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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7E03C07E9D for ; Sat, 24 Sep 2022 18:58:37 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 552594B731; Sat, 24 Sep 2022 14:58:37 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9cOCmfELjXoM; Sat, 24 Sep 2022 14:58:36 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 3BA554B657; Sat, 24 Sep 2022 14:58:36 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2CE514B241 for ; Sat, 24 Sep 2022 14:58:35 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id COjST4RBq6fS for ; Sat, 24 Sep 2022 14:58:34 -0400 (EDT) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id EF59A408AB for ; Sat, 24 Sep 2022 14:58:33 -0400 (EDT) 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 57EDAB80687; Sat, 24 Sep 2022 18:58:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DFCFC433D7; Sat, 24 Sep 2022 18:58:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664045911; bh=VKHT4RTjYkoQW0pFVa05iY4hd4prYOcYP8L9npfI1EM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SFCKCdZKKVAGnL5ECihRh0nlRLjxh3hpLRgHeB+uSabSy+uaOCqvDZcnYd88xBHGH HWWW2QfZlKqBuG1EtYOhVrRh9m019b3vb7EdiBf94bFhxV1qFlYfUHvHg5nVYYeUKk IxgptMtMsQkms/CHbXju+SjujMP98VtoSJ0175lamsop9yxwxPb1csuxIWdg8P3mb7 NWGjgX0RqwW2UE2z5vO8p7DB6Qv26y2IhPr1OAqElDy8Kn4cbURN2F0/bjA5DlGpgK lzS4naApCx0khoSsJTJdrjpFXh+iXeBScbMB//Tcth0r2MPpAvVUdbTErU23h8ruLH geRbanod4dOKQ== Received: from 82-132-234-24.dab.02.net ([82.132.234.24] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1ocAM8-00CNoK-HN; Sat, 24 Sep 2022 19:58:28 +0100 Date: Sat, 24 Sep 2022 19:57:49 +0100 Message-ID: <878rm8ior6.wl-maz@kernel.org> From: Marc Zyngier To: Peter Xu Subject: Re: [PATCH 2/6] KVM: Add KVM_CAP_DIRTY_LOG_RING_ORDERED capability and config option In-Reply-To: References: <20220922170133.2617189-1-maz@kernel.org> <20220922170133.2617189-3-maz@kernel.org> <87czbmjhbh.wl-maz@kernel.org> <87edw1i290.wl-maz@kernel.org> <87czblhv2a.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 82.132.234.24 X-SA-Exim-Rcpt-To: peterx@redhat.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, catalin.marinas@arm.com, bgardon@google.com, shuah@kernel.org, andrew.jones@linux.dev, will@kernel.org, dmatlack@google.com, pbonzini@redhat.com, zhenyzha@redhat.com, shan.gavin@gmail.com, gshan@redhat.com, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, oliver.upton@linux.dev X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kvm@vger.kernel.org, catalin.marinas@arm.com, andrew.jones@linux.dev, will@kernel.org, shan.gavin@gmail.com, bgardon@google.com, dmatlack@google.com, pbonzini@redhat.com, zhenyzha@redhat.com, shuah@kernel.org, kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Sat, 24 Sep 2022 14:22:32 +0100, Peter Xu wrote: > > On Sat, Sep 24, 2022 at 12:26:53PM +0100, Marc Zyngier wrote: > > On Sat, 24 Sep 2022 09:51:39 +0100, > > Marc Zyngier wrote: > > > > > > I'm happy to bikeshed, but please spell it out for me. If we follow > > > the current scheme, we need 3 configuration symbols (of which we > > > already have one), and 2 capabilities (of which we already have one). > > I hope it's not bikeshedding. I normally don't comment on namings at all > because many of them can be "bikeshedding" to me. But this one is so > special because it directly collides with KVM_GET_DIRTY_LOG, which is other > method of dirty tracking. Fair enough. I'm notoriously bad at sticking a name to things, so I'm always happy to receive suggestions. > > > > > > > Do you have any concrete proposal for those? > > > > In order to make some forward progress, I've reworked the series[1] > > with another proposal for those: > > > > Config symbols: > > > > - HAVE_KVM_DIRTY_RING: > > * mostly the same meaning as today > > * not directly selected by any architecture > > * doesn't expose any capability on its own > > > > - HAVE_KVM_DIRTY_RING_TSO: > > * only for strongly ordered architectures > > * selects HAVE_KVM_DIRTY_RING > > * exposes KVM_CAP_DIRTY_LOG_RING > > * selected by x86 > > > > - HAVE_KVM_DIRTY_RING_ACQ_REL: > > * selects HAVE_KVM_DIRTY_RING > > * exposes KVM_CAP_DIRTY_LOG_RING_ACQ_REL > > * selected by arm64 and x86 > > > > Capabilities: > > > > - KVM_CAP_DIRTY_LOG_RING: the good old x86-specific stuff, advertised > > when HAVE_KVM_DIRTY_RING_TSO is selected > > > > - KVM_CAP_DIRTY_LOG_RING_ACQ_REL: the new acquire/release semantics, > > advertised when HAVE_KVM_DIRTY_RING_ACQ_REL is selected > > > > This significantly reduces the churn and makes things slightly more > > explicit. > > This looks good to me, thanks. OK, thanks for having a quick look. I'll repost this shortly, after I'm done reviewing Gavin's series. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm