From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.73 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793182416; b=EqphwvweTkYyNWjuyqVlV8niWHn/YUikRNt1z0s9Abtduy/YuQg2qAoLZKLBd8GWkoD2 kK0glpCB+qfPQmMzoUXeF4Q3k83ePqykEday0dx5c06pB6oO/pd3IZWP3QawCm7eVy3aw jEPOAWlkPsNjW0+AqfG/7WKkoCsEoFl+7IjmrWUm9Jc4v4iyrzwpr+ofiKraMct+SDAVA HKW4azjolxOQd9RpnM4yJNlSwmmVV9dQ3iYzzszeobc0X4zMK+hkp6PKAHkOu5n52w5bf ymbG/co2T8izvknkl3yzzi65mDk2Tlc8hB9Z+bKOq8FHBcgPzQVmgoWy9rl6r62aPAA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793182416; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=5NABG2AiXntzQQhgrbFs5uOv8MiJIKrNTvyQWAjpfGM=; b=r5pbaSmFuOZPLUYeDhihqIchXm/aCKGsn9PadnCP2+ZkcS7fk+Fj4tzpKM0x47YatO3a sqQ9R3jJZLNTdxT5t2i+4G/yldvSzwhcZqtKYzIYpdcmMXaU9mZuxy7B+jvRnwCZrhJG4 jOHpebulebiFZPrGPbqiqhU9pwTu6rbtKqdrrXWI1ETNCrb4ncFWrNdOeoMqdJ6Yiwe68 96Ufmp9IDOLXBQF+oql1RMMo/5tP9QUlVRRpVm2BsmSmPXWNEDQUtJ/oSOVk51kNOKIkA UUTmoQvoMg4RMhNeDpBmwgxcmq2RfD7QjrabJFeZd8zwRwuEfzkqVhJISgoDHXniKMg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=j64q8qUb; arc=none smtp.remote-ip=91.218.175.73 Received: from mta0.migadu.com (out-73.mta0.migadu.com [91.218.175.73]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48609606A31C for ; Wed, 28 Oct 2026 10:13:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 48609606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=j64q8qUb X-Envelope-To: kvmarm@lists.linux.dev DKIM-Signature: a=rsa-sha256; bh=kg3kdJ38Ft3AD46ZxOYLXC0C0yujn9suVYw9Z8g/U9Y=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793182414; v=1; x=1793787214; b=j64q8qUbnIImZVnnR94EjYfCqijHtVApq4tBd9c7UecgpowHQdKQ0YVAzh/473sxqNm+N3Eb RgxM1RTMOfqkd17Ph5ETyzwZ4fygmIS+uFy56vYlIutGl2koa4ScNG4rNMHmaUpq29QVVBRNvmq j1kUINqeL81wTs9XPrBqc1Zs= X-Envelope-To: kvmarm@lists.linux.dev Received: by smtp.migadu.com with ESMTPS id 8e770c70f83dabeb; Wed, 28 Oct 2026 10:13:34 +0000 X-Mizu-Trace-ID: 8e770c70f83dabeb X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton Cc: Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Raghavendra Rao Ananta , Eric Auger , Sascha Bischoff , Will Deacon , Fuad Tabba , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] KVM: arm64: vgic-v4: Don't allocate vPEs when userspace clears nASSGIcap Date: Wed, 28 Oct 2026 10:13:18 +0000 Message-ID: <20261028101318.2170928-3-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261028101318.2170928-1-fuad.tabba@linux.dev> References: <20261028101318.2170928-1-fuad.tabba@linux.dev> X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since commit c652887a92887 ("KVM: arm64: vgic-v3: Allow userspace to write GICD_TYPER2.nASSGIcap"), userspace can disable vPE allocation for a VM on a GICv4.1 host with vSGIs by clearing nASSGIcap before the vgic is initialised. vgic_init() then skips vgic_v4_init(), and kvm_vgic_dist_destroy() skips vgic_v4_teardown(). vgic_its_create() still calls vgic_v4_init() for an ITS created after the vgic is initialised, though, and vgic_v4_init() allocates the vPEs and requests a doorbell IRQ for each vCPU. Destroying the VM leaks them, and leaves each doorbell handler registered with a vCPU that's about to be freed. Move the part of vgic_supports_direct_msis() that doesn't depend on the ITS into vgic_supports_vpes(), together with vgic_v4_init()'s GICv3 check. Gate vgic_v4_init() on it rather than on vgic_supports_direct_irqs(), which reads has_its before vgic_its_create() sets it. vgic_supports_direct_msis() returns what it did before, since vgic_has_its() is already false for a non-GICv3 VM. Fixes: c652887a92887 ("KVM: arm64: vgic-v3: Allow userspace to write GICD_TYPER2.nASSGIcap") Suggested-by: Oliver Upton Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba --- arch/arm64/kvm/vgic/vgic-mmio-v3.c | 9 +++++++-- arch/arm64/kvm/vgic/vgic-v4.c | 2 +- arch/arm64/kvm/vgic/vgic.h | 1 + 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index 5913a20d83019..a60697238a7a7 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -48,7 +48,7 @@ bool vgic_has_its(struct kvm *kvm) return dist->has_its; } -bool vgic_supports_direct_msis(struct kvm *kvm) +bool vgic_supports_vpes(struct kvm *kvm) { /* * Deliberately conflate vLPI and vSGI support on GICv4.1 hardware, @@ -58,7 +58,12 @@ bool vgic_supports_direct_msis(struct kvm *kvm) if (system_supports_direct_sgis() && !vgic_supports_direct_sgis(kvm)) return false; - return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm); + return kvm_vgic_global_state.has_gicv4 && vgic_is_v3(kvm); +} + +bool vgic_supports_direct_msis(struct kvm *kvm) +{ + return vgic_supports_vpes(kvm) && vgic_has_its(kvm); } bool system_supports_direct_sgis(void) diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c index a01de4de608a6..0a4b9a74425b4 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 || dist->vgic_model != KVM_DEV_TYPE_ARM_VGIC_V3) + if (!vgic_supports_vpes(kvm)) return 0; /* Nothing to see here... move along. */ if (dist->its_vm.vpes) diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index b71d486ae5145..7fc29a395a7db 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -500,6 +500,7 @@ static inline bool vgic_host_has_gicv5(void) } bool system_supports_direct_sgis(void); +bool vgic_supports_vpes(struct kvm *kvm); bool vgic_supports_direct_msis(struct kvm *kvm); bool vgic_supports_direct_sgis(struct kvm *kvm); -- 2.47.3