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 A4382C9EC9C for ; Mon, 12 Jan 2026 16:20:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To: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=1d5Rc0+Kuv9IDFedTg1SjWNsjMqHZeOuT+hIBU9nhHY=; b=HHriG9XlGZ2twYj0J6zCF2RUTd b8v3goNz0d6lRBtQx24TfOhifaGMe5bZbrNhm7687PNVuKkOzsYT9uvudKUPv1buz3Bi+I1WDxCUT XeDPJEAdIA9XFSu215gktyAMIC6s7Jy0KXj1MKiQLSwpKRMpVytSph4/1vT/VSMWig7VSimCTaTDg MrbYs5RbK9sQea0FFHFgQypnIWvknskC/Wvt/zY0vFmGZGQxG4nWDK+OvMNSu8p+8nJo0yzRnzFFe oQbK61ZbLZHfxlSPoBDSd9gwJZ3hdf4Wrcw9SJTeb2c04+XhGgcD44Vi0CQ/xSz+3uvj3ObkCssvD /9IK9wbg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfKez-00000005iUX-0W1l; Mon, 12 Jan 2026 16:20:53 +0000 Received: from sinmsgout03.his.huawei.com ([119.8.177.38]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfKev-00000005iTg-48ro for linux-arm-kernel@lists.infradead.org; Mon, 12 Jan 2026 16:20:51 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=1d5Rc0+Kuv9IDFedTg1SjWNsjMqHZeOuT+hIBU9nhHY=; b=sldR3HrTIWAGi+oNR19/urwfy1QBClv9QNRlcVbqP29cpaiswwSW9ZC4CXihPgaFMeUhwCxc3 jyIn6pnlee+VPYjZrB8HW3dTXRHDv3K5NCBUu7XOPHnPcGosi9HzIEKgI/ZFjUwLMlwjzcqKSh6 b4vPozeIy6sr2mLMDUGLwNk= Received: from frasgout.his.huawei.com (unknown [172.18.146.32]) by sinmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4dqcxW1FyGzMqh8; Tue, 13 Jan 2026 00:18:23 +0800 (CST) Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dqczl217mzHnGhV; Tue, 13 Jan 2026 00:20:19 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 8C42C40569; Tue, 13 Jan 2026 00:20:35 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Mon, 12 Jan 2026 16:20:34 +0000 Date: Mon, 12 Jan 2026 16:20:33 +0000 From: Jonathan Cameron To: Sascha Bischoff CC: "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.linux.dev" , "kvm@vger.kernel.org" , nd , "maz@kernel.org" , "oliver.upton@linux.dev" , Joey Gouly , Suzuki Poulose , "yuzenghui@huawei.com" , "peter.maydell@linaro.org" , "lpieralisi@kernel.org" , Timothy Hayes Subject: Re: [PATCH v3 24/36] KVM: arm64: gic-v5: Create, init vgic_v5 Message-ID: <20260112162033.000078d5@huawei.com> In-Reply-To: <20260109170400.1585048-25-sascha.bischoff@arm.com> References: <20260109170400.1585048-1-sascha.bischoff@arm.com> <20260109170400.1585048-25-sascha.bischoff@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml500009.china.huawei.com (7.191.174.84) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260112_082050_446247_02697F5C X-CRM114-Status: GOOD ( 26.65 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 9 Jan 2026 17:04:47 +0000 Sascha Bischoff wrote: > Update kvm_vgic_create to create a vgic_v5 device. When creating a > vgic, FEAT_GCIE in the ID_AA64PFR2 is only exposed to vgic_v5-based > guests, and is hidden otherwise. GIC in ~ID_AA64PFR0_EL1 is never > exposed for a vgic_v5 guest. > > When initialising a vgic_v5, skip kvm_vgic_dist_init as GICv5 doesn't > support one. The current vgic_v5 implementation only supports PPIs, so > no SPIs are initialised either. > > The current vgic_v5 support doesn't extend to nested guests. Therefore, > the init of vgic_v5 for a nested guest is failed in vgic_v5_init. > > As the current vgic_v5 doesn't require any resources to be mapped, > vgic_v5_map_resources is simply used to check that the vgic has indeed > been initialised. Again, this will change as more GICv5 support is > merged in. > > Signed-off-by: Sascha Bischoff > Reviewed-by: Jonathan Cameron Minor patch break up comment below. No need to change unless maintainers ask for it I think. Jonathan > --- > arch/arm64/kvm/vgic/vgic-init.c | 60 +++++++++++++++++++++------------ > arch/arm64/kvm/vgic/vgic-v5.c | 26 ++++++++++++++ > arch/arm64/kvm/vgic/vgic.h | 2 ++ > include/kvm/arm_vgic.h | 1 + > 4 files changed, 68 insertions(+), 21 deletions(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c > index 973bbbe56062c..bde5544b58b09 100644 > --- a/arch/arm64/kvm/vgic/vgic-init.c > +++ b/arch/arm64/kvm/vgic/vgic-init.c > @@ -418,22 +425,28 @@ int vgic_init(struct kvm *kvm) > if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus)) > return -EBUSY; > > - /* freeze the number of spis */ > - if (!dist->nr_spis) > - dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS; > + if (!vgic_is_v5(kvm)) { > + /* freeze the number of spis */ > + if (!dist->nr_spis) > + dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS; > > - ret = kvm_vgic_dist_init(kvm, dist->nr_spis); > - if (ret) > - goto out; > + ret = kvm_vgic_dist_init(kvm, dist->nr_spis); > + if (ret) > + return ret; > > - /* > - * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs, > - * vLPIs) is supported. > - */ > - if (vgic_supports_direct_irqs(kvm)) { > - ret = vgic_v4_init(kvm); > + /* > + * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs, > + * vLPIs) is supported. > + */ > + if (vgic_supports_direct_irqs(kvm)) { > + ret = vgic_v4_init(kvm); > + if (ret) > + return ret; > + } > + } else { > + ret = vgic_v5_init(kvm); > if (ret) > - goto out; > + return ret; > } > > kvm_for_each_vcpu(idx, vcpu, kvm) > @@ -441,11 +454,11 @@ int vgic_init(struct kvm *kvm) > > ret = kvm_vgic_setup_default_irq_routing(kvm); > if (ret) > - goto out; > + return ret; > > vgic_debug_init(kvm); > dist->initialized = true; > -out: It is a bit marginal on whether it is worth the effort but I think this would been slightly clearer if a precursor patch had dealt with the early returns. > + > return ret; return 0; Always nice to be explicit when it is a good exit path. > } >