From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E554113A3F2; Wed, 9 Jul 2025 04:42:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752036137; cv=none; b=eTlKakylPlejzXQ15McUBMLfBs3cVpcDnJlWJOoHpMU08/9rHZy5C/ffPpi9pdUyCNJR2jaUmwmrfSMTVoZdZ49Y9QJDLZJv488rbxmD6fm5nJ2FT16SiPm9PgZ96EuCwZmtq44umquhjG4MgH88QpTpsnG8klDPFGuATa0NKGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752036137; c=relaxed/simple; bh=Fn21aLk8KOVq18tlx6uiN1yIKZDUgjxrdNQzKFjWHZo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rS7xKIxJRmnVt/LB08BmhUV8IBwQW1KALIF8JFGCHsHrr/j6kjNziW8G73cO3wm0bQTwtadrklXcT+ZK8TlbJNRcVh+Py0HSwZ9HAMhXStJ+HLKRcnsunPR5urm68zeteJnhoRhEQJ0/gL81T+VQIFWxiTVEZt70EW71ZodlY/c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=TYlwDQDr; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="TYlwDQDr" Received: from [100.79.218.70] (unknown [4.194.122.136]) by linux.microsoft.com (Postfix) with ESMTPSA id 629D9201B1AE; Tue, 8 Jul 2025 21:42:12 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 629D9201B1AE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1752036135; bh=0OdFxV7TyZBPInyMjkfna2ntk1j8yOVcJaUIxoV+hLA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TYlwDQDrC8u9N4j5ib7rMwBKMQWHAH2JmrCB/O9SG/ozV8WYCCPcTYW2yisUWq84l HNRPHeZJDrc67ktZFfz+KITRkkDmsgHZworX0yo2yCnCTAgmv2dFtyEBVMLGlkvyQM W1DDF1b91bUnfc7NZ7lUH7Tu7U/fBvv+ZVXHLPPk= Message-ID: <34d1f7e4-0729-4faf-95b7-e2fce6c3be2e@linux.microsoft.com> Date: Wed, 9 Jul 2025 10:12:09 +0530 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] PCI/MSI: Initialize the prepare descriptor by default To: Bjorn Helgaas Cc: Shradha Gupta , Bjorn Helgaas , Thomas Gleixner , Marc Zyngier , Lorenzo Pieralisi , Shivamurthy Shastri , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, Roman Kisel References: <20250708160817.GA2148355@bhelgaas> Content-Language: en-US From: Naman Jain In-Reply-To: <20250708160817.GA2148355@bhelgaas> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/8/2025 9:38 PM, Bjorn Helgaas wrote: > On Tue, Jul 08, 2025 at 03:45:05PM +0530, Naman Jain wrote: >> On 7/8/2025 3:32 PM, Shradha Gupta wrote: >>> On Tue, Jul 08, 2025 at 10:48:48AM +0530, Naman Jain wrote: >>>> Plug the default MSI-X prepare descriptor for non-implemented ops by >>>> default to workaround the inability of Hyper-V vPCI module to setup >>>> the MSI-X descriptors properly; especially for dynamically allocated >>>> MSI-X. >>>> >>>> Signed-off-by: Naman Jain >>>> --- >>>> drivers/pci/msi/irqdomain.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c >>>> index 765312c92d9b..655e99b9c8cc 100644 >>>> --- a/drivers/pci/msi/irqdomain.c >>>> +++ b/drivers/pci/msi/irqdomain.c >>>> @@ -84,6 +84,8 @@ static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info) >>>> } else { >>>> if (ops->set_desc == NULL) >>>> ops->set_desc = pci_msi_domain_set_desc; >>>> + if (ops->prepare_desc == NULL) >>>> + ops->prepare_desc = pci_msix_prepare_desc; >>>> } >>>> } >>>> >>>> base-commit: 26ffb3d6f02cd0935fb9fa3db897767beee1cb2a >>>> -- >>>> 2.34.1 >>>> >>> >>> Hey Naman, >>> >>> can you please try your tests with this patch: >>> https://lore.kernel.org/all/1749651015-9668-1-git-send-email-shradhagupta@linux.microsoft.com/ >>> I think this should help your use case >> >> Hey, >> Thanks for sharing this, this works for me. >> >> Closing this thread. > > I guess this means we should ignore this patch? If it turns out that > we do need this patch, I'd like to add some details in the commit log > about what this problem looks like to users. > > Bjorn Yes, my patch is no longer required, since it was doing the same thing that Shradha's patch (1-2) were doing, but in a different way. Shradha's patch is better and would suffice for the use case. Please ignore this patch. Thanks. Regards, Naman