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 06A45C433F5 for ; Wed, 16 Mar 2022 15:42:23 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7yDX4nfdyS3PXbeVhDHM1XXv/51WbIHFpX7K5tzd9ME=; b=fa7LtXlRH8Kk0cDGzMFJzydSC3 1jQdm4l4RIwqCb3yEs/W6/hcCmVOwpgWO9Pn5g3lHcIbyTbHFb4ZUBQYp48XDwsKaXqgqtVUJfqNF Of9XAVspcQhx9ngqeQS0Oq9AqF+5dU/BX50n4Iv1Qi9+NG8sZXaV9eafuBqvzjp2qqqhb2U4OMrTO kYZFcaMsU13w4ITfAb3VCNXil2daAhvvsSyuTTV3wYfjty4fwfqzuqDIsMJITWlpW1vD19FTnhxOA A4pQWa2UfiqcVkhqGoNgEtyOHZGaotP0cBofqVJ+EJZLQdprGlHD37+C8M1eFiBHDB7EnUKPpDsAl CVmHB51w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUVm2-00Dd0r-Ut; Wed, 16 Mar 2022 15:41:19 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUVly-00DczW-43 for linux-arm-kernel@lists.infradead.org; Wed, 16 Mar 2022 15:41:15 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B1A45B81C17; Wed, 16 Mar 2022 15:41:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDED9C340E9; Wed, 16 Mar 2022 15:41:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647445271; bh=fGlxVPOqx7AWOT3JY9X9MOlp4HEsWoCwI1MuXI2ST8U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JYpefBRr/EeoPTiDhHMNP9czSh83o/H1eJ+HF+AtGxXhBw5YtgFL6ulKHhtuNyNqn IuVYrpWgz+E+Tl1f9LJNsS+5gKk8PekxIhASqKBumXCiiiRpP+Ww/IxMQKuIdk4HL6 EQprNezXL4o89zFvZt6jrfGZhUnkEjI/zlHlqzFqqiaJs7Da1lby3muw3MY4/OyIpv UhY05ibHDfHdHMmZESzXo4kLMkBjEKo/wreqnemevjoKnUZELcA6xYgtyAAdkgUso8 Ji5ZqUdh1QnxzvXPSTnHzGocqti1DCT3QfyoFpk9gNOqIXGsB4ilXk5i2o0rKaIKBV yfvYEN+h0awdQ== Date: Wed, 16 Mar 2022 11:41:07 -0400 From: Sasha Levin To: James Morse Cc: stable@vger.kernel.org, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org Subject: Re: [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels Message-ID: References: <20220315182415.3900464-1-james.morse@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220315182415.3900464-1-james.morse@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220316_084114_344317_644C01E6 X-CRM114-Status: GOOD ( 15.01 ) 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Mar 15, 2022 at 06:23:53PM +0000, James Morse wrote: >Hi Greg, > >Here is the state of the current v5.4 backport. Now that the 32bit >code has been merged, it doesn't conflict when KVM's shared 32bit/64bit >code needs to use these constants. > >I've fixed the two issues that were reported against the v5.10 backport. > >I had a go at bringing all the pre-requisites in to add proton-pack.c >to v5.4. Its currently 39 patches: >https://git.gitlab.arm.com/linux-arm/linux-jm.git /bhb/alternative_backport/UNTESTED/v5.4.183 >(or for web browsers: >https://gitlab.arm.com/linux-arm/linux-jm/-/commits/bhb/alternative_backport/UNTESTED/v5.4.183/ >) I've queued it up. >I've not managed to bring b881cdce77b4 "KVM: arm64: Allocate hyp vectors >statically" in, as that depends on the hypervisor's per-cpu support. Its >this patch that means those 'smccc_wa' templates are needed. >I estimate it would be 60 patches in total if we go this way, I don't >think its a good idea: >All this still has to work around 541ad0150ca4 ("arm: Remove 32bit KVM >host support") and 9ed24f4b712b ("KVM: arm64: Move virt/kvm/arm to >arch/arm64") being missing. >I think this approach creates more problems than it solves as the >files have to be in different places because of 32bit. It also creates >a significantly larger testing problem: I'm not looking forward to >working out how to test KVM guest migration over the variant-4 KVM ABI >changes in 29e8910a566a. I think that the workaround you mention later on for this issue makes sense cost/benefit-wise. >This version of the backport still adds the mitigation management code >to cpu_errata.c, because that is where this stuff lived in v5.4. > >If you prefer, I can try adding proton-pack.c as a new empty file. >I think this would only confuse matters as the line-numbers would >never match, and there is an interaction with the spectre-v2 mitigations >that live in cpu_errata.c. > >There is one patch not present in mainline 'KVM: arm64: Add templtes for >BHB mitigation sequences'. Thank you! -- Thanks, Sasha _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel