From: Pierre Morel <pmorel@linux.ibm.com>
To: Cornelia Huck <cohuck@redhat.com>
Cc: Halil Pasic <pasic@linux.ibm.com>,
linux-kernel@vger.kernel.org, borntraeger@de.ibm.com,
frankja@linux.ibm.com, mst@redhat.com, jasowang@redhat.com,
kvm@vger.kernel.org, linux-s390@vger.kernel.org,
virtualization@lists.linux-foundation.org,
thomas.lendacky@amd.com, david@gibson.dropbear.id.au,
linuxram@us.ibm.com, heiko.carstens@de.ibm.com,
gor@linux.ibm.com
Subject: Re: [PATCH v3 1/1] s390: virtio: let arch accept devices without IOMMU feature
Date: Mon, 29 Jun 2020 18:10:02 +0200 [thread overview]
Message-ID: <4777633f-728b-1a67-c870-0fafa313e468@linux.ibm.com> (raw)
In-Reply-To: <20200629154439.14cc5ae7.cohuck@redhat.com>
On 2020-06-29 15:44, Cornelia Huck wrote:
> On Mon, 29 Jun 2020 15:14:04 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
>
>> On 2020-06-19 11:20, Cornelia Huck wrote:
>>> On Thu, 18 Jun 2020 00:29:56 +0200
>>> Halil Pasic <pasic@linux.ibm.com> wrote:
>>>
>>>> On Wed, 17 Jun 2020 12:43:57 +0200
>>>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>
>>>>> @@ -179,6 +194,13 @@ int virtio_finalize_features(struct virtio_device *dev)
>>>>> if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
>>>>> return 0;
>>>>>
>>>>> + if (arch_needs_virtio_iommu_platform(dev) &&
>>>>> + !virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) {
>>>>> + dev_warn(&dev->dev,
>>>>> + "virtio: device must provide VIRTIO_F_IOMMU_PLATFORM\n");
>
> [Side note: wasn't there a patch renaming this bit on the list? I think
> this name is only kept for userspace compat.]
Sorry, I do not understand what you expect from me.
On which mailing list you think there is a patch on?
>
>>>>
>>>> I'm not sure, divulging the current Linux name of this feature bit is a
>>>> good idea, but if everybody else is fine with this, I don't care that
>>>
>>> Not sure if that feature name will ever change, as it is exported in
>>> headers. At most, we might want to add the new ACCESS_PLATFORM define
>>> and keep the old one, but that would still mean some churn.
>>>
>>>> much. An alternative would be:
>>>> "virtio: device falsely claims to have full access to the memory,
>>>> aborting the device"
>>>
>>> "virtio: device does not work with limited memory access" ?
>>>
>>> But no issue with keeping the current message.
>>>
>>
>> If it is OK, I would like to specify that the arch is responsible to
>> accept or not the device.
>> The reason why the device is not accepted without IOMMU_PLATFORM is arch
>> specific.
>
> Hm, I'd think the reason is always the same (the device cannot access
> the memory directly), just the way to figure out whether that is the
> case or not is arch-specific, as with so many other things. No real
> need to go into detail here, I think.
>
As you like, so I rename the subject to:
"virtio: device does not work with limited memory access"
Regards,
Pierre
--
Pierre Morel
IBM Lab Boeblingen
next prev parent reply other threads:[~2020-06-29 21:29 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 10:43 [PATCH v3 0/1] s390: virtio: let arch choose to accept devices without IOMMU feature Pierre Morel
2020-06-17 10:43 ` [PATCH v3 1/1] s390: virtio: let arch " Pierre Morel
2020-06-17 11:22 ` Heiko Carstens
2020-06-17 11:59 ` Pierre Morel
2020-06-17 13:36 ` Tom Lendacky
2020-06-17 14:12 ` Pierre Morel
2020-06-17 22:29 ` Halil Pasic
2020-06-19 9:20 ` Cornelia Huck
2020-06-19 12:02 ` Halil Pasic
2020-06-29 13:15 ` Pierre Morel
2020-06-29 13:14 ` Pierre Morel
2020-06-29 13:44 ` Cornelia Huck
2020-06-29 16:10 ` Pierre Morel [this message]
2020-06-29 13:21 ` Pierre Morel
2020-06-29 15:57 ` Michael S. Tsirkin
2020-06-29 16:05 ` Cornelia Huck
2020-07-02 13:03 ` Pierre Morel
2020-07-06 13:37 ` Pierre Morel
2020-07-06 14:33 ` Cornelia Huck
2020-07-06 15:01 ` Pierre Morel
2020-06-29 16:09 ` Pierre Morel
2020-06-29 16:09 ` Michael S. Tsirkin
2020-06-29 16:48 ` Pierre Morel
2020-06-29 21:18 ` Michael S. Tsirkin
2020-06-30 7:08 ` Cornelia Huck
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