From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793041945; b=hHB2UlH9d4vxWd/6WROwTgTJROcWnEveRZi7/s/ukyM5th0XY0XXdZUqC57E2+Dt6NW8 xKFOOBqSJlZMPgFOKEB+XWUIGaxL+9LR7EoKarcwc69Jbr/fB860jgCPLvhiodL/hBvfY AWb4LleLvTvTdf7bXo6J2i8CBsITurx+neQ9NGVoZQ+kfbDVcNG2t5yrWRagXP8Onyula 5UW2b7kh5m3YJjiTy1qzulQlAnwd35S15k3Mue3NV7zZJReSH4GZMyBD91HJs8Vm+FOI3 7QqCzdn07GOzzRkmx7Cd1ULUtNg/NFcgQWAZQDfNknIMme5tyihj+hl1et7/v4sUujA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793041945; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=/xdSDdeNwO4oLUk3isMtVnIVH6TEXIfV4gp7YgJ8B1k=; b=iqrnissL9EU6rS3eDWY0njWKiiZ21gQixvMQWwwTB0q0G0YPJd3pfPw7awLE88dcgw5c I5w8q7+AoKOYoNK7AAQK6Ciuw8M91w7SSPENDnqLfTov7n8uc32TYObi1nmxvejfw10Yc +ttMDFIKZfC5mExtrdEWPsB7u8GDAkxdN6vz44/lEZbd3hb+xuJ+rzB9289eEpK15xsp9 gbWdkM3VOzcI/okSCngmDEOcZaSqKDESUaUjfuxioE6/yLjT1+dybCd9Zs7M90FYhDGy4 Zj+wqQOHHg0j9QMby9L+yQurMT+ajveKyq9eA7iJ5/JeE1eckMzm6RZunPrt2FM0cKQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="Gvl/U9ym"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C642606A31D; Mon, 26 Oct 2026 19:12:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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 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-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261026152639.3926498-2-fuad.tabba@linux.dev> 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 > >