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=1793263539; b=5oDPaFX89cTW+X5+QIfFrHMmOr1jkp7LwGran//+9kbl7vPGyh5mEhmmAFGXTEmZYpVl +Q+q9vKCW2LYXMbtcsDad5uQ554dpQf4YqGzdxAk/zcn0qDrmc94/6IMUCnBRGR5+9QKF OCSOIUxQJTEgYVnf0LxB5h+E889LSDsLG8x4FIDuJeK0kYWuG6UQ3ZPt9UZFd5WLesNhS 84cnzDCyuPTbv9j6ZORCeKJHyou68w62KIG0XgPMAndWhgE0ul2lZYDfq00ACZTj75xtD dZcmT3eOrSLzLeioAM7/hdUgzZdB3pCmyZq2sS3krg49DlHUAT6acpbiYBxlxxexHXQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793263539; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=NN3SS/GWxtehXYYDCzn+wfse+oJraHA6lY5/AzoX8l4=; b=fWDDMA6OS4ooBJPxtNTmeeF/RipGthgdwAHPB6WwOrJtufvTfIaqlzikkEzajChHpRIT LZnKk8o8tCyNgodrjWfZH6HN1uMk4LXhZf8LqUGNpkcvUPYqrlY6vYt69MnPiAcl0P8Uo 8gebate5CKALpHmy1tXzetnLsqy4SC4P7I7fhAhiOVbojmhvBbkduFtYHKSNVA0wbcJVx opsIKDRX73jdJ4bgwSun6F7TvimXOoxwxO4u9qpcxEZ51bOoFZ6v1ukWCkPAZSdKydSx1 PXBTZnnuOQ6K9uRmZuB6LvNENAP8YJDCmE1/KoKorU9G/bjCWcGIPAKbZFkyoR7kkKA== 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=WL0178Kb; 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 B8BA2606A31F for ; Thu, 29 Oct 2026 08:45:38 +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=WL0178Kb Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BAA91F01825; Thu, 29 Oct 2026 08:45:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793263538; bh=NN3SS/GWxtehXYYDCzn+wfse+oJraHA6lY5/AzoX8l4=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=WL0178KbdsynPrEVdm3te3fYp7MyVNzZmrkHyCjgElfP1UeuSm0HuqHUzK7aMf3n4 dCfe9NRKFx53AjwRKGtQpyr9qx0US/lp+2cdI0eMGPhJcKKqK4NYuJeGdO+panFQgQ EqFPgbxdho8NW52HnEmMCOyywdWkpx4FyBAqnzoV1q6f0MFuNRyEL3rie3gqETSM0L 4DTIzTb064S+cKrtj4Zm6Yo19RHWhAupIF8/PYqqTXX7Zgm5TiyUj9YJnqTw9EhYOn 6UihALkWaxke0IReqdf0GIXsf9wB4DZiBp8xu9NaQDK2AE2BfZr+AWf0GR6p+PhuRe T7sahafhAexEw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] 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: <20261029084043.19409-1-zenghui.yu@linux.dev> References: <20261029084043.19409-1-zenghui.yu@linux.dev> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 29 Oct 2026 08:45:37 +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/20261029084043.1940= 9-1-zenghui.yu@linux.dev?part=3D1