From: Tom Rix <trix@redhat.com>
To: "Zhang, Tianfei" <tianfei.zhang@intel.com>,
"Wu, Hao" <hao.wu@intel.com>, "mdf@kernel.org" <mdf@kernel.org>,
"Xu, Yilun" <yilun.xu@intel.com>,
"linux-fpga@vger.kernel.org" <linux-fpga@vger.kernel.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "corbet@lwn.net" <corbet@lwn.net>,
Matthew Gerlach <matthew.gerlach@linux.intel.com>
Subject: Re: [PATCH v1 4/7] fpga: dfl: fix VF creation when ports have no local BAR space
Date: Fri, 18 Feb 2022 06:55:58 -0800 [thread overview]
Message-ID: <1281cbc7-7a1f-da84-3713-0d81982379ab@redhat.com> (raw)
In-Reply-To: <BN9PR11MB54830E0D185101B6B1517113E3379@BN9PR11MB5483.namprd11.prod.outlook.com>
On 2/18/22 12:14 AM, Zhang, Tianfei wrote:
>
>> -----Original Message-----
>> From: Tom Rix <trix@redhat.com>
>> Sent: Tuesday, February 15, 2022 11:51 PM
>> To: Zhang, Tianfei <tianfei.zhang@intel.com>; Wu, Hao <hao.wu@intel.com>;
>> mdf@kernel.org; Xu, Yilun <yilun.xu@intel.com>; linux-fpga@vger.kernel.org;
>> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org
>> Cc: corbet@lwn.net; Matthew Gerlach <matthew.gerlach@linux.intel.com>
>> Subject: Re: [PATCH v1 4/7] fpga: dfl: fix VF creation when ports have no local
>> BAR space
>>
>>
>> On 2/14/22 3:26 AM, Tianfei zhang wrote:
>>> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>>>
>>> When a port is not connected to the same PCIe endpoint as the FME, the
>>> port does not need to be released before being virtualized. Fix VF
>>> creation code to handle this new use
>> Similar, how does this fit in with iofs, this looks like it would not be valid for the
>> existing cards
> IOFS introducing multiple methods for PR and AFU access.
> 1. Legacy Model.
> 2. Micro-Personas in AFU.
> 3. Multiple VFs per PR slot.
>
> For 1 and 2 model, there are 1:1 mapping between Port device and PR slot (or entire AFU). In virtualization,
> it should release the Port device firstly and then assign to VM. In this models, the DFL driver will track that
> the number of port devices has released (cdev->released_port_num in dfl_fpga_cdev_config_ports_vf() function)
> are equal with the numbers of SRIOV or not. But in model 3, it has multiple VFs per PR slot, and assign the VF to VM
> without release the port device, so the tracking mechanism of cdev->released_port_num is not workable on new
If ->release_port_num is not workable, then it needs to be generalized.
Refactor to handle all the cases.
Tom
> model. This patch want to handle this new model during VF creation.
>
>>> case.
>>>
>>> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>>> Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
>>> ---
>>> drivers/fpga/dfl.c | 11 +++++++++--
>>> 1 file changed, 9 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index
>>> 26f8cf890700..cfc539a656f0 100644
>>> --- a/drivers/fpga/dfl.c
>>> +++ b/drivers/fpga/dfl.c
>>> @@ -1705,15 +1705,22 @@
>> EXPORT_SYMBOL_GPL(dfl_fpga_cdev_config_ports_pf);
>>> int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vfs)
>>> {
>>> struct dfl_feature_platform_data *pdata;
>>> - int ret = 0;
>>> + int ret = 0, port_count = 0;
>>>
>>> mutex_lock(&cdev->lock);
>>> +
>>> + list_for_each_entry(pdata, &cdev->port_dev_list, node) {
>>> + if (pdata->dev)
>> This looks wrong,
>>
>> pdata->dev is dereferenced below, if there is a case were (!pdata->dev)
>> here there would be crash later.
>>
>>> + continue;
>>> + port_count++;
>> how does this work when only some of the ports are handled in the new way ?
> This code want to handle the " Multiple VFs per PR slot" model as I mentioned above.
> In new model, the port_count want to count that how many port devices have released.
> This code looks not good readability, I try to re-write it.
>
>> Tom
>>
>>> + }
>>> +
>>> /*
>>> * can't turn multiple ports into 1 VF device, only 1 port for 1 VF
>>> * device, so if released port number doesn't match VF device number,
>>> * then reject the request with -EINVAL error code.
>>> */
>>> - if (cdev->released_port_num != num_vfs) {
>>> + if (port_count && cdev->released_port_num != num_vfs) {
>>> ret = -EINVAL;
>>> goto done;
>>> }
next prev parent reply other threads:[~2022-02-18 14:56 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-14 11:26 [PATCH v1 0/7] Add Intel OFS support for DFL driver Tianfei zhang
2022-02-14 11:26 ` [PATCH v1 1/7] Documentation: fpga: dfl: add description of IOFS Tianfei zhang
2022-02-14 12:18 ` Akira Yokosawa
2022-02-14 17:56 ` Randy Dunlap
2022-02-14 23:27 ` Zhang, Tianfei
2022-02-15 14:32 ` Tom Rix
2022-02-16 3:34 ` Wu, Hao
2022-02-21 7:39 ` Zhang, Tianfei
2022-02-14 11:26 ` [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info Tianfei zhang
2022-02-15 14:49 ` Tom Rix
2022-02-17 2:38 ` Xu Yilun
2022-02-21 7:54 ` Zhang, Tianfei
2022-02-18 6:53 ` Zhang, Tianfei
2022-02-18 14:29 ` Tom Rix
2022-02-21 12:05 ` Zhang, Tianfei
2022-02-16 3:35 ` Wu, Hao
2022-02-21 7:41 ` Zhang, Tianfei
2022-02-14 11:26 ` [PATCH v1 3/7] fpga: dfl: Allow for ports with no local bar space Tianfei zhang
2022-02-15 15:05 ` Tom Rix
2022-02-18 7:31 ` Zhang, Tianfei
2022-02-18 14:49 ` Tom Rix
2022-02-21 17:22 ` matthew.gerlach
2022-02-21 17:51 ` Tom Rix
2022-02-22 9:07 ` Zhang, Tianfei
2022-02-16 3:38 ` Wu, Hao
2022-02-21 7:48 ` Zhang, Tianfei
2022-02-14 11:26 ` [PATCH v1 4/7] fpga: dfl: fix VF creation when ports have no local BAR space Tianfei zhang
2022-02-15 15:50 ` Tom Rix
2022-02-18 8:14 ` Zhang, Tianfei
2022-02-18 14:55 ` Tom Rix [this message]
2022-02-14 11:26 ` [PATCH v1 5/7] drivers: fpga: dfl: handle empty port list Tianfei zhang
2022-02-15 15:55 ` Tom Rix
2022-02-18 8:24 ` Zhang, Tianfei
2022-02-14 11:26 ` [PATCH v1 6/7] fpga: dfl: Handle dfl's starting with AFU Tianfei zhang
2022-02-15 16:09 ` Tom Rix
2022-02-14 11:26 ` [PATCH v1 7/7] fpga: dfl: pci: Add generic OFS PCI PID Tianfei zhang
2022-02-15 16:16 ` Tom Rix
2022-02-18 9:03 ` Zhang, Tianfei
2022-02-18 15:27 ` Tom Rix
2022-02-21 17:50 ` matthew.gerlach
2022-02-21 18:09 ` Tom Rix
2022-02-22 3:11 ` Zhang, Tianfei
2022-02-22 16:11 ` Tom Rix
2022-02-23 1:48 ` Zhang, Tianfei
2022-02-24 17:54 ` matthew.gerlach
2022-02-28 10:57 ` Wu, Hao
2022-03-01 0:25 ` matthew.gerlach
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