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From: "谢华伟(此时此刻)" <huawei.xhw@alibaba-inc.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>, ferruh.yigit@intel.com
Cc: dev@dpdk.org, anatoly.burakov@intel.com,
	david.marchand@redhat.com, zhihong.wang@intel.com,
	chenbo.xia@intel.com, grive@u256.net
Subject: Re: [dpdk-dev] [PATCH v5 0/3] support both PIO and MMIO BAR for virtio PMD
Date: Fri, 15 Jan 2021 02:19:47 +0800
Message-ID: <6b05b2b3-7616-f121-d827-67a2b25c641b@alibaba-inc.com> (raw)
In-Reply-To: <d9092fdf-6149-4338-f861-ba728773ce05@redhat.com>


On 2021/1/13 1:37, Maxime Coquelin wrote:
>
> On 10/22/20 5:51 PM, 谢华伟(此时此刻) wrote:
>> From: "huawei.xhw" <huawei.xhw@alibaba-inc.com>
>>
>> Legacy virtio-pci only supports PIO BAR resource. As we need to create lots of
>> virtio devices and PIO resource on x86 is very limited, we expose MMIO BAR.
>>
>> Kernel supports both PIO  and MMIO BAR for legacy virtio-pci device. We handles
>> different type of BAR in the similar way.
>>
>> In previous implementation, with igb_uio we get PIO address from igb_uio
>> sysfs entry; with uio_pci_generic, we get PIO address from
>> /proc/ioports.
>> For PIO/MMIO RW, there is different path for different drivers and arch.
>> For VFIO, PIO/MMIO RW is through syscall, which has big performance
>> issue.
> Regarding the performance issue, do you have some numbers to share?
> AFAICS, it can only have an impact on performance when interrupt mode is
> used or queue notification is enabled.

I didn't have performance number, but would do it when have time.

Yes, it is not needed when virtio backend/device is working in polling mode.

But anyway, ioctl isn't needed at all.

/huawei

>
> Does your HW Virtio implementation requires notification?
>
> Is performance the only issue to have your HW working with Virtio PMD,
> or is this series also fixing some functionnal issues?

There is two purpose with this patch. One is to support MMIO, and the 
other is to

unify/simplify the way to get IO/MMIO resource and read/write IO/MMIO 
port for virtio PMD.

Current implementation is too complicated.

/huawei

>
> Best regards,
> Maxime



>> On X86, it assumes only PIO is supported.
>>
>> All of the above is too much twisted.
>> This patch unifies the way to get both PIO and MMIO address for different driver
>> and arch, all from standard resource attr under pci sysfs.
>>
>> We distinguish PIO and MMIO by their address like how kernel does. It is ugly but works.
>>
>> v2 changes:
>> 	 - add more explanation in the commit message
>>
>> v3 changes:
>> 	 - fix patch format issues
>>
>> v4 changes:
>> 	 - fixes for RTE_KDRV_UIO_GENERIC -> RTE_PCI_KDRV_UIO_GENERIC
>>
>> v5 changes:
>> 	 - split into three seperate patches
>>
>> huawei.xhw (3):
>>    PCI: use PCI standard sysfs entry to get PIO address
>>    PCI: support MMIO in rte_pci_ioport_map/unap/read/write
>>    PCI: don't use vfio ioctl call to access PIO resource
>>
>>   drivers/bus/pci/linux/pci.c     |  89 +-------------------
>>   drivers/bus/pci/linux/pci_uio.c | 177 ++++++++++++++++++++++++++++------------
>>   2 files changed, 128 insertions(+), 138 deletions(-)
>>

  reply	other threads:[~2021-01-14 18:20 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-30 14:59 [dpdk-dev] [PATCH v2] pci: support both PIO and MMIO BAR for legacy virtio on x86 谢华伟(此时此刻)
2020-10-01 10:22 ` Burakov, Anatoly
2020-10-02  5:44   ` 谢华伟(此时此刻)
2020-10-09  8:36 ` [dpdk-dev] [PATCH v3] " 谢华伟(此时此刻)
2020-10-13  8:41 ` [dpdk-dev] [PATCH v4] support both PIO and MMIO bar for virtio pci device 谢华伟(此时此刻)
2020-10-13  8:41   ` [dpdk-dev] [PATCH v4] pci: support both PIO and MMIO BAR for legacy virtio on x86 谢华伟(此时此刻)
2020-10-13 12:34     ` 谢华伟(此时此刻)
2020-10-21  8:46     ` 谢华伟(此时此刻)
2020-10-21 11:49     ` Ferruh Yigit
2020-10-21 12:32       ` 谢华伟(此时此刻)
2020-10-21 17:24         ` Ferruh Yigit
2020-10-22  9:15           ` 谢华伟(此时此刻)
2020-10-22  9:44             ` Ferruh Yigit
2020-10-22  9:57               ` 谢华伟(此时此刻)
2020-10-22 15:51 ` [dpdk-dev] [PATCH v5 0/3] support both PIO and MMIO BAR for virtio PMD 谢华伟(此时此刻)
2020-10-22 15:51   ` [dpdk-dev] [PATCH v5 1/3] PCI: use PCI standard sysfs entry to get PIO address 谢华伟(此时此刻)
2021-01-12  8:07     ` Maxime Coquelin
2021-01-14 18:23       ` 谢华伟(此时此刻)
2021-01-24 15:10         ` Xueming(Steven) Li
2020-10-22 15:51   ` [dpdk-dev] [PATCH v5 2/3] PCI: support MMIO in rte_pci_ioport_map/unap/read/write 谢华伟(此时此刻)
2021-01-12  8:23     ` Maxime Coquelin
2021-01-21  6:30       ` 谢华伟(此时此刻)
2021-01-24 15:22     ` Xueming(Steven) Li
2021-01-25  3:08       ` 谢华伟(此时此刻)
2021-01-27 10:40     ` Ferruh Yigit
2021-01-27 15:34       ` 谢华伟(此时此刻)
2021-01-27 16:45         ` Ferruh Yigit
2020-10-22 15:51   ` [dpdk-dev] [PATCH v5 3/3] PCI: don't use vfio ioctl call to access PIO resource 谢华伟(此时此刻)
2021-01-12  9:37     ` Maxime Coquelin
2021-01-12 16:58       ` Maxime Coquelin
2021-01-20 14:54         ` 谢华伟(此时此刻)
2021-01-21  8:29           ` Maxime Coquelin
2021-01-21 14:57             ` 谢华伟(此时此刻)
2021-01-21 15:00               ` 谢华伟(此时此刻)
2021-01-21 15:38               ` Maxime Coquelin
2021-01-22  7:25                 ` 谢华伟(此时此刻)
2021-01-26 10:44                   ` Maxime Coquelin
2021-01-27 10:32                     ` Ferruh Yigit
2021-01-27 12:17                       ` Maxime Coquelin
2021-01-27 14:43                       ` 谢华伟(此时此刻)
2021-01-27 16:45                         ` Ferruh Yigit
2021-01-28 13:43                           ` 谢华伟(此时此刻)
2021-01-26 12:30                   ` 谢华伟(此时此刻)
2021-01-26 12:35                     ` Maxime Coquelin
2021-01-26 14:24                       ` 谢华伟(此时此刻)
2020-10-27  8:50   ` [dpdk-dev] [PATCH v5 0/3] support both PIO and MMIO BAR for virtio PMD 谢华伟(此时此刻)
2020-10-28  3:48     ` 谢华伟(此时此刻)
2020-11-02 11:56   ` 谢华伟(此时此刻)
2020-11-10 12:35   ` 谢华伟(此时此刻)
2020-11-10 12:42     ` David Marchand
2020-11-12 13:35       ` 谢华伟(此时此刻)
2020-12-14 14:24       ` 谢华伟(此时此刻)
2020-12-16  7:54         ` Maxime Coquelin
2021-01-12 17:37   ` Maxime Coquelin
2021-01-14 18:19     ` 谢华伟(此时此刻) [this message]
2021-01-21  4:12     ` 谢华伟(此时此刻)
2021-01-21  8:47       ` Maxime Coquelin
2021-01-21 13:51         ` 谢华伟(此时此刻)

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