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=1793276498; b=rxqCjhA1nhljJe5x1xcpTLNbEHFLhd27n/0jUSqdl3vvFdHGqYwnUOKJfx8iBB8zIfj1 z7gnE3yqdL0fwgXbcarAbemeo1e+jv0ao2pNMrOa2qQMbKg1TGv5P15yHSf6amlreablw KGEOhbl2oUwPhKMr6WoeT8CVD6C+tJzkgbiQ6oE6EN/aETsv6tm2hvjKLUtFPOZj9EGWr oNDurLlAuaeRvZxuXeYfE+VtzmbNZwslFHCidVNb/KHZkT0eBHJYAgw3eWyOAl2dZ7ApD jpio7z/lYBVqahjGRntJP6yxUVHfZyGS7DjWufKjPs7QXiKOBVPvB3/SX1g82NOm04g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793276498; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=76B8w5iLKCPxfLJXd3X043vq9OsdC3dWqLya7FBe1xw=; b=hDxPKReAdcP16rePKcl3oSLAGPwfmqLJQ+xZzwwJKvLOkDodhx8nSXaWYpRHmGXgnNaf ItrZqZB7ImJRLC99B0OxV45hEphxkM8WT7/cLuy1nWuUHkYjywvzS9dDYdw+Or9OSu83L uQxgmEVkwYgbxgcV90R4BVi36WHRzzMKSkNYT1AnZQaxAp6o0gTAAd0aIZm0j0z3CRYon swyDhvKwV8gWa8Vm9fpORL4e3MlMA3+Ch7Sydb0jTBzmMqQoZrcU7cYnd6YSrBaTz+G0w FLDNk1HzSTXJOApe95P8oLUbxwkwF3PDiF+KdnHaQbXh+PzUtkDtkfOGwfjxgFn+NzA== 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=QsPSWwLj; 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 06194606A31A for ; Thu, 29 Oct 2026 12:21:37 +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=QsPSWwLj Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88ECD1F01825; Thu, 29 Oct 2026 12:21:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793276497; bh=76B8w5iLKCPxfLJXd3X043vq9OsdC3dWqLya7FBe1xw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=QsPSWwLjxXEe3+nyrM/PXDOkyIaKIXNZByMlPIeBv9DuAio10vm8IEC7fE3CACoJB DPQHrJPinmE/l1669kPayUeBceKVFCivgkJlMN29zl55762xkNvDRm4O8at1XN9snG GvigjRWa94LbqrCOOH08UHehqM4I5qQPPD8c3RfYubO+HjP/t2xjvZcMctcYUlWqJB fogUm9vj8pe5e4pTnwt2LCGWUxd2R99PZWiPfcF65I6aOQ9DUFDXKfx+CLSEHKXUi1 Kj9V8ffGlW4+54z5JQ++Scf7IOs7gy4N41FaQzG71nzQWU3MZl9w66AVYd00KtiIUz 4NKkErXNYWt2w== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2] virtio_pci: don't take the MSI mutex under cpu_hotplug_lock Reply-To: sashiko-reviews@lists.linux.dev To: "Zenghui Yu" , virtualization@lists.linux.dev Cc: "Michael S. Tsirkin" , "Eugenio Perez" In-Reply-To: <20261029121648.22155-1-zenghui.yu@linux.dev> References: <20261029121648.22155-1-zenghui.yu@linux.dev> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 29 Oct 2026 12:21:37 +0000 X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: "Zenghui Yu (Huawei)" >=20 > Lockdep reports the following circular locking dependency when a virtio-n= et > device is probed with lockdep enabled on a system whose devices sit behind > an IOMMU: >=20 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D > WARNING: possible circular locking dependency detected > 7.3.0-rc1+ #84 Not tainted > ------------------------------------------------------ > kworker/u34:0/57 is trying to acquire lock: > ffff800104f83ee8 (&md->mutex){+.+.}-{4:4}, at: msi_domain_get_virq+0x= f0/0x118 >=20 > but task is already holding lock: > ffffc00081edd930 (cpu_hotplug_lock){++++}-{0:0}, at: cpus_read_lock+0= x10/0x1c > [ ... ] > This also covers the CPU hotplug callbacks > (virtnet_cpu_online/virtnet_cpu_dead), which call virtnet_set_affinity() > with cpu_hotplug_lock already held. >=20 > Signed-off-by: Zenghui Yu (Huawei) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261029121648.2215= 5-1-zenghui.yu@linux.dev?part=3D1