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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 5E74AC54F30 for ; Tue, 27 May 2025 14:16:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uJv5c-0000Z9-T2; Tue, 27 May 2025 10:15:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uJv5T-0000Wg-MW; Tue, 27 May 2025 10:15:29 -0400 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uJv5N-00087r-GI; Tue, 27 May 2025 10:15:27 -0400 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 52E3B5C1D0A; Tue, 27 May 2025 14:12:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03B02C4CEE9; Tue, 27 May 2025 14:15:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748355312; bh=g1k9FRzqLORXJS5ACE8FbcuyWdMPc4sfhJTsJPJL9pQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Q3j0sxotIDFaWBH7OOm8LzulaiGjoGSiB5eTzamONotcD8SuZo/dgw5Lc2HmuPfwV AHTZKZQiISaNniK6HucF+Tg4gG3DCEYOzvH2Z4ZmRm+Ty5DmSgPrGwN510PwEvqTeV QFQpJGJ40eyUw53pgFDFiAmR5qrgN9LJiIF8BmPaxfM1gg8vQSbHBHX4anS9ASfQK8 uPGj7+lNO/NB9XklOGzyp/dDnukaO4KgZSZuTTpC+ESM28EBZhEr90tDTt5njdddsu Z/Vnq5c5mpw+z4c/81xr2dEZLxca5o7TtH3ESPUi9yPIzcfq78pa/82MCTEVhkjwki /R4PylvWeuhmA== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.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 1uJv5B-000tyG-9j; Tue, 27 May 2025 15:15:09 +0100 Date: Tue, 27 May 2025 15:15:08 +0100 Message-ID: <86h616dtsj.wl-maz@kernel.org> From: Marc Zyngier To: eric.auger@redhat.com Cc: Miguel Luis , "eric.auger.pro@gmail.com" , "qemu-devel@nongnu.org" , "qemu-arm@nongnu.org" , "peter.maydell@linaro.org" , "richard.henderson@linaro.org" , "gkulkarni@amperecomputing.com" , "gankulkarni@os.amperecomputing.com" Subject: Re: [PATCH v5 0/5] ARM Nested Virt Support In-Reply-To: References: <20250527062534.1186004-1-eric.auger@redhat.com> <86ldqidzyl.wl-maz@kernel.org> <822E77EF-9802-4F16-B8D4-A48F3A624151@oracle.com> 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/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: eric.auger@redhat.com, miguel.luis@oracle.com, eric.auger.pro@gmail.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, richard.henderson@linaro.org, gkulkarni@amperecomputing.com, gankulkarni@os.amperecomputing.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Received-SPF: pass client-ip=2604:1380:4641:c500::1; envelope-from=maz@kernel.org; helo=dfw.source.kernel.org X-Spam_score_int: -49 X-Spam_score: -5.0 X-Spam_bar: ----- X-Spam_report: (-5.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.907, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, 27 May 2025 14:11:41 +0100, Eric Auger wrote: >=20 > Hi Miguel, Marc, >=20 > On 5/27/25 2:54 PM, Miguel Luis wrote: > > > >> On 27 May 2025, at 12:01, Marc Zyngier wrote: > >> > >> On Tue, 27 May 2025 12:33:23 +0100, > >> Miguel Luis wrote: > >>> Hi Eric, > >>> > >>>> On 27 May 2025, at 06:24, Eric Auger wrote: > >>>> > >>>> Now that ARM nested virt has landed in kvm/next, let's turn the seri= es > >>>> into a PATCH series. The linux header update was made against kvm/ne= xt. > >>>> > >>>> For gaining virt functionality in KVM accelerated L1, The host needs= to > >>>> be booted with "kvm-arm.mode=3Dnested" option and qemu needs to be i= nvoked > >>>> with: -machine virt,virtualization=3Don. > >>> For the current kvmarm/next the guest also needs > >>> =E2=80=9Ckvm-arm.mode=3Dnested=E2=80=9D I believe. > >> No, unless you want the guest itself to be NV-capable. > Effectively you don't need "kvm-arm.mode=3Dnested" except if you want want > multiple level of nesting. You need kvm-arm.mode=3Dnested on the command-line of a kernel that acts as a host exposing KVM_CAP_ARM_EL2. This is obviously a recursive property, but that's for the user to decide if they want it or not. > > Correct, I got carried away with some mode combinations. Maybe we shoul= d depict > > here more broadly how NV might be used with different mode combinations= . I'll > > think about this further ahead. > > > > As far this series go I couldn't found any issue booting a L1 guest with > > virtualization=3Don and a L2 guest with virtualization=3Doff. >=20 > on my end I tested with various untouched L2 guests (debian, fed, rhel) > in 4kB/4kB/4KB page size mode (host, L1, L2). Those configs were successf= ul. I'm doing 4/4/4 (x1e) and 16/16/4 (m2). I'm also doing 4/4/4/4/4, but that's not very reliable yet, > with 64kB/64kB/64kB configs I am less lucky atm. One one machine I > cannot boot L1 with virtualization=3Don. On the other I can boot L1 but > cannot boot L2. I think x1e supports 64k pages, but I'd need to try. Not exactly the highest priority on my list of things to debug. > Trying my best to debug a little bit further with my setup. Anyway if > somebody else can try 64kB configs, it would help to confirm whether > there are pending issues. I don't think they are related to this qemu > integration series though. Yeah, definitely a kernel issue IMO. Thanks, M. --=20 Without deviation from the norm, progress is not possible.