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From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Kiran Kumar <kkokkilagadda@caviumnetworks.com>,
	"ferruh.yigit@intel.com" <ferruh.yigit@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
	"Jacob, Jerin" <Jerin.JacobKollanukkaran@cavium.com>,
	"hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>,
	"jianfeng.tan@intel.com" <jianfeng.tan@intel.com>,
	"Kokkilagadda, Kiran" <Kiran.Kokkilagadda@cavium.com>
Subject: Re: [PATCH] kni: add IOVA va support for kni
Date: Thu, 27 Sep 2018 11:58:09 +0100
Message-ID: <ca763cd6-adcc-1d07-321c-80b6a87f6128@intel.com> (raw)
In-Reply-To: <20180927104846.16356-1-kkokkilagadda@caviumnetworks.com>

On 27-Sep-18 11:49 AM, Kiran Kumar wrote:
> With current KNI implementation kernel module will work only in
> IOVA=PA mode. This patch will add support for kernel module to work
> with IOVA=VA mode.
> 
> The idea is to maintain a mapping in KNI module between user pages and
> kernel pages and in fast path perform a lookup in this table and get
> the kernel virtual address for corresponding user virtual address.
> 
> In IOVA=VA mode, the memory allocated to the pool is physically
> and virtually contiguous. We will take advantage of this and create a
> mapping in the kernel.In kernel we need mapping for queues
> (tx_q, rx_q,... slow path) and mbuf memory (fast path).
> 
> At the KNI init time, in slow path we will create a mapping for the
> queues and mbuf using get_user_pages similar to af_xdp. Using pool
> memory base address, we will create a page map table for the mbuf,
> which we will use in the fast path for kernel page translation.
> 
> At KNI init time, we will pass the base address of the pool and size of
> the pool to kernel. In kernel, using get_user_pages API, we will get
> the pages with size PAGE_SIZE and store the mapping and start address
> of user space in a table.
> 
> In fast path for any user address perform PAGE_SHIFT
> (user_addr >> PAGE_SHIFT) and subtract the start address from this value,
> we will get the index of the kernel page with in the page map table.
> Adding offset to this kernel page address, we will get the kernel address
> for this user virtual address.
> 
> For example user pool base address is X, and size is S that we passed to
> kernel. In kernel we will create a mapping for this using get_user_pages.
> Our page map table will look like [Y, Y+PAGE_SIZE, Y+(PAGE_SIZE*2) ....]
> and user start page will be U (we will get it from X >> PAGE_SHIFT).
> 
> For any user address Z we will get the index of the page map table using
> ((Z >> PAGE_SHIFT) - U). Adding offset (Z & (PAGE_SIZE - 1)) to this
> address will give kernel virtual address.
> 
> Signed-off-by: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
> ---

<snip>

> +
> +	/* IOVA mode. 1 = VA, 0 = PA */
> +	uint8_t iova_mode;

Wouldn't it be easier to understand if the same values (e.g. iova_mode 
== RTE_IOVA_VA) were used here as they are in DPDK?

-- 
Thanks,
Anatoly

  reply index

Thread overview: 103+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-27 10:49 Kiran Kumar
2018-09-27 10:58 ` Burakov, Anatoly [this message]
2018-10-02 17:05 ` Ferruh Yigit
2019-04-01 17:30   ` Jerin Jacob Kollanukkaran
2019-04-01 18:20     ` Ferruh Yigit
2019-04-01  9:51 ` [PATCH v2] " Kiran Kumar Kokkilagadda
2019-04-03 16:29   ` Ferruh Yigit
2019-04-04  5:03     ` [dpdk-dev] [EXT] " Kiran Kumar Kokkilagadda
2019-04-04 11:20       ` Ferruh Yigit
2019-04-04 13:29         ` Burakov, Anatoly
2019-04-04  9:57     ` Burakov, Anatoly
2019-04-04 11:21       ` Ferruh Yigit
2019-04-16  4:55   ` [dpdk-dev] [PATCH v3] " kirankumark
2019-04-19 10:38     ` Thomas Monjalon
2019-04-22  4:39     ` [dpdk-dev] [PATCH v4] " kirankumark
2019-04-22  6:15       ` [dpdk-dev] [PATCH v5] " kirankumark
2019-04-26  9:11         ` Burakov, Anatoly
2019-06-25  3:56         ` [dpdk-dev] [PATCH v6 0/4] add IOVA = VA support in KNI vattunuru
2019-06-25  3:56           ` [dpdk-dev] [PATCH v6 1/4] lib/mempool: skip populating mempool objs that falls on page boundaries vattunuru
2019-06-25  3:56           ` [dpdk-dev] [PATCH v6 2/4] lib/kni: add PCI related information vattunuru
2019-06-25 17:41             ` Stephen Hemminger
2019-06-26  3:48               ` [dpdk-dev] [EXT] " Vamsi Krishna Attunuru
2019-06-26 14:58                 ` Stephen Hemminger
2019-06-27  9:43                   ` Vamsi Krishna Attunuru
2019-07-11 16:22             ` [dpdk-dev] " Ferruh Yigit
2019-07-12 11:02               ` [dpdk-dev] [EXT] " Vamsi Krishna Attunuru
2019-07-12 11:11                 ` Ferruh Yigit
2019-06-25  3:56           ` [dpdk-dev] [PATCH v6 3/4] example/kni: add IOVA support for kni application vattunuru
2019-07-11 16:23             ` Ferruh Yigit
2019-06-25  3:57           ` [dpdk-dev] [PATCH v6 4/4] kernel/linux/kni: add IOVA support in kni module vattunuru
2019-07-11 16:30             ` Ferruh Yigit
2019-07-12 10:38               ` [dpdk-dev] [EXT] " Vamsi Krishna Attunuru
2019-07-12 11:10                 ` Ferruh Yigit
2019-07-12 12:27                   ` Vamsi Krishna Attunuru
2019-07-12 16:29                   ` Vamsi Krishna Attunuru
2019-07-15 11:26                     ` Ferruh Yigit
2019-07-15 13:06                       ` Vamsi Krishna Attunuru
2019-07-11 16:43             ` [dpdk-dev] " Stephen Hemminger
2019-06-25 10:00           ` [dpdk-dev] [PATCH v6 0/4] add IOVA = VA support in KNI Burakov, Anatoly
2019-06-25 11:15             ` Jerin Jacob Kollanukkaran
2019-06-25 11:30               ` Burakov, Anatoly
2019-06-25 13:38                 ` Burakov, Anatoly
2019-06-27  9:34                   ` Jerin Jacob Kollanukkaran
2019-07-01 13:51                     ` Vamsi Krishna Attunuru
2019-07-04  6:42                       ` Vamsi Krishna Attunuru
2019-07-04  9:48                         ` Jerin Jacob Kollanukkaran
2019-07-11 16:21                           ` Ferruh Yigit
2019-07-17  9:04           ` [dpdk-dev] [PATCH v7 0/4] kni: add IOVA=VA support vattunuru
2019-07-17  9:04             ` [dpdk-dev] [PATCH v7 1/4] mempool: modify mempool populate() to skip objects from page boundaries vattunuru
2019-07-17 13:36               ` Andrew Rybchenko
2019-07-17 13:47                 ` Olivier Matz
2019-07-17 17:31                 ` Vamsi Krishna Attunuru
2019-07-18  9:28                   ` Andrew Rybchenko
2019-07-18 14:16                     ` Vamsi Krishna Attunuru
2019-07-19 13:38                       ` [dpdk-dev] [RFC 0/4] mempool: avoid objects allocations across pages Olivier Matz
2019-07-19 13:38                         ` [dpdk-dev] [RFC 1/4] mempool: clarify default populate function Olivier Matz
2019-07-19 15:42                           ` Andrew Rybchenko
2019-07-19 13:38                         ` [dpdk-dev] [RFC 2/4] mempool: unalign size when calculating required mem amount Olivier Matz
2019-08-07 15:21                           ` [dpdk-dev] ***Spam*** " Andrew Rybchenko
2019-07-19 13:38                         ` [dpdk-dev] [RFC 3/4] mempool: introduce function to get mempool page size Olivier Matz
2019-08-07 15:21                           ` Andrew Rybchenko
2019-07-19 13:38                         ` [dpdk-dev] [RFC 4/4] mempool: prevent objects from being across pages Olivier Matz
2019-07-19 14:03                           ` Burakov, Anatoly
2019-07-19 14:11                           ` Burakov, Anatoly
2019-08-07 15:21                           ` Andrew Rybchenko
2019-07-23  5:37                         ` [dpdk-dev] [RFC 0/4] mempool: avoid objects allocations " Vamsi Krishna Attunuru
2019-08-07 15:21                         ` [dpdk-dev] ***Spam*** " Andrew Rybchenko
2019-07-17  9:04             ` [dpdk-dev] [PATCH v7 2/4] kni: add IOVA = VA support in KNI lib vattunuru
2019-07-17  9:04             ` [dpdk-dev] [PATCH v7 3/4] kni: add IOVA=VA support in KNI module vattunuru
2019-07-17  9:04             ` [dpdk-dev] [PATCH v7 4/4] kni: modify IOVA mode checks to support VA vattunuru
2019-07-23  5:38             ` [dpdk-dev] [PATCH v8 0/5] kni: add IOVA=VA support vattunuru
2019-07-23  5:38               ` [dpdk-dev] [PATCH v8 1/5] mempool: populate mempool with page sized chunks of memory vattunuru
2019-07-23 11:08                 ` Andrew Rybchenko
2019-07-23 12:28                   ` Vamsi Krishna Attunuru
2019-07-23 19:33                     ` Andrew Rybchenko
2019-07-24  7:09                       ` Vamsi Krishna Attunuru
2019-07-24  7:27                         ` Andrew Rybchenko
2019-07-29  6:25                           ` Vamsi Krishna Attunuru
2019-07-23  5:38               ` [dpdk-dev] [PATCH v8 2/5] add IOVA -VA support in KNI lib vattunuru
2019-07-23 10:54                 ` Andrew Rybchenko
2019-07-23  5:38               ` [dpdk-dev] [PATCH v8 3/5] kni: add app specific mempool create & free routine vattunuru
2019-07-23 10:50                 ` Andrew Rybchenko
2019-07-23 11:01                   ` Vamsi Krishna Attunuru
2019-07-23  5:38               ` [dpdk-dev] [PATCH v8 4/5] kni: add IOVA=VA support in KNI module vattunuru
2019-07-23  5:38               ` [dpdk-dev] [PATCH v8 5/5] kni: modify IOVA mode checks to support VA vattunuru
2019-07-24  7:14               ` [dpdk-dev] [PATCH v8 0/5] kni: add IOVA=VA support Vamsi Krishna Attunuru
2019-07-29 12:13               ` [dpdk-dev] [PATCH v9 " vattunuru
2019-07-29 12:13                 ` [dpdk-dev] [PATCH v9 1/5] mempool: populate mempool with the page sized chunks of memory vattunuru
2019-07-29 12:41                   ` Andrew Rybchenko
2019-07-29 13:33                     ` [dpdk-dev] [EXT] " Vamsi Krishna Attunuru
2019-08-16  6:12                   ` [dpdk-dev] [PATCH v10 0/5] kni: add IOVA=VA support vattunuru
2019-08-16  6:12                     ` [dpdk-dev] [PATCH v10 1/5] mempool: populate mempool with the page sized chunks vattunuru
2019-08-16  6:12                     ` [dpdk-dev] [PATCH v10 2/5] kni: add IOVA=VA support in KNI lib vattunuru
2019-08-16  6:12                     ` [dpdk-dev] [PATCH v10 3/5] kni: add app specific mempool create and free routines vattunuru
2019-08-16  6:12                     ` [dpdk-dev] [PATCH v10 4/5] kni: add IOVA=VA support in KNI module vattunuru
2019-08-16  6:12                     ` [dpdk-dev] [PATCH v10 5/5] kni: modify IOVA mode checks to support VA vattunuru
2019-07-29 12:13                 ` [dpdk-dev] [PATCH v9 2/5] kni: add IOVA=VA support in KNI lib vattunuru
2019-07-29 12:24                   ` Igor Ryzhov
2019-07-29 13:22                     ` [dpdk-dev] [EXT] " Vamsi Krishna Attunuru
2019-07-29 12:13                 ` [dpdk-dev] [PATCH v9 3/5] kni: add app specific mempool create & free routine vattunuru
2019-07-29 12:13                 ` [dpdk-dev] [PATCH v9 4/5] kni: add IOVA=VA support in KNI module vattunuru
2019-07-29 12:13                 ` [dpdk-dev] [PATCH v9 5/5] kni: modify IOVA mode checks to support VA vattunuru
2019-04-23  8:56       ` [dpdk-dev] [PATCH v4] kni: add IOVA va support for kni Burakov, Anatoly

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