From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: "Ferruh Yigit" <ferruh.yigit@intel.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 13:17:13 +0100 [thread overview]
Message-ID: <08dc4816-4774-0ca0-f529-8ee68b221b93@redhat.com> (raw)
In-Reply-To: <22010641-89a9-15f5-6079-591cfef7dabb@intel.com>
On 1/27/21 11:32 AM, Ferruh Yigit wrote:
> 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.
While I think the risk for patch 2 is close to zero, I understand your
concern on patch 1 (especially with the upcoming holidays in China,
which will have an impact on QE capacity).
Huawei, do you think patch 2 can be slightly modified to be applied
alone, without patch 1? If possible, we may be able to pick patch2 for
this release and postpone patch 1 to v21.05?
> 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
>>>>
>>>
>>
>
next prev parent reply other threads:[~2021-01-27 12:17 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 [this message]
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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