Received-SPF: pass (google.com: domain of linux-kernel+bounces-10685-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Date: Sun, 24 Dec 2023 11:32:25 +0100
From: Lukas Wunner <lukas@wunner.de>
To: Ethan Zhao <haifeng.zhao@linux.intel.com>
Cc: bhelgaas@google.com, baolu.lu@linux.intel.com, dwmw2@infradead.org,
	will@kernel.org, robin.murphy@arm.com, linux-pci@vger.kernel.org,
	iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v6 2/4] iommu/vt-d: don's issue devTLB flush request
 when device is disconnected
Message-ID: <20231224103225.GA31197@wunner.de>
References: <20231224050657.182022-1-haifeng.zhao@linux.intel.com>
 <20231224050657.182022-3-haifeng.zhao@linux.intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20231224050657.182022-3-haifeng.zhao@linux.intel.com>
User-Agent: Mutt/1.10.1 (2018-07-13)

On Sun, Dec 24, 2023 at 12:06:55AM -0500, Ethan Zhao wrote:
> --- a/drivers/iommu/intel/pasid.c
> +++ b/drivers/iommu/intel/pasid.c
> @@ -481,6 +481,9 @@ devtlb_invalidation_with_pasid(struct intel_iommu *iommu,
>  	if (!info || !info->ats_enabled)
>  		return;
>  
> +	if (pci_dev_is_disconnected(to_pci_dev(dev)))
> +		return;
> +
>  	sid = info->bus << 8 | info->devfn;
>  	qdep = info->ats_qdep;
>  	pfsid = info->pfsid;

Do you even need this or is patch [4/4] sufficient?
Is there a benefit to the hunk above on top of patch [4/4]?

Thanks,

Lukas