From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 694D1606A324 for ; Mon, 26 Oct 2026 19:12:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=A1qxBmI1; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Gvl/U9ym 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=/xdSDdeNwO4oLUk3isMtVnIVH6TEXIfV4gp7YgJ8B1k=; b=A1qxBmI1gzjNa02SLF9lxqWDM0 70sm5788E9GBYdveVdlObyZtpXKUpqCdYLDaQrSUy9rGZrPsCcz4sxS4iRawZvA4LD20IV0IDSyea ZnsnpUfzjs31jyE+H389sGPaaYhN0BmWpdsqBm97mbwsuXCGKJgNH05JAIOzHpt3k15+wblJyZlw/ 7kzuCO6ApaHkniyJpNuCvGEflYBz7JTZY5wigD3diDrafwYqhf3RWPleKyZRyyiFXA8sEFJ5VNR1V HjJCcgeCrqRrqFC6/hLYbir4B5XEWD7hTIjQzgl5Es/2amcggjjfEiHjiX8Bn2BUGYanAoiWeCPTR NUMTPySA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLQ7P-0000000391u-1oFi; Mon, 26 Oct 2026 19:12:27 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLQ7O-0000000391c-0YqI for linux-arm-kernel@lists.infradead.org; Mon, 26 Oct 2026 19:12:26 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 42E4460A6B; Mon, 26 Oct 2026 19:12:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7A191F01825; Mon, 26 Oct 2026 19:12:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793041945; bh=/xdSDdeNwO4oLUk3isMtVnIVH6TEXIfV4gp7YgJ8B1k=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Gvl/U9ymGmD76EDO8gM1idS4m2xm2nI+zYFCJ02a5UHiKYkdMkYM89OkW7lpaQ7zI kOjq7yrAq+hFHOVpyuqNGqTkvCTKIJGt55YdMDWL1LX3T6SUwB0clNHjiAXtbefSA6 wVZMhfp4HvGIbtEYIpajRqW5OGW4vf/JJyTNLQ6Nc3W7Jps1ujwvQIf/dULCm63oJK om0DQbzTvw2LiMx2QuidllGglTAbWkrVI2d/pJkCrmBt+slX6elHe1Cr1NewXJ++5X BjyTwYkAsKqdRi6sCPJ3kkzYhoNGnlYTIpwCe8dL4DKo+6Kn14Bqikqh9mL6vusfJf HKH0VAw9U0y8w== Date: Mon, 26 Oct 2026 12:12:23 -0700 From: Oliver Upton To: Fuad Tabba Cc: Marc Zyngier , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Raghavendra Rao Ananta , Eric Auger , Will Deacon , Fuad Tabba , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] KVM: arm64: vgic-v4: Don't allocate vPEs for a GICv2 VM Message-ID: References: <20261026152639.3926498-1-fuad.tabba@linux.dev> <20261026152639.3926498-2-fuad.tabba@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261026152639.3926498-2-fuad.tabba@linux.dev> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Oct 26, 2026 at 03:26:38PM +0000, Fuad Tabba wrote: > KVM can run a GICv2 VM on a GICv4.0 host whose CPU interface supports > legacy operation. I'm pretty sure there's no IP out there that has GICv4.0 and legacy mode... > Such a VM has no LPIs and never uses vPEs, so > vgic_supports_direct_irqs() is false for it and kvm_vgic_dist_destroy() > never tears them down. However, userspace can still create an ITS for > it. Once the vgic is initialised, vgic_its_create() calls > vgic_v4_init(), which allocates the vPEs and requests a doorbell IRQ for > each vCPU. They're then never freed, and each doorbell handler stays > registered with a vCPU that's freed with the VM. > > Only allocate vPEs for a GICv3 VM. > > Fixes: 74fe55dc9ab77 ("KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain") > Cc: stable@vger.kernel.org > Signed-off-by: Fuad Tabba > --- > arch/arm64/kvm/vgic/vgic-v4.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c > index ed236f083f0d7..a01de4de608a6 100644 > --- a/arch/arm64/kvm/vgic/vgic-v4.c > +++ b/arch/arm64/kvm/vgic/vgic-v4.c > @@ -248,7 +248,7 @@ int vgic_v4_init(struct kvm *kvm) > > lockdep_assert_held(&kvm->arch.config_lock); > > - if (!kvm_vgic_global_state.has_gicv4) > + if (!kvm_vgic_global_state.has_gicv4 || dist->vgic_model != KVM_DEV_TYPE_ARM_VGIC_V3) use vgic_is_v3() instead Thanks, Oliver > return 0; /* Nothing to see here... move along. */ > > if (dist->its_vm.vpes) > -- > 2.47.3 > >