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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA832C07E9B for ; Wed, 21 Jul 2021 08:24:39 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 8CEE760FDA for ; Wed, 21 Jul 2021 08:24:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8CEE760FDA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9FQ+Z/Lrgpt7dch3WW62bv3nu6kx+OetECUgMe5f1jE=; b=G28lYxBVLa4AZh 9cPwhXZn//CHHn3NsKBNRz/YOsIzITuaUsgvLtd3C2pOtTHcyddZMvmPnqiuoLayUtKgS09kuwMbY TzkSdbo6kaIzGGptXHinbJDlBHthzHUJzw8/btRmzYu6qF7t8iuhOZFK58JwPXm/a7SFBhJD4ec/s 6vfSvdsWHgJepPb91xFozbLBuuuGCoaxskYC2/imV2wek2mRqpiwXK/IlWMIvP5Ec1PuT2zAwdwsM mGWTvwUe2Zf7ItkXptrdVPGcQKDEQcCEE3lE7a2Dpc6pqEJRXH0e8yMqLJGEGOhYoE4/pgHBMGDxQ nzLULNrM89VcIY6e6slg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m67VY-00Et3w-Sg; Wed, 21 Jul 2021 08:23:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m67VO-00Et1Y-HA for linux-arm-kernel@lists.infradead.org; Wed, 21 Jul 2021 08:23:03 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 46F786120A; Wed, 21 Jul 2021 08:23:02 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1m67VM-00Eev3-8O; Wed, 21 Jul 2021 09:23:00 +0100 Date: Wed, 21 Jul 2021 09:22:44 +0100 Message-ID: <87im142i0b.wl-maz@kernel.org> From: Marc Zyngier To: Sergey Senozhatsky Cc: Will Deacon , Suleiman Souhlal , Joel Fernandes , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCHv2 2/4] arm64: add guest pvstate support In-Reply-To: References: <20210709043713.887098-1-senozhatsky@chromium.org> <20210709043713.887098-3-senozhatsky@chromium.org> <877dhv35ea.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: 185.219.108.64 X-SA-Exim-Rcpt-To: senozhatsky@chromium.org, will@kernel.org, suleiman@google.com, joelaf@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210721_012302_643376_1F4D4C7E X-CRM114-Status: GOOD ( 19.08 ) 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 On Wed, 21 Jul 2021 03:05:25 +0100, Sergey Senozhatsky wrote: > > On (21/07/12 16:42), Marc Zyngier wrote: > > > > > > PV-vcpu-state is a per-CPU struct, which, for the time being, > > > holds boolean `preempted' vCPU state. During the startup, > > > given that host supports PV-state, each guest vCPU sends > > > a pointer to its per-CPU variable to the host as a payload > > > > What is the expected memory type for this memory region? What is its > > life cycle? Where is it allocated from? > > Guest per-CPU area, which physical addresses is shared with the > host. Again: what are the memory types you expect this to be used with? When will the hypervisor ever stop accessing this? How does it work across reset? I'm sorry to be that pressing, but these are the gory details that actually matter if you want this thing to be maintainable. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel