From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D99EF34BA21; Wed, 17 Sep 2025 16:23:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758126192; cv=none; b=NpYwiB8dct36TYMDxfxwZtOLBNi3PNERRJKkTcRlumWc4kcTZHAuBDxSX6MtLAGDV8pVVFKhyIXhZqvDwI0y9IRqzw3+eKeu/+bA3bYMW1QnO0etkkopJk1zwv6tUBcMXg+S0i3k5aI+f8GCfUYR4fuvfBETGqAcUvZaveJ6Nlc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758126192; c=relaxed/simple; bh=9WSFumWUM+iDYPWeZ4g7rzOwgg3/uhk4ULpV1IZjzl0=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=Pq7bWJ5urgYPa9xswjhKBud9X5GWKWia3I0z1p/k/W2B9lOEUI3IKi31cuAslkAALlezchjtSKFPcdtRn+XaUH+3sSZlrVBUXCtXMwLqZwsXCGJl+8nB7kF9Y7HClLsnRX9dhnyZDvlQ7CojsPrjiMbYeHWnryv7F8akovLNOTI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Kfzj1gnh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Kfzj1gnh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65058C4CEE7; Wed, 17 Sep 2025 16:23:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758126191; bh=9WSFumWUM+iDYPWeZ4g7rzOwgg3/uhk4ULpV1IZjzl0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Kfzj1gnhpIZIlSPLY/n2BOgor5Q8F4ztJr6k1ThhlxR+9gsvxo33Its/rk0lxWDEa kQMdfrnrLDl4nFOaB8Rp1etdML05U2P1DIxf8tbpfbCHL7R5d7R9ZFVsR8H0uV7JhE BH+95ZqPe7PISfmGarbuBioxBTAXfUP7jg5saw4yLgYpNB6RwTgNaOYux39yx7hB3e FET/o+5vB5i3A9XWDEqsUualCOk6gxTzumiLMP1GbDQ9+6LOekeCvcQCOIXWug3AlP D6nvLVHTS0IJadn4FFX/GbvGR63mT/jj+VNRCG6b0DA1DZHMZh8lFc3v/K9PX4QOYa ALNAw4EYVBjPA== 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 4.98.2) (envelope-from ) id 1uyuw1-000000079gN-05oW; Wed, 17 Sep 2025 16:23:09 +0000 Date: Wed, 17 Sep 2025 17:23:08 +0100 Message-ID: <86o6r9121f.wl-maz@kernel.org> From: Marc Zyngier To: Sascha Bischoff Cc: "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , nd , "oliver.upton@linux.dev" , Joey Gouly , Suzuki Poulose , "yuzenghui@huawei.com" , "will@kernel.org" , "tglx@linutronix.de" , "lpieralisi@kernel.org" , Timothy Hayes Subject: Re: [PATCH 1/5] KVM: arm64: Allow ICC_SRE_EL2 accesses on a GICv5 host In-Reply-To: <20250828105925.3865158-2-sascha.bischoff@arm.com> References: <20250828105925.3865158-1-sascha.bischoff@arm.com> <20250828105925.3865158-2-sascha.bischoff@arm.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) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: Sascha.Bischoff@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, nd@arm.com, oliver.upton@linux.dev, Joey.Gouly@arm.com, Suzuki.Poulose@arm.com, yuzenghui@huawei.com, will@kernel.org, tglx@linutronix.de, lpieralisi@kernel.org, Timothy.Hayes@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Thu, 28 Aug 2025 11:59:42 +0100, Sascha Bischoff wrote: > > The bet0 release of the GICv5 specification didn't include the > ICC_SRE_EL2 register as part of FEAT_GCIE_LEGACY. This was an > oversight, and support for this register has been added as of the bet1 > release of the specification. > > Remove the guarding in the vGICv3 code that skipped the ICC_SRE_EL2 > accesses for a GICv5 host. As a result of this change, it now becomes > possible to use nested virtualisation on a GICv5 host when running > legacy GICv3-based VMs. > > Signed-off-by: Sascha Bischoff I just remembered my promise from almost 3 weeks ago, and just posted this: https://lore.kernel.org/r/20250917161935.1630908-1-maz@kernel.org which kills two birds with one stone. I'll take it as a prefix to this series. Thanks, M. -- Without deviation from the norm, progress is not possible.