From: Pierre Morel <pmorel@linux.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
linux-kernel@vger.kernel.org
Cc: pasic@linux.ibm.com, frankja@linux.ibm.com, mst@redhat.com,
jasowang@redhat.com, cohuck@redhat.com, kvm@vger.kernel.org,
linux-s390@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2 1/1] s390: virtio: let arch accept devices without IOMMU feature
Date: Tue, 16 Jun 2020 09:35:19 +0200 [thread overview]
Message-ID: <a93bf169-55ca-2a77-f9a5-b27bf18176e2@linux.ibm.com> (raw)
In-Reply-To: <74b6cf8a-d5a6-e0bf-f1c1-e453af133614@de.ibm.com>
On 2020-06-16 08:55, Christian Borntraeger wrote:
>
>
> On 15.06.20 14:39, Pierre Morel wrote:
>> An architecture protecting the guest memory against unauthorized host
>> access may want to enforce VIRTIO I/O device protection through the
>> use of VIRTIO_F_IOMMU_PLATFORM.
>>
>> Let's give a chance to the architecture to accept or not devices
>> without VIRTIO_F_IOMMU_PLATFORM.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>
>
> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Thanks,
>
> Shouldnt we maybe add a pr_warn if that happens to help the admins to understand what is going on?
>
>
Yes, Connie asked for it too, good that you remind it to me, I add it.
Thanks,
Pierre
>> ---
>> arch/s390/mm/init.c | 6 ++++++
>> drivers/virtio/virtio.c | 9 +++++++++
>> include/linux/virtio.h | 2 ++
>> 3 files changed, 17 insertions(+)
>>
>> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
>> index 87b2d024e75a..3f04ad09650f 100644
>> --- a/arch/s390/mm/init.c
>> +++ b/arch/s390/mm/init.c
>> @@ -46,6 +46,7 @@
>> #include <asm/kasan.h>
>> #include <asm/dma-mapping.h>
>> #include <asm/uv.h>
>> +#include <linux/virtio.h>
>>
>> pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
>>
>> @@ -162,6 +163,11 @@ bool force_dma_unencrypted(struct device *dev)
>> return is_prot_virt_guest();
>> }
>>
>> +int arch_needs_iommu_platform(struct virtio_device *dev)
>> +{
>> + return is_prot_virt_guest();
>> +}
>> +
>> /* protected virtualization */
>> static void pv_init(void)
>> {
>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>> index a977e32a88f2..30091089bee8 100644
>> --- a/drivers/virtio/virtio.c
>> +++ b/drivers/virtio/virtio.c
>> @@ -167,6 +167,11 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status)
>> }
>> EXPORT_SYMBOL_GPL(virtio_add_status);
>>
>> +int __weak arch_needs_iommu_platform(struct virtio_device *dev)
>> +{
>> + return 0;
>> +}
>> +
>> int virtio_finalize_features(struct virtio_device *dev)
>> {
>> int ret = dev->config->finalize_features(dev);
>> @@ -179,6 +184,10 @@ int virtio_finalize_features(struct virtio_device *dev)
>> if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
>> return 0;
>>
>> + if (arch_needs_iommu_platform(dev) &&
>> + !virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM))
>> + return -EIO;
>> +
>> virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
>> status = dev->config->get_status(dev);
>> if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
>> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
>> index a493eac08393..2c46b310c38c 100644
>> --- a/include/linux/virtio.h
>> +++ b/include/linux/virtio.h
>> @@ -195,4 +195,6 @@ void unregister_virtio_driver(struct virtio_driver *drv);
>> #define module_virtio_driver(__virtio_driver) \
>> module_driver(__virtio_driver, register_virtio_driver, \
>> unregister_virtio_driver)
>> +
>> +int arch_needs_iommu_platform(struct virtio_device *dev);
>> #endif /* _LINUX_VIRTIO_H */
>>
--
Pierre Morel
IBM Lab Boeblingen
next prev parent reply other threads:[~2020-06-16 7:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-15 12:39 [PATCH v2 0/1] s390: virtio: let's arch choose to accept devices without IOMMU feature Pierre Morel
2020-06-15 12:39 ` [PATCH v2 1/1] s390: virtio: let arch " Pierre Morel
2020-06-16 6:22 ` Jason Wang
2020-06-16 7:33 ` Pierre Morel
2020-06-16 6:55 ` Christian Borntraeger
2020-06-16 7:35 ` Pierre Morel [this message]
2020-06-16 12:21 ` Cornelia Huck
2020-06-16 9:52 ` Halil Pasic
2020-06-16 10:52 ` Pierre Morel
2020-06-16 11:57 ` Halil Pasic
2020-06-16 12:17 ` Cornelia Huck
2020-06-16 13:41 ` Pierre Morel
2020-06-16 13:50 ` Cornelia Huck
2020-06-16 12:20 ` Cornelia Huck
2020-06-16 13:36 ` Pierre Morel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=a93bf169-55ca-2a77-f9a5-b27bf18176e2@linux.ibm.com \
--to=pmorel@linux.ibm.com \
--cc=borntraeger@de.ibm.com \
--cc=cohuck@redhat.com \
--cc=frankja@linux.ibm.com \
--cc=jasowang@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=mst@redhat.com \
--cc=pasic@linux.ibm.com \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).