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From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>,
	谢华伟(此时此刻) <huawei.xhw@alibaba-inc.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 3/3] PCI: don't use vfio ioctl call to access PIO resource
Date: Wed, 27 Jan 2021 10:32:27 +0000
Message-ID: <22010641-89a9-15f5-6079-591cfef7dabb@intel.com> (raw)
In-Reply-To: <71352868-a699-d876-25c3-b36df4f8649f@redhat.com>

On 1/26/2021 10:44 AM, Maxime Coquelin wrote:
> 
> 
> On 1/22/21 8:25 AM, 谢华伟(此时此刻) wrote:
>>
>> On 2021/1/21 23:38, Maxime Coquelin wrote:
>>>> Do you mean we apply or abandon patch 3? I am both OK. The first
>>>> priority to me is to enable MMIO bar support.
>>> OK, so yes, I think we should abandon patch 2 and patch 3.
>>> For patch 1, it looks valid to me, but I'll let Ferruh decide.
>>>
>>> For your device, if my understanding is correct, what we need to do is
>>> to support MMIO for legacy devices. Correct?
>> yes.
>>> If so, the change should be in virtio_pci.c. In vtpci_init(), after
>>> modern detection has failed, we should check the the BAR is PIO or MMIO
>>> based on the flag. the result can be saved in struct virtio_pci_dev.
>>>
>>>
>>> We would introduce new wrappers like vtpci_legacy_read,
>>> vtpci_legacy_write that would either call rte_pci_ioport_read,
>>> rte_pci_ioport_read in case of PIO, or rte_read32, rte_write32 in case
>>> of MMIO.
>>
>> There are two choices.
>>
>> 1, apply patch 2.
>>
>>      IO/MMIO port are mapped and accessed using the same API. Kernel is
>> doing in the same way like the following.
>>
>>              io_addr = pci_iomap
>>
>>                  get PIO directly or ioremap
>>
>>              iowrite16/32(val, io_addr + offset)
>>
>> I think applying patch 2 is a correct choice. It is a fix. Driver had
>> better not know if bar is PIO or MMIO.  ioport in ioport_xx API means
>> IO, not PIO.
>>
>> Btw, it only affects virtio PMD,  not that intrusive.
>>
>>   2, virtio specific change to enable MMIO support.
>>
>> Comparing with choice 1, i feels it is not that clean and pretty.
> 
> OK, that makes sense. I am OK with keeping patch 2, but would like
> Ferruh's ACK.
> 

I was waiting for clarification if this can be solved in virtio, which seems 
clarified and decided to go with this patch, I am OK to proceed with patch 1 & 2.

But first patch changes how PIO address get, it changes the Linux interface used 
to get the PIO.
And as far as I can see second patch requires this new interface to be able to 
access the MEM resources.

I have a concern that this interface change may cause issues with various 
distros, kernel versions etc.. And prefer it goes through a full -rc1 validation 
cycle.

Huawei, I am aware the patch is around for a while but to play safe, I suggest 
considering it for early next release, so it can be tested enough, instead of 
getting if for -rc2/3 in this release.

Thanks,
ferruh


> Could you please post v6?
> 
> Thanks,
> Maxime
> 
>>>
>>> It is not too late for this release, as the change will not be that
>>> intrusive. But if you prepare such patch, please base it on top of my
>>> virtio rework series; To make it easier to you, I added it to the dpdk-
>>> next-virtio tree:
>>> https://git.dpdk.org/next/dpdk-next-virtio/log/?h=virtio_pmd_rework_v2
>>>
>>> Thanks,
>>> Maxime
>>>
>>
> 


  reply	other threads:[~2021-01-27 10:32 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 [this message]
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)
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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