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 562154E1C92; Tue, 29 Sep 2026 09:36:41 +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=1790674602; cv=none; b=cJjEVjLFhe3qR/YIdL0ATINMrMiufDI1blzvUzseBK+mkY716GLNFI/JVIPh0M7q1WX/aCzL8WUbxwaXlF7kJi4kynF33uqtD5KLiGKKDM1tye2kQH0OL/d/cOYL1pFj4hGW4cW2pxhflce2V5LC5C2fZM+YOLGLMDqXGrencaY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790674602; c=relaxed/simple; bh=wXH79VRe2k3zUfZQYgmqEV6aoX6o24uoOwxSZftwQxI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z9bN+KdjZpD2mM/GabCmdvUHeG88Yyv006zi8UguL1UuAuPZnyWjoaOTrenkOyDObeeEkk451ggFr0z904RJy3USky2yB1wbBHphxS3ZCqmxjWK/DNBbKn9zGSytGCRarVlsFqf6AK+g3ZZ6WBjCbHaXWp1oGYGAArD+VubtDLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YcSjqq4R; 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="YcSjqq4R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 113611F0089B; Tue, 29 Sep 2026 09:36:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790674601; bh=WgWgUyqIwCZYbNJUU+AhLYr08CuhiyxlVws3w1/8zMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YcSjqq4RxJ21ikWGFG6m6KbS8CBC9eeUfwrzCva77FwZ+iwr0+SakAModKOrDq+jj HkOObJJ2EVGrbKZ8W6dbX68rquEJaJir67oPw+M1EvNY8p1iBVeKVLDNRQjWJVCdrX dTWnUUR2rYXuYTNrqZpOYAOgXg8378ITasJbr3R8bMdU0bFkM9ZPLwrsqQHZ6WGnnx 0z1r7ySZwbTHSxDq732p4tA+AcJbrwikN4P9yp5Zzmn+WgeEGYjaP0dijCEkRjuRez e8ge5Nv4D2k4XDZGvrpYZ6GC3Yl6KnY4sDPJlO/lW2FYpwPFDohaGcoSnLlk62wEml fVtoo7Zl1N2tQ== 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 1xBUGN-0000000ElEa-14PP; Tue, 29 Sep 2026 09:36:39 +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 , stable@vger.kernel.org Subject: [PATCH v2 4/7] KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq Date: Tue, 29 Sep 2026 10:35:45 +0100 Message-ID: <20260929093548.3598547-5-maz@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260929093548.3598547-1-maz@kernel.org> References: <20260929093548.3598547-1-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, stable@vger.kernel.org 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