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Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put

Started byAlex Williamson <alex.williamson@redhat.com>
First post2016-05-19 23:10 +0200
Last post2016-05-20 18:30 +0200
Articles 7 — 4 participants

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  Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Alex Williamson <alex.williamson@redhat.com> - 2016-05-19 23:10 +0200
    Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Eric Auger <eric.auger@linaro.org> - 2016-05-20 10:10 +0200
      Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Baptiste Reynal <b.reynal@virtualopensystems.com> - 2016-05-20 10:30 +0200
        Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Peng Fan <van.freenix@gmail.com> - 2016-05-20 10:40 +0200
          Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Eric Auger <eric.auger@linaro.org> - 2016-05-20 11:30 +0200
            Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Peng Fan <van.freenix@gmail.com> - 2016-05-20 12:00 +0200
              Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Eric Auger <eric.auger@linaro.org> - 2016-05-20 18:30 +0200

#1403965 — Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put

FromAlex Williamson <alex.williamson@redhat.com>
Date2016-05-19 23:10 +0200
SubjectRe: [PATCH] vfio: platform: use vfio_iommu_group_get/put
Message-ID<rADmG-524-5@gated-at.bofh.it>
On Tue, 10 May 2016 15:40:28 +0800
Peng Fan <van.freenix@gmail.com> wrote:

> Hi Alex,
> 
> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
> >On Mon,  9 May 2016 18:01:43 +0800
> >Peng Fan <van.freenix@gmail.com> wrote:
> >  
> >> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
> >> iommu_group_get or iommu_group_put.  
> >
> >I assume you're trying to duplicate the vfio_pci changes from commit
> >03a76b60f8ba to enable no-iommu mode.  That would be really relevant
> >information for the commit log.  
> 
> This is not to support non-iommu for vfio platform. I just think
> vfio_iommu_group_get/put is vfio core API and should be used by
> vfio-pci and vfio-platform.

Hi Peng,

I suppose I would consider this an optional part of the internal vfio
API, it's only real purpose it to provide the ability to create fake
groups which are only used for no-iommu.  It's perfectly legitimate to
use iommu_group_get/put if there is no desire to enable no-iommu.
Baptiste, Eric, do you have an opinion whether enabling no-iommu in
vfio/platform is something we should do?  Thanks,

Alex

> >> 
> >> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> >> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
> >> Cc: Alex Williamson <alex.williamson@redhat.com>
> >> ---
> >>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >> 
> >> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> >> index e65b142..582885e 100644
> >> --- a/drivers/vfio/platform/vfio_platform_common.c
> >> +++ b/drivers/vfio/platform/vfio_platform_common.c
> >> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> >>  
> >>  	vdev->device = dev;
> >>  
> >> -	group = iommu_group_get(dev);
> >> +	group = vfio_iommu_group_get(dev);
> >>  	if (!group) {
> >>  		pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
> >>  		return -EINVAL;
> >> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> >>  
> >>  	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
> >>  	if (ret) {
> >> -		iommu_group_put(group);
> >> +		vfio_iommu_group_put(group);
> >>  		return ret;
> >>  	}
> >>  
> >> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
> >>  
> >>  	if (vdev) {
> >>  		vfio_platform_put_reset(vdev);
> >> -		iommu_group_put(dev->iommu_group);
> >> +		vfio_iommu_group_put(dev->iommu_group, dev);
> >>  	}
> >>  
> >>  	return vdev;  
> >

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#1404215

FromEric Auger <eric.auger@linaro.org>
Date2016-05-20 10:10 +0200
Message-ID<rANFn-32l-7@gated-at.bofh.it>
In reply to#1403965
Hi,
On 05/19/2016 11:01 PM, Alex Williamson wrote:
> On Tue, 10 May 2016 15:40:28 +0800
> Peng Fan <van.freenix@gmail.com> wrote:
> 
>> Hi Alex,
>>
>> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
>>> On Mon,  9 May 2016 18:01:43 +0800
>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>  
>>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
>>>> iommu_group_get or iommu_group_put.  
>>>
>>> I assume you're trying to duplicate the vfio_pci changes from commit
>>> 03a76b60f8ba to enable no-iommu mode.  That would be really relevant
>>> information for the commit log.  
>>
>> This is not to support non-iommu for vfio platform. I just think
>> vfio_iommu_group_get/put is vfio core API and should be used by
>> vfio-pci and vfio-platform.
> 
> Hi Peng,
> 
> I suppose I would consider this an optional part of the internal vfio
> API, it's only real purpose it to provide the ability to create fake
> groups which are only used for no-iommu.  It's perfectly legitimate to
> use iommu_group_get/put if there is no desire to enable no-iommu.
> Baptiste, Eric, do you have an opinion whether enabling no-iommu in
> vfio/platform is something we should do?  Thanks,
I think it would make sense to introduce that no-iommu feature for
vfio-platform because it allows potential users to get familiar with
VFIO platform without having the proper HW. I also thought the primary
purpose of this patch was to introduce that support.

Best Regards

Eric
> 
> Alex
> 
>>>>
>>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>>> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
>>>> Cc: Alex Williamson <alex.williamson@redhat.com>
>>>> ---
>>>>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>>>> index e65b142..582885e 100644
>>>> --- a/drivers/vfio/platform/vfio_platform_common.c
>>>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>  
>>>>  	vdev->device = dev;
>>>>  
>>>> -	group = iommu_group_get(dev);
>>>> +	group = vfio_iommu_group_get(dev);
>>>>  	if (!group) {
>>>>  		pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
>>>>  		return -EINVAL;
>>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>  
>>>>  	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
>>>>  	if (ret) {
>>>> -		iommu_group_put(group);
>>>> +		vfio_iommu_group_put(group);
>>>>  		return ret;
>>>>  	}
>>>>  
>>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
>>>>  
>>>>  	if (vdev) {
>>>>  		vfio_platform_put_reset(vdev);
>>>> -		iommu_group_put(dev->iommu_group);
>>>> +		vfio_iommu_group_put(dev->iommu_group, dev);
>>>>  	}
>>>>  
>>>>  	return vdev;  
>>>  
>

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#1404241

FromBaptiste Reynal <b.reynal@virtualopensystems.com>
Date2016-05-20 10:30 +0200
Message-ID<rANYK-38Z-35@gated-at.bofh.it>
In reply to#1404215
Hi,

On Fri, May 20, 2016 at 9:58 AM, Eric Auger <eric.auger@linaro.org> wrote:
>
> Hi,
> On 05/19/2016 11:01 PM, Alex Williamson wrote:
> > On Tue, 10 May 2016 15:40:28 +0800
> > Peng Fan <van.freenix@gmail.com> wrote:
> >
> >> Hi Alex,
> >>
> >> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
> >>> On Mon,  9 May 2016 18:01:43 +0800
> >>> Peng Fan <van.freenix@gmail.com> wrote:
> >>>
> >>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
> >>>> iommu_group_get or iommu_group_put.
> >>>
> >>> I assume you're trying to duplicate the vfio_pci changes from commit
> >>> 03a76b60f8ba to enable no-iommu mode.  That would be really relevant
> >>> information for the commit log.
> >>
> >> This is not to support non-iommu for vfio platform. I just think
> >> vfio_iommu_group_get/put is vfio core API and should be used by
> >> vfio-pci and vfio-platform.
> >
> > Hi Peng,
> >
> > I suppose I would consider this an optional part of the internal vfio
> > API, it's only real purpose it to provide the ability to create fake
> > groups which are only used for no-iommu.  It's perfectly legitimate to
> > use iommu_group_get/put if there is no desire to enable no-iommu.
> > Baptiste, Eric, do you have an opinion whether enabling no-iommu in
> > vfio/platform is something we should do?  Thanks,
> I think it would make sense to introduce that no-iommu feature for
> vfio-platform because it allows potential users to get familiar with
> VFIO platform without having the proper HW. I also thought the primary
> purpose of this patch was to introduce that support.

Since safety issues have already been addressed for the PCI patch
series, I don't see any reason not to enable it. You might extend the
commit message to remind those issues.

Best regards,
Baptiste

>
> Best Regards
>
> Eric
> >
> > Alex
> >
> >>>>
> >>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> >>>> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
> >>>> Cc: Alex Williamson <alex.williamson@redhat.com>
> >>>> ---
> >>>>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
> >>>>  1 file changed, 3 insertions(+), 3 deletions(-)
> >>>>
> >>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> >>>> index e65b142..582885e 100644
> >>>> --- a/drivers/vfio/platform/vfio_platform_common.c
> >>>> +++ b/drivers/vfio/platform/vfio_platform_common.c
> >>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> >>>>
> >>>>    vdev->device = dev;
> >>>>
> >>>> -  group = iommu_group_get(dev);
> >>>> +  group = vfio_iommu_group_get(dev);
> >>>>    if (!group) {
> >>>>            pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
> >>>>            return -EINVAL;
> >>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> >>>>
> >>>>    ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
> >>>>    if (ret) {
> >>>> -          iommu_group_put(group);
> >>>> +          vfio_iommu_group_put(group);
> >>>>            return ret;
> >>>>    }
> >>>>
> >>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
> >>>>
> >>>>    if (vdev) {
> >>>>            vfio_platform_put_reset(vdev);
> >>>> -          iommu_group_put(dev->iommu_group);
> >>>> +          vfio_iommu_group_put(dev->iommu_group, dev);
> >>>>    }
> >>>>
> >>>>    return vdev;
> >>>
> >
>

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#1404245

FromPeng Fan <van.freenix@gmail.com>
Date2016-05-20 10:40 +0200
Message-ID<rAO8p-3ca-9@gated-at.bofh.it>
In reply to#1404241
Hi,

On Fri, May 20, 2016 at 10:20:32AM +0200, Baptiste Reynal wrote:
>Hi,
>
>On Fri, May 20, 2016 at 9:58 AM, Eric Auger <eric.auger@linaro.org> wrote:
>>
>> Hi,
>> On 05/19/2016 11:01 PM, Alex Williamson wrote:
>> > On Tue, 10 May 2016 15:40:28 +0800
>> > Peng Fan <van.freenix@gmail.com> wrote:
>> >
>> >> Hi Alex,
>> >>
>> >> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
>> >>> On Mon,  9 May 2016 18:01:43 +0800
>> >>> Peng Fan <van.freenix@gmail.com> wrote:
>> >>>
>> >>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
>> >>>> iommu_group_get or iommu_group_put.
>> >>>
>> >>> I assume you're trying to duplicate the vfio_pci changes from commit
>> >>> 03a76b60f8ba to enable no-iommu mode.  That would be really relevant
>> >>> information for the commit log.
>> >>
>> >> This is not to support non-iommu for vfio platform. I just think
>> >> vfio_iommu_group_get/put is vfio core API and should be used by
>> >> vfio-pci and vfio-platform.
>> >
>> > Hi Peng,
>> >
>> > I suppose I would consider this an optional part of the internal vfio
>> > API, it's only real purpose it to provide the ability to create fake
>> > groups which are only used for no-iommu.  It's perfectly legitimate to
>> > use iommu_group_get/put if there is no desire to enable no-iommu.
>> > Baptiste, Eric, do you have an opinion whether enabling no-iommu in
>> > vfio/platform is something we should do?  Thanks,
>> I think it would make sense to introduce that no-iommu feature for
>> vfio-platform because it allows potential users to get familiar with
>> VFIO platform without having the proper HW. I also thought the primary
>> purpose of this patch was to introduce that support.

Yeah. Initially I would like to try vfio on my i.MX6/7 boards which does not
have HW iommu. I am new to this, so just wrote this simple patch when I was
reading the source code.

>
>Since safety issues have already been addressed for the PCI patch
>series, I don't see any reason not to enable it. You might extend the
>commit message to remind those issues.

Eric, Baptiste,

Is vfio-platform no-iommu on your TODO list? I am happy to help test.
If not, I can try work on this if you could guide me -:)

Thanks,
Peng.
>
>Best regards,
>Baptiste
>
>>
>> Best Regards
>>
>> Eric
>> >
>> > Alex
>> >
>> >>>>
>> >>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>> >>>> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
>> >>>> Cc: Alex Williamson <alex.williamson@redhat.com>
>> >>>> ---
>> >>>>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
>> >>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>> >>>>
>> >>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>> >>>> index e65b142..582885e 100644
>> >>>> --- a/drivers/vfio/platform/vfio_platform_common.c
>> >>>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>> >>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>> >>>>
>> >>>>    vdev->device = dev;
>> >>>>
>> >>>> -  group = iommu_group_get(dev);
>> >>>> +  group = vfio_iommu_group_get(dev);
>> >>>>    if (!group) {
>> >>>>            pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
>> >>>>            return -EINVAL;
>> >>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>> >>>>
>> >>>>    ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
>> >>>>    if (ret) {
>> >>>> -          iommu_group_put(group);
>> >>>> +          vfio_iommu_group_put(group);
>> >>>>            return ret;
>> >>>>    }
>> >>>>
>> >>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
>> >>>>
>> >>>>    if (vdev) {
>> >>>>            vfio_platform_put_reset(vdev);
>> >>>> -          iommu_group_put(dev->iommu_group);
>> >>>> +          vfio_iommu_group_put(dev->iommu_group, dev);
>> >>>>    }
>> >>>>
>> >>>>    return vdev;
>> >>>
>> >
>>

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#1404278

FromEric Auger <eric.auger@linaro.org>
Date2016-05-20 11:30 +0200
Message-ID<rAOUO-3HG-13@gated-at.bofh.it>
In reply to#1404245
Hi Peng,
On 05/20/2016 10:36 AM, Peng Fan wrote:
> Hi,
> 
> On Fri, May 20, 2016 at 10:20:32AM +0200, Baptiste Reynal wrote:
>> Hi,
>>
>> On Fri, May 20, 2016 at 9:58 AM, Eric Auger <eric.auger@linaro.org> wrote:
>>>
>>> Hi,
>>> On 05/19/2016 11:01 PM, Alex Williamson wrote:
>>>> On Tue, 10 May 2016 15:40:28 +0800
>>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>>
>>>>> Hi Alex,
>>>>>
>>>>> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
>>>>>> On Mon,  9 May 2016 18:01:43 +0800
>>>>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>>>>
>>>>>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
>>>>>>> iommu_group_get or iommu_group_put.
>>>>>>
>>>>>> I assume you're trying to duplicate the vfio_pci changes from commit
>>>>>> 03a76b60f8ba to enable no-iommu mode.  That would be really relevant
>>>>>> information for the commit log.
>>>>>
>>>>> This is not to support non-iommu for vfio platform. I just think
>>>>> vfio_iommu_group_get/put is vfio core API and should be used by
>>>>> vfio-pci and vfio-platform.
>>>>
>>>> Hi Peng,
>>>>
>>>> I suppose I would consider this an optional part of the internal vfio
>>>> API, it's only real purpose it to provide the ability to create fake
>>>> groups which are only used for no-iommu.  It's perfectly legitimate to
>>>> use iommu_group_get/put if there is no desire to enable no-iommu.
>>>> Baptiste, Eric, do you have an opinion whether enabling no-iommu in
>>>> vfio/platform is something we should do?  Thanks,
>>> I think it would make sense to introduce that no-iommu feature for
>>> vfio-platform because it allows potential users to get familiar with
>>> VFIO platform without having the proper HW. I also thought the primary
>>> purpose of this patch was to introduce that support.
> 
> Yeah. Initially I would like to try vfio on my i.MX6/7 boards which does not
> have HW iommu. I am new to this, so just wrote this simple patch when I was
> reading the source code.
> 
>>
>> Since safety issues have already been addressed for the PCI patch
>> series, I don't see any reason not to enable it. You might extend the
>> commit message to remind those issues.
> 
> Eric, Baptiste,
> 
> Is vfio-platform no-iommu on your TODO list? I am happy to help test.
> If not, I can try work on this if you could guide me -:)
No it is not at the moment. shouldn't it work already with this very
patch? I will be happy to bring support to you if needed.

Best Regards

Eric
> 
> Thanks,
> Peng.
>>
>> Best regards,
>> Baptiste
>>
>>>
>>> Best Regards
>>>
>>> Eric
>>>>
>>>> Alex
>>>>
>>>>>>>
>>>>>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>>>>>> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
>>>>>>> Cc: Alex Williamson <alex.williamson@redhat.com>
>>>>>>> ---
>>>>>>>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
>>>>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>>>>>>> index e65b142..582885e 100644
>>>>>>> --- a/drivers/vfio/platform/vfio_platform_common.c
>>>>>>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>>>>>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>>>>
>>>>>>>    vdev->device = dev;
>>>>>>>
>>>>>>> -  group = iommu_group_get(dev);
>>>>>>> +  group = vfio_iommu_group_get(dev);
>>>>>>>    if (!group) {
>>>>>>>            pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
>>>>>>>            return -EINVAL;
>>>>>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>>>>
>>>>>>>    ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
>>>>>>>    if (ret) {
>>>>>>> -          iommu_group_put(group);
>>>>>>> +          vfio_iommu_group_put(group);
>>>>>>>            return ret;
>>>>>>>    }
>>>>>>>
>>>>>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
>>>>>>>
>>>>>>>    if (vdev) {
>>>>>>>            vfio_platform_put_reset(vdev);
>>>>>>> -          iommu_group_put(dev->iommu_group);
>>>>>>> +          vfio_iommu_group_put(dev->iommu_group, dev);
>>>>>>>    }
>>>>>>>
>>>>>>>    return vdev;
>>>>>>
>>>>
>>>

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#1404291

FromPeng Fan <van.freenix@gmail.com>
Date2016-05-20 12:00 +0200
Message-ID<rAPnP-3SW-7@gated-at.bofh.it>
In reply to#1404278
Hi Eric,

On Fri, May 20, 2016 at 11:22:13AM +0200, Eric Auger wrote:
>Hi Peng,
>On 05/20/2016 10:36 AM, Peng Fan wrote:
>> Hi,
>> 
>> On Fri, May 20, 2016 at 10:20:32AM +0200, Baptiste Reynal wrote:
>>> Hi,
>>>
>>> On Fri, May 20, 2016 at 9:58 AM, Eric Auger <eric.auger@linaro.org> wrote:
>>>>
>>>> Hi,
>>>> On 05/19/2016 11:01 PM, Alex Williamson wrote:
>>>>> On Tue, 10 May 2016 15:40:28 +0800
>>>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>>>
>>>>>> Hi Alex,
>>>>>>
>>>>>> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
>>>>>>> On Mon,  9 May 2016 18:01:43 +0800
>>>>>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>>>>>
>>>>>>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
>>>>>>>> iommu_group_get or iommu_group_put.
>>>>>>>
>>>>>>> I assume you're trying to duplicate the vfio_pci changes from commit
>>>>>>> 03a76b60f8ba to enable no-iommu mode.  That would be really relevant
>>>>>>> information for the commit log.
>>>>>>
>>>>>> This is not to support non-iommu for vfio platform. I just think
>>>>>> vfio_iommu_group_get/put is vfio core API and should be used by
>>>>>> vfio-pci and vfio-platform.
>>>>>
>>>>> Hi Peng,
>>>>>
>>>>> I suppose I would consider this an optional part of the internal vfio
>>>>> API, it's only real purpose it to provide the ability to create fake
>>>>> groups which are only used for no-iommu.  It's perfectly legitimate to
>>>>> use iommu_group_get/put if there is no desire to enable no-iommu.
>>>>> Baptiste, Eric, do you have an opinion whether enabling no-iommu in
>>>>> vfio/platform is something we should do?  Thanks,
>>>> I think it would make sense to introduce that no-iommu feature for
>>>> vfio-platform because it allows potential users to get familiar with
>>>> VFIO platform without having the proper HW. I also thought the primary
>>>> purpose of this patch was to introduce that support.
>> 
>> Yeah. Initially I would like to try vfio on my i.MX6/7 boards which does not
>> have HW iommu. I am new to this, so just wrote this simple patch when I was
>> reading the source code.
>> 
>>>
>>> Since safety issues have already been addressed for the PCI patch
>>> series, I don't see any reason not to enable it. You might extend the
>>> commit message to remind those issues.
>> 
>> Eric, Baptiste,
>> 
>> Is vfio-platform no-iommu on your TODO list? I am happy to help test.
>> If not, I can try work on this if you could guide me -:)
>No it is not at the moment. shouldn't it work already with this very
>patch? I will be happy to bring support to you if needed.

This patch was code inspection work. Since it did not break vfio-platform
iommu, I sent it out. I have not played well with userspace test
code/step or qemu (:

Is it ok for me to test vfio-platform no-iommu using a platform device
withou DMA capability, such as simple UART?

If it's ok, I'll follow the test code[1] to write my test code and do some test.

Regards,
Peng.

[1] https://github.com/virtualopensystems/vfio-host-test/tree/master/src_test

>
>Best Regards
>
>Eric
>> 
>> Thanks,
>> Peng.
>>>
>>> Best regards,
>>> Baptiste
>>>
>>>>
>>>> Best Regards
>>>>
>>>> Eric
>>>>>
>>>>> Alex
>>>>>
>>>>>>>>
>>>>>>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>>>>>>> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
>>>>>>>> Cc: Alex Williamson <alex.williamson@redhat.com>
>>>>>>>> ---
>>>>>>>>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
>>>>>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>>>>>>>> index e65b142..582885e 100644
>>>>>>>> --- a/drivers/vfio/platform/vfio_platform_common.c
>>>>>>>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>>>>>>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>>>>>
>>>>>>>>    vdev->device = dev;
>>>>>>>>
>>>>>>>> -  group = iommu_group_get(dev);
>>>>>>>> +  group = vfio_iommu_group_get(dev);
>>>>>>>>    if (!group) {
>>>>>>>>            pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
>>>>>>>>            return -EINVAL;
>>>>>>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>>>>>
>>>>>>>>    ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
>>>>>>>>    if (ret) {
>>>>>>>> -          iommu_group_put(group);
>>>>>>>> +          vfio_iommu_group_put(group);
>>>>>>>>            return ret;
>>>>>>>>    }
>>>>>>>>
>>>>>>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
>>>>>>>>
>>>>>>>>    if (vdev) {
>>>>>>>>            vfio_platform_put_reset(vdev);
>>>>>>>> -          iommu_group_put(dev->iommu_group);
>>>>>>>> +          vfio_iommu_group_put(dev->iommu_group, dev);
>>>>>>>>    }
>>>>>>>>
>>>>>>>>    return vdev;
>>>>>>>
>>>>>
>>>>
>

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#1404579

FromEric Auger <eric.auger@linaro.org>
Date2016-05-20 18:30 +0200
Message-ID<rAVtf-7Ld-13@gated-at.bofh.it>
In reply to#1404291
Hi Peng,
On 05/20/2016 11:56 AM, Peng Fan wrote:
> Hi Eric,
> 
> On Fri, May 20, 2016 at 11:22:13AM +0200, Eric Auger wrote:
>> Hi Peng,
>> On 05/20/2016 10:36 AM, Peng Fan wrote:
>>> Hi,
>>>
>>> On Fri, May 20, 2016 at 10:20:32AM +0200, Baptiste Reynal wrote:
>>>> Hi,
>>>>
>>>> On Fri, May 20, 2016 at 9:58 AM, Eric Auger <eric.auger@linaro.org> wrote:
>>>>>
>>>>> Hi,
>>>>> On 05/19/2016 11:01 PM, Alex Williamson wrote:
>>>>>> On Tue, 10 May 2016 15:40:28 +0800
>>>>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>>>>
>>>>>>> Hi Alex,
>>>>>>>
>>>>>>> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote:
>>>>>>>> On Mon,  9 May 2016 18:01:43 +0800
>>>>>>>> Peng Fan <van.freenix@gmail.com> wrote:
>>>>>>>>
>>>>>>>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not
>>>>>>>>> iommu_group_get or iommu_group_put.
>>>>>>>>
>>>>>>>> I assume you're trying to duplicate the vfio_pci changes from commit
>>>>>>>> 03a76b60f8ba to enable no-iommu mode.  That would be really relevant
>>>>>>>> information for the commit log.
>>>>>>>
>>>>>>> This is not to support non-iommu for vfio platform. I just think
>>>>>>> vfio_iommu_group_get/put is vfio core API and should be used by
>>>>>>> vfio-pci and vfio-platform.
>>>>>>
>>>>>> Hi Peng,
>>>>>>
>>>>>> I suppose I would consider this an optional part of the internal vfio
>>>>>> API, it's only real purpose it to provide the ability to create fake
>>>>>> groups which are only used for no-iommu.  It's perfectly legitimate to
>>>>>> use iommu_group_get/put if there is no desire to enable no-iommu.
>>>>>> Baptiste, Eric, do you have an opinion whether enabling no-iommu in
>>>>>> vfio/platform is something we should do?  Thanks,
>>>>> I think it would make sense to introduce that no-iommu feature for
>>>>> vfio-platform because it allows potential users to get familiar with
>>>>> VFIO platform without having the proper HW. I also thought the primary
>>>>> purpose of this patch was to introduce that support.
>>>
>>> Yeah. Initially I would like to try vfio on my i.MX6/7 boards which does not
>>> have HW iommu. I am new to this, so just wrote this simple patch when I was
>>> reading the source code.
>>>
>>>>
>>>> Since safety issues have already been addressed for the PCI patch
>>>> series, I don't see any reason not to enable it. You might extend the
>>>> commit message to remind those issues.
>>>
>>> Eric, Baptiste,
>>>
>>> Is vfio-platform no-iommu on your TODO list? I am happy to help test.
>>> If not, I can try work on this if you could guide me -:)
>> No it is not at the moment. shouldn't it work already with this very
>> patch? I will be happy to bring support to you if needed.
> 
> This patch was code inspection work. Since it did not break vfio-platform
> iommu, I sent it out. I have not played well with userspace test
> code/step or qemu (:
> 
> Is it ok for me to test vfio-platform no-iommu using a platform device
> withou DMA capability, such as simple UART?

My feeling is that it is a reasonable start.

Best Regards

Eric
> 
> If it's ok, I'll follow the test code[1] to write my test code and do some test.
> 
> Regards,
> Peng.
> 
> [1] https://github.com/virtualopensystems/vfio-host-test/tree/master/src_test
> 
>>
>> Best Regards
>>
>> Eric
>>>
>>> Thanks,
>>> Peng.
>>>>
>>>> Best regards,
>>>> Baptiste
>>>>
>>>>>
>>>>> Best Regards
>>>>>
>>>>> Eric
>>>>>>
>>>>>> Alex
>>>>>>
>>>>>>>>>
>>>>>>>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>>>>>>>> Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
>>>>>>>>> Cc: Alex Williamson <alex.williamson@redhat.com>
>>>>>>>>> ---
>>>>>>>>>  drivers/vfio/platform/vfio_platform_common.c | 6 +++---
>>>>>>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>>>>>>>>> index e65b142..582885e 100644
>>>>>>>>> --- a/drivers/vfio/platform/vfio_platform_common.c
>>>>>>>>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>>>>>>>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>>>>>>
>>>>>>>>>    vdev->device = dev;
>>>>>>>>>
>>>>>>>>> -  group = iommu_group_get(dev);
>>>>>>>>> +  group = vfio_iommu_group_get(dev);
>>>>>>>>>    if (!group) {
>>>>>>>>>            pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
>>>>>>>>>            return -EINVAL;
>>>>>>>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>>>>>>>>
>>>>>>>>>    ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
>>>>>>>>>    if (ret) {
>>>>>>>>> -          iommu_group_put(group);
>>>>>>>>> +          vfio_iommu_group_put(group);
>>>>>>>>>            return ret;
>>>>>>>>>    }
>>>>>>>>>
>>>>>>>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
>>>>>>>>>
>>>>>>>>>    if (vdev) {
>>>>>>>>>            vfio_platform_put_reset(vdev);
>>>>>>>>> -          iommu_group_put(dev->iommu_group);
>>>>>>>>> +          vfio_iommu_group_put(dev->iommu_group, dev);
>>>>>>>>>    }
>>>>>>>>>
>>>>>>>>>    return vdev;
>>>>>>>>
>>>>>>
>>>>>
>>

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