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[34.90.227.64]) by smtp.gmail.com with ESMTPSA id x1-20020a05640226c100b00443d657d8a4sm2435255edd.61.2022.10.28.02.57.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 02:57:07 -0700 (PDT) Date: Fri, 28 Oct 2022 09:57:04 +0000 From: Quentin Perret To: Oliver Upton Subject: Re: [PATCH 2/2] KVM: arm64: Redefine pKVM memory transitions in terms of source/target Message-ID: References: <20221028083448.1998389-1-oliver.upton@linux.dev> <20221028083448.1998389-3-oliver.upton@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221028083448.1998389-3-oliver.upton@linux.dev> Cc: kvm@vger.kernel.org, Marc Zyngier , Will Deacon , kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org 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 Hey Oliver, On Friday 28 Oct 2022 at 08:34:48 (+0000), Oliver Upton wrote: > Perhaps it is just me, but the 'initiator' and 'completer' terms are > slightly confusing descriptors for the addresses involved in a memory > transition. Apply a rename to instead describe memory transitions in > terms of a source and target address. Just to provide some rationale for the initiator/completer terminology, the very first implementation we did of this used 'sender/recipient (or something along those lines I think), and we ended up confusing ourselves massively. The main issue is that memory doesn't necessarily 'flow' in the same direction as the transition. It's all fine for a donation or a share, but reclaim and unshare become funny. 'The recipient of an unshare' can be easily misunderstood, I think. So yeah, we ended up with initiator/completer, which may not be the prettiest terminology, but it was useful to disambiguate things at least. Thanks for the review! Quentin _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f44.google.com (mail-ed1-f44.google.com [209.85.208.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 230BC1FAE for ; Fri, 28 Oct 2022 09:57:09 +0000 (UTC) Received: by mail-ed1-f44.google.com with SMTP id i21so7097260edj.10 for ; Fri, 28 Oct 2022 02:57:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=mvHL5Drr+3t1aS/5ADf3q7iM5WIuHk2AYt4Ze0ZBgjk=; b=XzOlmJP/jS7VT1xg6wG+42FDDXw981TfzCCruFtGWZepNQEEDI1xBoIQxendEL6nVw gV++vJ7t7L7EWZHnXPGmx0WFIw3SkrgmFHy7yiCJmdCaMetbBp4gmGb8H0OpwnEhz4uA NXR0EIjkLtokHm+btvWViZasIH8uRkLuXGJU84pBFCN9ZAMKWmzhw1vgpkv0EaZCYXGC lRB/IpHGfMApklvbsCU3KW8TkXSHNoNTekYSvt6CgCgcciE56e87YjFKyn9JXOirreG8 e5BSpaR4vnFx+66Pxz1mIral+3sROyLK+wRy96aO3CnMOlMYCH/XbevP2WLneL9Q/7Yd BWDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=mvHL5Drr+3t1aS/5ADf3q7iM5WIuHk2AYt4Ze0ZBgjk=; b=kxCTOrH7dUAgd2OE3WaUepCwBEMbaAeZeRicy8C15ZCt8bza0kxq1XvaKIYdp9+CfT XDoYMyzNMv3/97YBGqvhqOoS4qvsLO6jaT7jfgWsPlzb9HI96B7ClBi3Lrg5hrHrsgTs QXypiasOnxZMR0MNWBKzDpzgv0nNfOxWxpOIfApmh08xfvGO/9okgoAlbKRdZuVPE383 cWAp2qkGpUrR7xJOH7YXrIxqmwF5vvQ2kqefO7kJn3ik8l1I3vAsYSdAhonysRLaGb8+ 1JGklgbCYOpabCLq8CKJW4tjx32mKJhV4hWcsYkptYq04lQOB2H4FbJsTp7d1WO2Yg4T q/KQ== X-Gm-Message-State: ACrzQf1tyy11MvknV+5tw+XI29uQpV9cSYTm6eVi46N22kLL2UjmWRgY til9b9Ad9XG3RZY5e0NYlcPA/A== X-Google-Smtp-Source: AMsMyM5zJVsp3vp9yM+1qZ9xU/7wt91EQOkPXZmY19wmU4+a4o6tvJjAEaJRmC8JNHIxmOjkkdPfsw== X-Received: by 2002:a50:ff09:0:b0:456:fd61:83b3 with SMTP id a9-20020a50ff09000000b00456fd6183b3mr48978165edu.166.1666951028189; Fri, 28 Oct 2022 02:57:08 -0700 (PDT) Received: from google.com (64.227.90.34.bc.googleusercontent.com. [34.90.227.64]) by smtp.gmail.com with ESMTPSA id x1-20020a05640226c100b00443d657d8a4sm2435255edd.61.2022.10.28.02.57.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 02:57:07 -0700 (PDT) Date: Fri, 28 Oct 2022 09:57:04 +0000 From: Quentin Perret To: Oliver Upton Cc: Marc Zyngier , James Morse , Alexandru Elisei , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, kvmarm@lists.linux.dev, Will Deacon , Fuad Tabba , Vincent Donnefort Subject: Re: [PATCH 2/2] KVM: arm64: Redefine pKVM memory transitions in terms of source/target Message-ID: References: <20221028083448.1998389-1-oliver.upton@linux.dev> <20221028083448.1998389-3-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221028083448.1998389-3-oliver.upton@linux.dev> Message-ID: <20221028095704.kmFYUgdLEDJzgEqyIvrXEr5ICsCuSpRnRlsKsIjCRDE@z> Hey Oliver, On Friday 28 Oct 2022 at 08:34:48 (+0000), Oliver Upton wrote: > Perhaps it is just me, but the 'initiator' and 'completer' terms are > slightly confusing descriptors for the addresses involved in a memory > transition. Apply a rename to instead describe memory transitions in > terms of a source and target address. Just to provide some rationale for the initiator/completer terminology, the very first implementation we did of this used 'sender/recipient (or something along those lines I think), and we ended up confusing ourselves massively. The main issue is that memory doesn't necessarily 'flow' in the same direction as the transition. It's all fine for a donation or a share, but reclaim and unshare become funny. 'The recipient of an unshare' can be easily misunderstood, I think. So yeah, we ended up with initiator/completer, which may not be the prettiest terminology, but it was useful to disambiguate things at least. Thanks for the review! Quentin 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C8C3AC38A02 for ; Fri, 28 Oct 2022 10:05:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=DQlnxvp6WZXfq4DOfTzpYXWvAuJqE8Ddp6qK6aDrZ6M=; b=1Z6BdAXRdELxcR 0Mgrc34qoQHg1v54RJLsT/dmcSKUFjYBV6teV9DGOJ5TtphMRZOCkdvK3VbcoFByb/yXvByv44nHP L+myyq2R1xNCZNtqEWyOIAl5Uab14jgMhjcWAp5RNuetG6Sxiu+5wKiMofsBWo70TuytF5w1eigef pBXO7uk3rPVegj8KEWSyEgioS6RMr2qoXsCwvPlPBt/57M11+zziwt0QBRo+O9/y14TlKhBs8Us9V tRka+b6XIQWsnHigp/Uz7YDLUa3VroR6NVUKSAYWnEU+HcmgyxNW6qb5yukHFZ320f560TT47yY/k 1mx5qqbEhdxznk37xg3A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ooMDu-00GWEo-N2; Fri, 28 Oct 2022 10:04:24 +0000 Received: from mail-ed1-x52e.google.com ([2a00:1450:4864:20::52e]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ooM6w-00GTUe-Bl for linux-arm-kernel@lists.infradead.org; Fri, 28 Oct 2022 09:57:11 +0000 Received: by mail-ed1-x52e.google.com with SMTP id m15so7069146edb.13 for ; Fri, 28 Oct 2022 02:57:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=mvHL5Drr+3t1aS/5ADf3q7iM5WIuHk2AYt4Ze0ZBgjk=; b=XzOlmJP/jS7VT1xg6wG+42FDDXw981TfzCCruFtGWZepNQEEDI1xBoIQxendEL6nVw gV++vJ7t7L7EWZHnXPGmx0WFIw3SkrgmFHy7yiCJmdCaMetbBp4gmGb8H0OpwnEhz4uA NXR0EIjkLtokHm+btvWViZasIH8uRkLuXGJU84pBFCN9ZAMKWmzhw1vgpkv0EaZCYXGC lRB/IpHGfMApklvbsCU3KW8TkXSHNoNTekYSvt6CgCgcciE56e87YjFKyn9JXOirreG8 e5BSpaR4vnFx+66Pxz1mIral+3sROyLK+wRy96aO3CnMOlMYCH/XbevP2WLneL9Q/7Yd BWDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=mvHL5Drr+3t1aS/5ADf3q7iM5WIuHk2AYt4Ze0ZBgjk=; b=XQc7HULEhwJKdOeL99bit8y625Ne5OH5zmrV3gLrOOOOK0Y2NMs48q7rfQZcMpu+OO QW2e0qpF5eY0t3oJqid2H7K6Be7ZmZpbP7qJVbL40VLC9//KPB4FODBgLwuB+50rBPkd AgdAyi3hGq0PZ7Hi3QpmRav00rQdQFv/UlodPT+5Y5sHzvvb2GhyDs50NAGLKaCYn4H4 sjtswk2TeaEjedQVNqKkaFR1iz2e1iQgPG1Zal6jauEXi5/u45TN5D/LxsQNPRzDMgeq LlZdS9L7VM9Ur7JOF1bzPGOrlrfX5WRGBgnNOa2A3T0js4Bcee5CXaAIMxUnRuhGMDvC 5kGA== X-Gm-Message-State: ACrzQf0FtS2BxxwrxGAb/RLSJ96j3JnNVKkbkwkAgoOri+munLTdnbFU L0Qj2P/+aqxuQJBTp4ai+6/w4g== X-Google-Smtp-Source: AMsMyM5zJVsp3vp9yM+1qZ9xU/7wt91EQOkPXZmY19wmU4+a4o6tvJjAEaJRmC8JNHIxmOjkkdPfsw== X-Received: by 2002:a50:ff09:0:b0:456:fd61:83b3 with SMTP id a9-20020a50ff09000000b00456fd6183b3mr48978165edu.166.1666951028189; Fri, 28 Oct 2022 02:57:08 -0700 (PDT) Received: from google.com (64.227.90.34.bc.googleusercontent.com. [34.90.227.64]) by smtp.gmail.com with ESMTPSA id x1-20020a05640226c100b00443d657d8a4sm2435255edd.61.2022.10.28.02.57.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 02:57:07 -0700 (PDT) Date: Fri, 28 Oct 2022 09:57:04 +0000 From: Quentin Perret To: Oliver Upton Cc: Marc Zyngier , James Morse , Alexandru Elisei , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, kvmarm@lists.linux.dev, Will Deacon , Fuad Tabba , Vincent Donnefort Subject: Re: [PATCH 2/2] KVM: arm64: Redefine pKVM memory transitions in terms of source/target Message-ID: References: <20221028083448.1998389-1-oliver.upton@linux.dev> <20221028083448.1998389-3-oliver.upton@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221028083448.1998389-3-oliver.upton@linux.dev> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221028_025710_450114_A8ACDA00 X-CRM114-Status: GOOD ( 12.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hey Oliver, On Friday 28 Oct 2022 at 08:34:48 (+0000), Oliver Upton wrote: > Perhaps it is just me, but the 'initiator' and 'completer' terms are > slightly confusing descriptors for the addresses involved in a memory > transition. Apply a rename to instead describe memory transitions in > terms of a source and target address. Just to provide some rationale for the initiator/completer terminology, the very first implementation we did of this used 'sender/recipient (or something along those lines I think), and we ended up confusing ourselves massively. The main issue is that memory doesn't necessarily 'flow' in the same direction as the transition. It's all fine for a donation or a share, but reclaim and unshare become funny. 'The recipient of an unshare' can be easily misunderstood, I think. So yeah, we ended up with initiator/completer, which may not be the prettiest terminology, but it was useful to disambiguate things at least. Thanks for the review! Quentin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel