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Date: Fri, 27 Feb 2026 14:37:05 -0700
From: Keith Busch <kbusch@kernel.org>
To: Leon Romanovsky <leon@kernel.org>
Cc: Saeed Mahameed <saeedm@nvidia.com>, Tariq Toukan <tariqt@nvidia.com>,
	Mark Bloch <mbloch@nvidia.com>, Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Jason Gunthorpe <jgg@ziepe.ca>, linux-rdma@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Maher Sanalla <msanalla@nvidia.com>
Subject: Re: [PATCH rdma-next 0/6] Add support for TLP emulation
Message-ID: <aaIOgcfCbRIBlpUO@kbusch-mbp>
References: <20260225-var-tlp-v1-0-fe14a7ac7731@nvidia.com>
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In-Reply-To: <20260225-var-tlp-v1-0-fe14a7ac7731@nvidia.com>

On Wed, Feb 25, 2026 at 04:19:30PM +0200, Leon Romanovsky wrote:
> This series adds support for Transaction Layer Packet (TLP) emulation
> response gateway regions, enabling userspace device emulation software
> to write TLP responses directly to lower layers without kernel driver
> involvement.
> 
> Currently, the mlx5 driver exposes VirtIO emulation access regions via
> the MLX5_IB_METHOD_VAR_OBJ_ALLOC ioctl. This series extends that
> ioctl to also support allocating TLP response gateway channels for
> PCI device emulation use cases.

Sorry if this is obvious to people in the know, but could you possibly
give a quick high level description of the use case behind this feature?
I'm just curious what emulation needs are enabled by having access to
this packet level. Thanks!