From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta1.migadu.com (out-188.mta1.migadu.com [95.215.58.188]) (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 418C4210E6 for ; Mon, 5 Feb 2024 13:21:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707139293; cv=none; b=gqKY0JOViU5/gNjpiZ6fTdXZ7dT3Mfb2opv62HkwBKfGN5B1W3qSmrEh3yp2G85e+2gmU+neWyTfY08hpMQNJKq4hsjxmDu8LLMa52d/hEbCGyH7N7Y7t1uaoicJe5licjuuNHove8NM6SqoRzPUoXL4qeVeX6+kPgDwNyF9nDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707139293; c=relaxed/simple; bh=mDdBJfptNTRev8vYPas+YaJMyNsKhfsljBz9EaTVLlI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d4V285T15cAu9ZWb4gZ0/B2RwuQv0QVVE+aiIHCmSyc1wh78cjKk/RsZcfWKi8xT/tuNQJCOxmWvTprWErVzYF443y3m1+gzezFg4NTuyw8xsz1D0ifFyaDtfeHai9UQvCw71vLUisBmxJDgntkp45MqfMtt8Dg56soGAYxTbw8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=YbgN3AeY; arc=none smtp.client-ip=95.215.58.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="YbgN3AeY" Date: Mon, 5 Feb 2024 13:21:26 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1707139289; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=r8wLnWWA4PkBzsgde5n7CqFtTqXJKCoOlinRqF4VWvs=; b=YbgN3AeYOgNDxaxv3aL5Fi28ARY/eOEICeZpSZRF0YfQU1YAdGSQfeldDujThmMNVzkW2y 30AMFFza0kmkbbJaalH9ea8uNYwRzjjABMlX74rwrM1rqkPl9nnwfsR+UVZlgwsd2NQw6B kIbtuNJxoUI8q6fyV5ZW3UenW76RkIM= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: James Clark , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, broonie@kernel.org, suzuki.poulose@arm.com, acme@kernel.org, James Morse , Zenghui Yu , Catalin Marinas , Will Deacon , Mike Leach , Leo Yan , Alexander Shishkin , Anshuman Khandual , Rob Herring , Miguel Luis , Jintack Lim , Ard Biesheuvel , Mark Rutland , Arnd Bergmann , Vincent Donnefort , Kristina Martsenko , Fuad Tabba , Joey Gouly , Akihiko Odaki , Jing Zhang , linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 2/7] arm64: KVM: Use shared area to pass PMU event state to hypervisor Message-ID: References: <20240104162714.1062610-1-james.clark@arm.com> <20240104162714.1062610-3-james.clark@arm.com> <8a908ee8-620a-d9c2-734b-5a6402950072@arm.com> <867cjj6ohz.wl-maz@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=us-ascii Content-Disposition: inline In-Reply-To: <867cjj6ohz.wl-maz@kernel.org> X-Migadu-Flow: FLOW_OUT On Mon, Feb 05, 2024 at 01:15:36PM +0000, Marc Zyngier wrote: > On Mon, 05 Feb 2024 13:04:51 +0000, > Oliver Upton wrote: > > > > Unless someone has strong opinions about making this work in protected > > mode, I am happy to see tracing support limited to the 'normal' nVHE > > configuration. The protected feature as a whole is just baggage until > > upstream support is completed. > > Limiting tracing to non-protected mode is a must IMO. Allowing tracing > when pKVM is enabled is a sure way to expose secrets that should > stay... secret. The only exception I can think of is when > CONFIG_NVHE_EL2_DEBUG is enabled, at which point all bets are off. Zero argument there :) I left off the "and PMU" part of what I was saying, because that was a feature that semi-worked in protected mode before VM/VCPU shadowing support landed. -- Thanks, Oliver