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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3E62EE4996 for ; Mon, 21 Aug 2023 17:30:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232139AbjHURar (ORCPT ); Mon, 21 Aug 2023 13:30:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234970AbjHURaq (ORCPT ); Mon, 21 Aug 2023 13:30:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0006D124 for ; Mon, 21 Aug 2023 10:30:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4AEAE63B41 for ; Mon, 21 Aug 2023 17:30:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8339C433C9; Mon, 21 Aug 2023 17:30:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692639031; bh=SfyXt+e5RJK+sTZlB9Ncbo3gaHqnWHAg7lpQwU3xZlg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=N0SznYOQd7GlX5kumiH/I/OiJgAz6XAxocEt5lu9BwvxI7vN/ZgqV9lWiD9PiwVEm Vr173EiYI7LSSFGO9U45TrJBjgAyACeHdhvrz3XJRrfi6TF2B0cqjU/oFkjMfpSG7D nb4cg7KMWbWM67wLuTV2l1AFz+8vAQ+uBgni71Ij4uC0XIehcWJ0+kc8VkZ8NiGJoD 5aVM52TSvLPO+FXv3hi90a7GHP1Rd4z4Jf8bfdwf05gUUTj3FYP4Cftb/zwjNlxBXk r74r5oFiGCxjvsziZfQXi0sDTnreUz3cdqoPb5S9QUFqc0UiAJvND87Hj7PAZ5rpHG 1FL9OH74b+Khg== Received: from disco-boy.misterjones.org ([217.182.43.188] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qY8jV-006mxX-6r; Mon, 21 Aug 2023 18:30:29 +0100 MIME-Version: 1.0 Date: Mon, 21 Aug 2023 18:30:28 +0100 From: Marc Zyngier To: Jing Zhang Cc: Cornelia Huck , KVM , KVMARM , ARMLinux , Oliver Upton , Will Deacon , Paolo Bonzini , James Morse , Alexandru Elisei , Suzuki K Poulose , Fuad Tabba , Reiji Watanabe , Raghavendra Rao Ananta , Suraj Jitindar Singh Subject: Re: [PATCH v8 02/11] KVM: arm64: Document KVM_ARM_GET_REG_WRITABLE_MASKS In-Reply-To: References: <20230807162210.2528230-1-jingzhangos@google.com> <20230807162210.2528230-3-jingzhangos@google.com> <878raex8g0.fsf@redhat.com> <874jkyqe13.fsf@redhat.com> <86sf8hg45k.wl-maz@kernel.org> User-Agent: Roundcube Webmail/1.4.13 Message-ID: X-Sender: maz@kernel.org Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 217.182.43.188 X-SA-Exim-Rcpt-To: jingzhangos@google.com, cohuck@redhat.com, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, oliver.upton@linux.dev, will@kernel.org, pbonzini@redhat.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, tabba@google.com, reijiw@google.com, rananta@google.com, surajjs@amazon.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2023-08-21 18:24, Jing Zhang wrote: > On Thu, Aug 17, 2023 at 7:00 AM Marc Zyngier wrote: >> >> On Thu, 17 Aug 2023 09:16:56 +0100, >> Cornelia Huck wrote: >> > >> > On Mon, Aug 14 2023, Jing Zhang wrote: >> > >> > > Maybe it'd be better to leave this to whenever we do need to add other >> > > range support? >> > >> > My point is: How does userspace figure out if the kernel that is running >> > supports ranges other than id regs? If this is just an insurance against >> > changes that might arrive or not, we can live with the awkward "just try >> > it out" approach; if we think it's likely that we'll need to extend it, >> > we need to add the mechanism for userspace to find out about it now, or >> > it would need to probe for presence of the mechanism... >> >> Agreed. Nothing like the present to address this sort of things. it >> really doesn't cost much, and I'd rather have it right now. >> >> Here's a vague attempt at an advertising mechanism. If people are OK >> with it, I can stash that on top of Jing's series. [...] > Looks good to me. Well, that's of course conditional on the other comments I made against this series. And we're seriously running out of time... M. -- Jazz is not dead. It just smells funny...