From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 ED2ED1367 for ; Sat, 6 Sep 2025 14:22:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757168550; cv=none; b=OwEUP9ObyRZJp+kif4GVktuwdHcS28zDh4NPbWzEm5H01lcbdZTc+yyf43MIKLwwAjwO2VQZ8WzsIK+t3Jy+qbKlKPorZsnf4fTIVDNdOQ+ZrX+TXEJTwTXL0qHE+X2Qd2AH8A3IraBCKiEfTV0EvIc7inM655tCQRcSZS6qT0I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757168550; c=relaxed/simple; bh=C1XB5XhojMXq1JZQGPWQzY6wIFQz2Ud36+ZBWDLRRN4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ps7czujTbZWU0oxr9LzVft2gIdrxPagw2YQNQB8HIEdIwJUSUKeh/1kM5row3dMOK1F9HhMOR7lc1ornfOVwIt/L4udw4kPzB+62IfQEh1khuipLt6RKbl27Ru0j41Opdha8KHlfv5MhgCOKaby8XL/MbzF/eZjfhdGbAs7XqTw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d8gojkH7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="d8gojkH7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1BEBC4CEE7; Sat, 6 Sep 2025 14:22:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757168549; bh=C1XB5XhojMXq1JZQGPWQzY6wIFQz2Ud36+ZBWDLRRN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d8gojkH7B4+uwdGQYzRoSbeaqu7ABNY07MYpaN7GCbpWIl6531O+4TeF/2uk5aAW4 eAYayUgHZ2gEIgl4VVv58py2t+Yr2EmbUlHUZnvbR0NWDSPWZSWyoofe3iC6B7LdTu a45WmAeiTTGoEk6jZQ7NPPl0LanrHgtnxNgioVWHxyKumvc5kA5ZNi0FeOMwq3HKso ZaReqpcCF7gO9vE3oKTpGSKBT5nNKqkyoKS8c+6njEuykKT0Yl16C98m0h5hw3IN1B STAl/7plZrYepAj/oKVHeG0vn1HJg/hLtUou92i9hJArLLeamtJofSXN0/0hHlM8CA 9GI/DWliiTbqA== From: Sasha Levin To: stable@vger.kernel.org Cc: Sean Christopherson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.15.y] KVM: x86: Take irqfds.lock when adding/deleting IRQ bypass producer Date: Sat, 6 Sep 2025 10:22:27 -0400 Message-ID: <20250906142227.32774-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025042806-shrubs-shining-b8f4@gregkh> References: <2025042806-shrubs-shining-b8f4@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sean Christopherson [ Upstream commit f1fb088d9cecde5c3066d8ff8846789667519b7d ] Take irqfds.lock when adding/deleting an IRQ bypass producer to ensure irqfd->producer isn't modified while kvm_irq_routing_update() is running. The only lock held when a producer is added/removed is irqbypass's mutex. Fixes: 872768800652 ("KVM: x86: select IRQ_BYPASS_MANAGER") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Message-ID: <20250404193923.1413163-5-seanjc@google.com> Signed-off-by: Paolo Bonzini [ Adjust context ] Signed-off-by: Sasha Levin --- arch/x86/kvm/x86.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d788d1220a21b..52c59c3bcb91c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12449,16 +12449,22 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons, { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); + struct kvm *kvm = irqfd->kvm; int ret; - irqfd->producer = prod; kvm_arch_start_assignment(irqfd->kvm); + + spin_lock_irq(&kvm->irqfds.lock); + irqfd->producer = prod; + ret = static_call(kvm_x86_update_pi_irte)(irqfd->kvm, prod->irq, irqfd->gsi, 1); - if (ret) kvm_arch_end_assignment(irqfd->kvm); + spin_unlock_irq(&kvm->irqfds.lock); + + return ret; } @@ -12468,9 +12474,9 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, int ret; struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); + struct kvm *kvm = irqfd->kvm; WARN_ON(irqfd->producer != prod); - irqfd->producer = NULL; /* * When producer of consumer is unregistered, we change back to @@ -12478,11 +12484,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, * when the irq is masked/disabled or the consumer side (KVM * int this case doesn't want to receive the interrupts. */ + spin_lock_irq(&kvm->irqfds.lock); + irqfd->producer = NULL; + ret = static_call(kvm_x86_update_pi_irte)(irqfd->kvm, prod->irq, irqfd->gsi, 0); if (ret) printk(KERN_INFO "irq bypass consumer (token %p) unregistration" " fails: %d\n", irqfd->consumer.token, ret); + spin_unlock_irq(&kvm->irqfds.lock); + + kvm_arch_end_assignment(irqfd->kvm); } -- 2.51.0