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 D0DE637104D; Mon, 23 Feb 2026 22:14:48 +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=1771884888; cv=none; b=kqGASqSfS4m9KqLf60FPiVFQnJ/Nxn4mAwjvSWC6Luihg//1kWMeo31pyvO3GREZBcH4pNb+mGfCcutp6hqVzFyh1mxKLe5Kbe2nF65DhiS63ZORp4SQSEbcFSfZob//Q4Dt7g8uiEFvebFfW7sDIjgXlQghEmQTQMTMjkWHAjs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771884888; c=relaxed/simple; bh=4kH174067DzI+LXZAng55RHiqKZbdN+aHW/t4m7nco4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ebrFjN/eS54NYuuBmAJCiupBCgel12pPGFYefXesWMHy5UMiQCG+3vEIytQq2LTj+cK8YSIHOojefLJYoYCbUsvQhdffdvqAXqRnPpyQ6tAWNwcVOBWI86zaMp0YmZ+EXbITIBENwZZq2ccDJjr8CVHXL47b4581Xy66qMQPibI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZC11twMr; 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="ZC11twMr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 251D5C116C6; Mon, 23 Feb 2026 22:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771884888; bh=4kH174067DzI+LXZAng55RHiqKZbdN+aHW/t4m7nco4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZC11twMrmgGTJXn8dEA/A2mDLi28NFLZbvffIeU4a+aHmvvJrlJ/6MAFilWfXwMoJ BSemHdih76UPmdkWqnldt6n3Fwi1hwuMhL2sjp+t0+quDj3jEO3tDCW4YLwT284Foi S6z4FL83KYE7iMUf/E4VETzJoTwEYnnWMCCn1oHhDcBY0jTeijJhWSkeZP27+EhzN7 K9y8QzzUKZ7y2Yy7JG+cNXOJvyfKLAJBpbENYdmP7tGcobH1oj8SZTilY1nTraqXzV 97jfPATwFt7BAhQVY6nKPTJgbx2CemPoFMEn1Wb4HUbmbH589x14g+2VPz4jpZeSXR hU+AR/nmueeDw== Date: Mon, 23 Feb 2026 15:14:45 -0700 From: Tycho Andersen To: Sean Christopherson Cc: Ashish Kalra , Tom Lendacky , John Allen , Herbert Xu , Paolo Bonzini , Shuah Khan , "David S. Miller" , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 3/4] crypto/ccp: support setting RAPL_DIS in SNP_INIT_EX Message-ID: References: <20260223162900.772669-1-tycho@kernel.org> <20260223162900.772669-4-tycho@kernel.org> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Feb 23, 2026 at 08:40:19AM -0800, Sean Christopherson wrote: > On Mon, Feb 23, 2026, Tycho Andersen wrote: > > From: "Tycho Andersen (AMD)" > > > > The kernel allows setting the RAPL_DIS policy bit, but had no way to set > > Please actually say what RAPL_DIS is and does, and explain why this is the > correct approach. I genuinely have no idea what the impact of this patch is, > (beyond disabling something, obviously). Sure, the easiest thing is probably to quote the firmware PDF: Some processors support the Running Average Power Limit (RAPL) feature which provides information about power utilization of software. RAPL can be disabled using the RAPL_DIS flag in SNP_INIT_EX to disable RAPL while SNP firmware is in the INIT state. Guests may require that RAPL is disabled by using the POLICY.RAPL_DIS guest policy flag. I'll add this to the message in the next version. I will also split out the RAPL_DIS stuff from the test fix for the firmware update. Tycho