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From: Christoph Hellwig <hch@lst.de>
To: Damien Le Moal <dlemoal@kernel.org>
Cc: "Christoph Hellwig" <hch@lst.de>,
	linux-nvme@lists.infradead.org, "Keith Busch" <kbusch@kernel.org>,
	"Sagi Grimberg" <sagi@grimberg.me>,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Kishon Vijay Abraham I" <kishon@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	linux-pci@vger.kernel.org,
	"Rick Wertenbroek" <rick.wertenbroek@gmail.com>,
	"Niklas Cassel" <cassel@kernel.org>
Subject: Re: [PATCH v2 4/5] PCI: endpoint: Add NVMe endpoint function driver
Date: Mon, 14 Oct 2024 13:38:09 +0200	[thread overview]
Message-ID: <20241014113809.GA31551@lst.de> (raw)
In-Reply-To: <79e57ebb-eef7-48b1-b337-845d2ef6ff49@kernel.org>

On Mon, Oct 14, 2024 at 07:41:18PM +0900, Damien Le Moal wrote:
>         |    | PCIe NVMe endpoint driver |     |
> 	|    | (Handles BAR registers,   |     |
> 	|    | doorbells, IRQs, SQs, CQs |     |
> 	|    | and DMA transfers)        |     |
>         |    +---------------------------+     |
>         |                  |                   |
>         |    +---------------------------+     |
>         |    |     NVMe fabrics host     |     |
>         |    +---------------------------+     |

That whole fabrics host here is broken.  The PCI frontend needs to
talk directly to the target code instead of doing a completely
pointless roundtrip through the block layer.

> Unless I am mistaken, if I use a PCI transport as the base for the endpoint
> driver, I would be able to connect only to a PCIe nvme device as the backend, no
> ?

No.  Any fabrisc transport (or frontend) can you any of the the
backends (file / bdev and passthrough).


  reply	other threads:[~2024-10-14 11:38 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-11 12:19 [PATCH v2 0/5] NVMe PCI endpoint function driver Damien Le Moal
2024-10-11 12:19 ` [PATCH v2 1/5] nvmet: rename and move nvmet_get_log_page_len() Damien Le Moal
2024-10-14  6:24   ` Chaitanya Kulkarni
2024-10-11 12:19 ` [PATCH v2 2/5] nvmef: export nvmef_create_ctrl() Damien Le Moal
2024-10-14  6:32   ` Chaitanya Kulkarni
2024-10-14  8:42   ` Christoph Hellwig
2024-10-14  9:10     ` Damien Le Moal
2024-10-14 11:45       ` Christoph Hellwig
2024-10-11 12:19 ` [PATCH v2 3/5] nvmef: Introduce the NVME_OPT_HIDDEN_NS option Damien Le Moal
2024-10-14  8:42   ` Christoph Hellwig
2024-10-14  9:12     ` Damien Le Moal
2024-10-11 12:19 ` [PATCH v2 4/5] PCI: endpoint: Add NVMe endpoint function driver Damien Le Moal
2024-10-14  8:44   ` Christoph Hellwig
2024-10-14 10:41     ` Damien Le Moal
2024-10-14 11:38       ` Christoph Hellwig [this message]
2024-10-11 12:19 ` [PATCH v2 5/5] PCI: endpoint: Document the " Damien Le Moal

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