From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1D177156880 for ; Wed, 24 Apr 2024 05:35:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713936914; cv=none; b=D7SLkxki2kcINc5ZBBAP1dSCBd/IbAG0fw9Ljv0RauRdTy0brg1hCb78sSR3ehjeL/Zvowebibroy0ZyPVu5xO0KyTch2sQF2rWPmJkJH8vxcMIRDAFKMsYthOyKvc7s2sVTaW2Mly3UR4I5ohmii8knK/OrSWeMFWY892r2VIc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713936914; c=relaxed/simple; bh=Jn60dYRd1TpXyCZr+gNbLZI2wVr5L4k3MosQ5rxQ7qI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=a0MpnedCSB0fC6zblL8ytP5y0D7ZhPw95Yr2nuZhUTSlRrIUWkRF+hAske3la9vrLAot8yNkkLHlapMgRT8NxyghPjDo3yvxc4Pw+03PoOY1wJi3rNYla4+K3TgqwVkRJBBGOiHbhWxoHHgVBBli+QBlMUx7oYQwufsdiYtHcWU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=me6Gb6RE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="me6Gb6RE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCD0DC2BD11; Wed, 24 Apr 2024 05:35:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713936913; bh=Jn60dYRd1TpXyCZr+gNbLZI2wVr5L4k3MosQ5rxQ7qI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=me6Gb6REqEGYDSgYaLVysK5rTC3FApIW8/DgWMIAHN4p1u3QswSoRh8VwHmCNdEdi 0Qp4yfmWcMElMmp2jdFRidrf5pJblWD6ehNyj7NhuTtJL6NwWCa7EI/hZvfbxr3EN5 jafbO1E2767NcasRIql5YRa+uRfshrdkUjYIKwWUEXleEE8k6igrPElxn6D9JClkJN 7CdIvrfgctJqUr1rbwnX3vycp+ezdY+W/ShyfQ8bBJiHv8Ws4vsjn+lH876yefNL64 1eC10b8vRgryE9PfJZzMDsC2x7n/wHqriZRAxFCBgnXR7FKmwnSgB5iT2/U0V12trg dzgsY7rSaJVoA== Date: Tue, 23 Apr 2024 22:35:11 -0700 From: Josh Poimboeuf To: Sean Christopherson Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Daniel Sneddon , Pawan Gupta , Thomas Gleixner , Alexandre Chartre , Konrad Rzeszutek Wilk , Peter Zijlstra , Greg Kroah-Hartman , Andrew Cooper , Dave Hansen , Nikolay Borisov , KP Singh , Waiman Long , Borislav Petkov , Ingo Molnar , Stephen Rothwell , Michael Ellerman , Geert Uytterhoeven Subject: Re: [PATCH v4 2/5] cpu/speculation: Fix CPU mitigation defaults for !x86 Message-ID: <20240424053511.grt6tgt34wwpvzog@treble> References: <9d3c997264829d0e2b28718222724ae8f9e7d8b4.1713559768.git.jpoimboe@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Tue, Apr 23, 2024 at 07:10:23AM -0700, Sean Christopherson wrote: > On Fri, Apr 19, 2024, Sean Christopherson wrote: > > On Fri, Apr 19, 2024, Josh Poimboeuf wrote: > > > CPU speculative execution mitigations were inadvertently disabled on > > > non-x86 arches by the following commit: > > > > > > f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n") > > > > > > Fix it by replacing CONFIG_SPECULATION_MITIGATIONS with a new generic > > > CONFIG_CPU_MITIGATIONS option and moving the x86-specific mitigations to > > > a separate menu which depends on CONFIG_CPU_MITIGATIONS. > > > > Ah drat, I didn't check my mailbox until after Cc'ing Linus my own version[*]. > > > > I don't have a strong preference between the two, though I do think it's worth > > nothing that this will (obvioulsy) allow disabling mitigations at compile time > > on all architectures, which may or may not be desirable. > > > > [*] https://lore.kernel.org/all/20240420000556.2645001-2-seanjc@google.com > > Josh, when you get a chance, can you weigh in on my menu-preserving approach? > > I want to get this resolved asap so that we're not scrambing on Friday again :-) Yeah, yours looks good. Lemme go ack. -- Josh