilherme G. Piccoli" , kexec@lists.infradead.org, "Alexey Makhalov" , "Ingo Molnar" , "Borislav Petkov" , x86@kernel.org, "Shuah Khan" , "Stephen Brennan" , linux-doc@vger.kernel.org, "Eugenio Perez" , "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Dave Hansen" In-Reply-To: References: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 28 Sep 2026 18:07:01 +0000 Message-Id: <20260928180701.99F9E1F00893@smtp.kernel.org> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: > Preserve the newest kernel log tail in the host's vmware.log, which can > outlive a guest with no working userspace or persistent storage. >=20 > Allocate an 8 KiB buffer during early init and register on > panic_pre_kdump_list. A 4 KiB buffer can omit useful stack-trace > context. Use a fixed byte budget so transfer work does not scale > with PAGE_SIZE. >=20 > Copy the newest records, prefix them with "log ", and send one RPC over > the low-bandwidth register interface. Bound the transfer to 8 KiB and > at most three checkpoint attempts; zero-fill a partial payload word and > close the channel after every successful open. >=20 > The callback allocates nothing and emits no printk messages. Enable it > for ordinary guests, leaving encrypted guests disabled until explicitly > enabled by the sysctl. Skip initialization without printk support, and > leave logging disabled after allocation or registration failure. >=20 > Suggested-by: Michael Kelley > Link: https://lore.kernel.org/r/SN6PR02MB41574A11D309A0530C63E0FED4842@SN= 6PR02MB4157.namprd02.prod.outlook.com > Link: https://lore.kernel.org/r/20260309235250.2611115-3-alexey.makhalov@= broadcom.com > Co-developed-by: Bo Gan > Signed-off-by: Bo Gan > Co-developed-by: Alexey Makhalov > Signed-off-by: Alexey Makhalov > Signed-off-by: Zack Rusin Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/cover.1790014793.gi= t.zack.rusin@broadcom.com?part=3D4 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 45944CA5FA3 for ; Mon, 28 Sep 2026 18:07:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:Reply-To: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Message-Id:Date:Content-Transfer-Encoding:Content-Type:References:In-Reply-To :To:Subject:From:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=aXEt8cLj5MZO0I73asHe3zofPVNAzMphdpTAK0N6FfY=; b=Y+fCLcqHU2jflr6vy0lv1DaYG6 /FamY94Qxhkg4Qj+ykygp7peRaX/IprqwO2ofjimby7YH66Kiott9eJu4QzH0djWYHLNrcrIcg7pM /0fGM+Z3whK2KliYZy5YFs9g+z8gaKep7qUrQHtXWEUqdnoMRSJyCpa1gujCv0NRWIjluz40hOaHp y/C7NfuHXI62LMmQquI5ALHw9BzCM554qePc2S4FHc9L4QE08rbMtvS9zAli25NzsiMzfIso+Ozxb X35SwMVvcKrSN8ZBrxvPi1DeqryIfBQyCBDsagfwevn5LxA3YSsjC0QhqZtLeU0ieiwHUbnWZ4K3P 0wAarlYg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBFkn-00000001Gwp-18Cb; Mon, 28 Sep 2026 18:07:05 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBFkl-00000001Gwa-3i4Q for kexec@lists.infradead.org; Mon, 28 Sep 2026 18:07:03 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 9F30F437E4; Mon, 28 Sep 2026 18:07:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99F9E1F00893; Mon, 28 Sep 2026 18:07:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790618823; bh=aXEt8cLj5MZO0I73asHe3zofPVNAzMphdpTAK0N6FfY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=VkdDllWBAWV5FGuXwvbjEPRrpIDNW0dE7ueXGI1WvWp/AW/N7EAHBRQDMLs2+H3nz pLEKPGak1yaX9UVq9Fb1ucxNAhmv6RWC70uuRxMLoWv6SR2MvvK3A5DtgZ6u97b+A3 xQtUpOQCtgBAySTeKXC1iLN8suUD9vmVagzo41ghn1qN/UGn5ubVotTTdDczQLk4gS 4K8YIEQOask3UeRdr8cFTjBIok+hbWq/Fb567PzFNDVn/hhYv0r2cv5Hzs+d0CRxoO LwTagIm3x2qKu+gV6bbSJY9txsQB9ar07NT+kGal5ajgx0Hveq3co6x4xFXdGLYrEK zAwMIRi9TF9Ug== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 4/6] x86/vmware: Add a bounded pre-kdump log sender To: "Baoquan He" , "Dave Young" , "Zack Rusin" , "Pratyush Yadav" , "Mike Rapoport" , "Pasha Tatashin" , "Petr Mladek" , "Andrew Morton" In-Reply-To: References: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 28 Sep 2026 18:07:01 +0000 Message-Id: <20260928180701.99F9E1F00893@smtp.kernel.org> 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: , Reply-To: sashiko-reviews@lists.linux.dev Cc: linux-doc@vger.kernel.org, "Michael S. Tsirkin" , Kees Cook , Dave Hansen , Stephen Brennan , Bo Gan , "H. Peter Anvin" , Jonathan Corbet , Brennan Lamoreaux , x86@kernel.org, Joel Granados , Alexey Makhalov , Eugenio Perez , Ingo Molnar , bcm-kernel-feedback-list@broadcom.com, Ajay Kaher , John Ogness , virtualization@lists.linux.dev, Steven Rostedt , Maaz Mombasawala , Borislav Petkov , Shuah Khan , Michael Kelley , Randy Dunlap , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Ian Forbes , Sergey Senozhatsky , Thomas Gleixner Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org > Preserve the newest kernel log tail in the host's vmware.log, which can > outlive a guest with no working userspace or persistent storage. >=20 > Allocate an 8 KiB buffer during early init and register on > panic_pre_kdump_list. A 4 KiB buffer can omit useful stack-trace > context. Use a fixed byte budget so transfer work does not scale > with PAGE_SIZE. >=20 > Copy the newest records, prefix them with "log ", and send one RPC over > the low-bandwidth register interface. Bound the transfer to 8 KiB and > at most three checkpoint attempts; zero-fill a partial payload word and > close the channel after every successful open. >=20 > The callback allocates nothing and emits no printk messages. Enable it > for ordinary guests, leaving encrypted guests disabled until explicitly > enabled by the sysctl. Skip initialization without printk support, and > leave logging disabled after allocation or registration failure. >=20 > Suggested-by: Michael Kelley > Link: https://lore.kernel.org/r/SN6PR02MB41574A11D309A0530C63E0FED4842@SN= 6PR02MB4157.namprd02.prod.outlook.com > Link: https://lore.kernel.org/r/20260309235250.2611115-3-alexey.makhalov@= broadcom.com > Co-developed-by: Bo Gan > Signed-off-by: Bo Gan > Co-developed-by: Alexey Makhalov > Signed-off-by: Alexey Makhalov > Signed-off-by: Zack Rusin Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/cover.1790014793.gi= t.zack.rusin@broadcom.com?part=3D4