From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 EC914518138 for ; Tue, 22 Sep 2026 21:42:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790113364; cv=none; b=KN+OI4r0M7NdKVpAjjJ8+diTy6SHRNitZc9K5g0TZsLd/UWUDovmqjQnFirHycsRBhsJwGZGm1m2KjgqonqVhxyoWNGkwL6Zn+VgRupf/e5j2Z0z+IhKK/cp3SBbuU4bS5uCQ+bRHAbKPA0/nDM+HlBppmC44V05mD2Xc+KP6nU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790113364; c=relaxed/simple; bh=wXH79VRe2k3zUfZQYgmqEV6aoX6o24uoOwxSZftwQxI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fL3JKP60HB3n4EL5c1z8VnnncFHxjXYHf98b4v3TwwhqACsH3Z88ale7QA6nrvgdnigox2RWOQKsLiBDHYiUJgBh3XpGw01JpzIAEr7XtvndZSKsBpz0v5R0ZpHXuevd+lkQXGBaRN5S19Ss89sXDU3vWzd7KqhJTBuu1ZcaZu0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZA9IoTuc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZA9IoTuc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C05451F00898; Tue, 22 Sep 2026 21:42:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790113344; bh=WgWgUyqIwCZYbNJUU+AhLYr08CuhiyxlVws3w1/8zMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZA9IoTucmEh77KQE0eJA+F0FHx+KViU90m+ScvETxxmrXWfXCRyvSltp7Xiak3Etz zHQL6jMUh95Am3D0uuHDqvcXwaEZVlYCV3YawJZQzdhtiSXryKn1Ml7EaxwBjIBu7W QMlwMvGdu/Xr4wgDVDrynvabc1psbXd4aosfKYlQC27/5vYz+ded8nk0ou4KtebNwG bAOFw9qZmtKv2GLMpBcgV0PNjuH00pfFLdEgkagc4seMjm7cxSb26vnCbJuURmSg9E 0qq+Ijaifn3wQxwlP6faD34/8vfQh8UkzrKPHVxrskp8u0tRzPm8cZE/7uUAmrLr1X RQPNVPGBOr+MA== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) 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 1x98Fq-0000000CFxJ-3cul; Tue, 22 Sep 2026 21:42:22 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Steffen Eiden , Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Fuad Tabba , Yuchao Zhang Subject: [PATCH 2/3] KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq Date: Tue, 22 Sep 2026 22:42:11 +0100 Message-ID: <20260922214212.3327146-3-maz@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260922214212.3327146-1-maz@kernel.org> References: <20260922214212.3327146-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, seiden@linux.ibm.com, joey.gouly@arm.com, suzuki.poulose@arm.com, oupton@kernel.org, yuzenghui@huawei.com, fuad.tabba@linux.dev, ndaugoing@gmail.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Referencing the last interrupt inserted in an LR is rather fragile, as this interrupt can vanish if a concurrently unmapped LPI. Solve this by bumping up the refcount on the interrupt when populating last_lr_irq, and drop it at vgic_prune_ap_list() time, when LPIs are being reclaimed. Fixes: 6da5e537f5afe ("KVM: arm64: vgic: Pick EOIcount deactivations from AP-list tail") Reported-by: Yuchao Zhang Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org --- arch/arm64/kvm/vgic/vgic.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 425503e0c5825..5cf5a1ef86cdd 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -853,6 +853,17 @@ static void vgic_prune_ap_list(struct kvm_vcpu *vcpu) goto retry; } + /* + * Fix the last_lr_irq refcount which was obtained while + * populating the LRs. This can also result in the LPI being + * deleted. + */ + irq = *host_data_ptr(last_lr_irq); + if (irq) { + deleted_lpis |= vgic_put_irq_norelease(vcpu->kvm, irq); + *host_data_ptr(last_lr_irq) = NULL; + } + raw_spin_unlock(&vgic_cpu->ap_list_lock); if (unlikely(deleted_lpis)) @@ -1018,8 +1029,10 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu) scoped_guard(raw_spinlock, &irq->irq_lock) { if (likely(vgic_target_oracle(irq) == vcpu)) { vgic_populate_lr(vcpu, irq, count++); - if (count == kvm_vgic_global_state.nr_lr) + if (count == kvm_vgic_global_state.nr_lr) { + vgic_get_irq_ref(irq); *host_data_ptr(last_lr_irq) = irq; + } } } -- 2.47.3