From: Tom Lendacky <thomas.lendacky@amd.com>
To: Pierre Morel <pmorel@linux.ibm.com>, linux-kernel@vger.kernel.org
Cc: pasic@linux.ibm.com, borntraeger@de.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,
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: Wed, 17 Jun 2020 08:36:12 -0500 [thread overview]
Message-ID: <e5204218-6e93-8713-6056-2a62531c310e@amd.com> (raw)
In-Reply-To: <1592390637-17441-2-git-send-email-pmorel@linux.ibm.com>
On 6/17/20 5:43 AM, 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: Jason Wang <jasowang@redhat.com>
> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> arch/s390/mm/init.c | 6 ++++++
> drivers/virtio/virtio.c | 22 ++++++++++++++++++++++
> include/linux/virtio.h | 2 ++
> 3 files changed, 30 insertions(+)
>
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 6dc7c3b60ef6..215070c03226 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -45,6 +45,7 @@
> #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);
>
> @@ -161,6 +162,11 @@ bool force_dma_unencrypted(struct device *dev)
> return is_prot_virt_guest();
> }
>
> +int arch_needs_virtio_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..aa8e01104f86 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status)
> }
> EXPORT_SYMBOL_GPL(virtio_add_status);
>
> +/*
> + * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing
> + * features for VIRTIO device dev
> + * @dev: the VIRTIO device being added
> + *
> + * Permits the platform to provide architecture specific functionality when
> + * devices features are finalized. This is the default implementation.
> + * Architecture implementations can override this.
> + */
> +
> +int __weak arch_needs_virtio_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 +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)) {
Just a style nit, but the "!virtio..." should be directly under the
"arch_...", not tabbed out.
Thanks,
Tom
> + dev_warn(&dev->dev,
> + "virtio: device must provide VIRTIO_F_IOMMU_PLATFORM\n");
> + return -ENODEV;
> + }
> +
> 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..e8526ae3463e 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_virtio_iommu_platform(struct virtio_device *dev);
> #endif /* _LINUX_VIRTIO_H */
>
next prev parent reply other threads:[~2020-06-17 13:36 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 [this message]
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
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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