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 10499C38142 for ; Tue, 31 Jan 2023 20:05:37 +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=6lp989+c0YjLuC18fLbBsI7Mzo/6ryj2BhrngTwxjgE=; b=WO6hWghGkJ/M78 T82Yaa8Z+XLZIyhgM5m3r81KA1dMDPMOsFqYlGKfxOIniY2/lBWAElwrHlVzzwaZaUUpF6YOvOvMn gbQ9tJpqIiODqTuXyWwMXJugs1bygC231wDS1vuJwUEy/B9jOqs2T4Akv/U+vM5PILlD1QWxTRC14 Ahm4xpp7SnOwQ78gsHKcIhno5cdxQuXhVQUuFTzRtNcuMzJ/gpeh0FWd7dZJ1jifWN76NxWBrlwFA TPf82OFJ+pWMC4jEvVXWQ0XxhXf+gVvT/++SUdcdzcWJAHHKX9S5N692DEOhpuDJYkWaQGzYIypOt eBEPPRQk+dA5tgYudTsw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMwrs-009CzZ-W4; Tue, 31 Jan 2023 20:04:37 +0000 Received: from out-125.mta1.migadu.com ([2001:41d0:203:375::7d]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMwrp-009Cw5-JJ for linux-arm-kernel@lists.infradead.org; Tue, 31 Jan 2023 20:04:35 +0000 Date: Tue, 31 Jan 2023 20:04:15 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1675195460; 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=Jh/baY97/lYcQNbE6c9CebV1b/2EgbL4sdH3k9fvFHE=; b=M/c4RHMDqFEIf43nHcq4XXwLj+ZTxS1U72lxJF0AmBav2M9r6VikvQHPN28xq2goZ4XtGl 9XqDq+xHikb+uQqmfHVH8q2XpnErIDdlJlvHv04uKrz9jx76+pf5t81cTV/ljfhiehTPsx lEUaqQxggkPB2PEI8qTBNSQh6l4sN9I= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Suzuki K Poulose Cc: Marc Zyngier , kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Alexandru Elisei , Andre Przywara , Chase Conklin , Christoffer Dall , Ganapatrao Kulkarni , Jintack Lim , Russell King , James Morse , Zenghui Yu Subject: Re: [PATCH v8 01/69] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Message-ID: References: <20230131092504.2880505-1-maz@kernel.org> <20230131092504.2880505-2-maz@kernel.org> <86cz6u248j.wl-maz@kernel.org> <3c15760c-c76f-3d5d-a661-442459ce4e07@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3c15760c-c76f-3d5d-a661-442459ce4e07@arm.com> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230131_120433_838928_92CC95E9 X-CRM114-Status: GOOD ( 14.43 ) 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 Tue, Jan 31, 2023 at 05:34:39PM +0000, Suzuki K Poulose wrote: > On 31/01/2023 14:00, Marc Zyngier wrote: [...] > > What is exactly the objection here? NV is more or less a VHE++ mode, > > but is also completely experimental and incomplete. > > I am all in for making this an "optional", only enabled it when "I know > what I want". > > kvm-arm.mode=nv kind of seems that the KVM driver is conditioned > mainly for running NV (comparing with the other existing options > for kvm-arm.mode). > > In reality, as you confirmed, NV is an *additional* capability > of a VHE hypervisor. So it would be good to "opt" in for "nv" capability > support. > > e.g, > > kvm-arm.nv=on > > Thinking more about it, either is fine. Marc, I'm curious, how do you plan to glue hVHE + NV together (if at all)? We may need two separate options for this so the user could separately configure NV for their hVHE KVM instance. -- Thanks, Oliver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel