From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 A02FC2C21E3; Tue, 12 Aug 2025 06:27:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754980050; cv=none; b=ntFX0br/1uqFFi1tpT7se5k36l8Tk3LTkoYoWF6AdiJJQ2xJMmgmJ+hH3ZrNOHd4vPfl9Wb2ZR0nih8Bawtkw/1QUhBnK5/YPQVR2cCV6O3u/4Asl3BNCn8N/tfysH44M/K3M4N9tMD6tQ2OFWloZcjYU21FkT2J+HV8sGkUkKY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754980050; c=relaxed/simple; bh=2zXtN27wOEWwnqIzbf/6hOa52R9QIws6lpKyKqUO4E4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sYmkGoNw4ozPMUC/XupN5eiqZrDs2VNmQR3YAleTtb+BhjRe/64OekKbQ0NeIykRkV5WURwG5ZsTaMucP2N92QLu1U8kdEhpWv7KBRHcKfxpMMXJNh4inKWw30O1dmubEHKotrn7GwuufnB7bhOZ7QhGNEcMWZymPMhy1grIYSw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=YCwjP4zv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=3YZcet6u; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="YCwjP4zv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="3YZcet6u" Date: Tue, 12 Aug 2025 08:27:15 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1754980047; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=IPmlgwTQjbKtST3ioeXe30KnbkE79UAnrUUUOawhgMU=; b=YCwjP4zvmXq9xhFEzhXui7n8JEvZATOJKC61r7qq17HX3j8hgjTzA0kFH2upZpKj3kFswP 4TVxEwLraNI4FAwa7WkfOwYeFdXN57JMQBXBeG1t0kJ5BymFuHIsjhlnZp0krAzCT48EI6 N5WoUwotdGpVxNLhj87zIjELhuYlZ3k12rrw3ERODZKCxmx/UTrZt+3WzEFfnniwrL4HyO bWD5J9aFwdZ6ZEO/evYeLnpd6MfT0n8gU9XON+J/X51vj9fFx5VyLSXv4NQlrewW7YgpuA FVRd0pHJVvH0kkQWXB4Cq7ZdDIQf8U+oeBIyNkBMun1ss+iKx89V4tk9eefEIw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1754980047; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=IPmlgwTQjbKtST3ioeXe30KnbkE79UAnrUUUOawhgMU=; b=3YZcet6uXvR2q2rBg7ocEhSRRGd8fg/sQN2tGHvsMwsT0zdQXQtz/b6kkAZ6AOMzVf873F CQaknr+wMpdsi7Cw== From: Nam Cao To: Bjorn Helgaas Cc: Nirmal Patel , Jonathan Derrick , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Manivannan Sadhasivam , Rob Herring , Bjorn Helgaas , Thomas Gleixner , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Ammar Faizi Subject: Re: [PATCH] PCI: vmd: Remove MSI-X check on child devices Message-ID: <20250812062715.X9TWWWh-@linutronix.de> References: <20250811053935.4049211-1-namcao@linutronix.de> <20250811224659.GA168102@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250811224659.GA168102@bhelgaas> On Mon, Aug 11, 2025 at 05:46:59PM -0500, Bjorn Helgaas wrote: > On Mon, Aug 11, 2025 at 07:39:35AM +0200, Nam Cao wrote: > > Commit d7d8ab87e3e7 ("PCI: vmd: Switch to msi_create_parent_irq_domain()") > > added a WARN_ON sanity check that child devices support MSI-X, because VMD > > document says [1]: > > > > "Intel VMD only supports MSIx Interrupts from child devices and > > therefore the BIOS must enable PCIe Hot Plug and MSIx interrups [sic]." > > Can VMD tell the difference between an incoming MSI MWr transaction > and an MSI-X MWr? > > I wonder if "MSIx" was meant to mean "VMD only supports MSI or MSI-X > interrupts, not INTx interrupts, from child devices"? I don't know, sorry. I am hoping that the VMD maintainers can help us here. But I don't expect to get an answer soon, and this is affecting users, so I prefer to merge it regardless. And to be honest, depending on the answer, this patch may be the wrong fix. But in this worst case, we would just bring the driver back to how it had always behaved, and no one complained before. Therefore it should be safe to do. Nam