search for: virtio_has_iommu_quirk

....e8799ab0c753 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -141,7 +141,7 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, struct virtio_gpu_mem_entry **ents, unsigned int *nents) { - bool use_dma_api = !virtio_has_iommu_quirk(vgdev->vdev); + bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev); struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); struct scatterlist *sg; int si, ret; diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5d9952..53af60d...

Use generic names for the quirks to make it clear it is not just about the IOMMU, it's about DMA access in general. changes from v1: added patch 2 Michael S. Tsirkin (2): virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORM virtio: virtio_has_iommu_quirk -> virtio_has_dma_quirk arch/um/drivers/virtio_uml.c | 2 +- drivers/gpu/drm/virtio/virtgpu_object.c | 2 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++-- drivers/vdpa/ifcvf/ifcvf_base.h | 2 +- drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++-- drivers/vhost/net.c...

...rride_dma_ops(struct virtio_device *vdev) > +{ > +} > +#endif > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); > @@ -179,6 +185,7 @@ int virtio_finalize_features(struct virtio_device *dev) > if (virtio_has_iommu_quirk(dev)) > set_dma_ops(dev->dev.parent, &virtio_direct_dma_ops); > > + platform_override_dma_ops(dev); Is there a single place where virtio_has_iommu_quirk is called now? If so, we could put this into virtio_has_iommu_quirk then. > if (!virtio_has_feature(dev, VIRTIO_F_VERS...

...rride_dma_ops(struct virtio_device *vdev) > +{ > +} > +#endif > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); > @@ -179,6 +185,7 @@ int virtio_finalize_features(struct virtio_device *dev) > if (virtio_has_iommu_quirk(dev)) > set_dma_ops(dev->dev.parent, &virtio_direct_dma_ops); > > + platform_override_dma_ops(dev); Is there a single place where virtio_has_iommu_quirk is called now? If so, we could put this into virtio_has_iommu_quirk then. > if (!virtio_has_feature(dev, VIRTIO_F_VERS...

...vdev) >> +{ >> +} >> +#endif >> + >> int virtio_finalize_features(struct virtio_device *dev) >> { >> int ret = dev->config->finalize_features(dev); >> @@ -179,6 +185,7 @@ int virtio_finalize_features(struct virtio_device *dev) >> if (virtio_has_iommu_quirk(dev)) >> set_dma_ops(dev->dev.parent, &virtio_direct_dma_ops); >> >> + platform_override_dma_ops(dev); > > Is there a single place where virtio_has_iommu_quirk is called now? Not other than this one. But in the proposed implementation of platform_override_dma_o...

...oid a forward declaration. > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); > @@ -174,6 +176,9 @@ int virtio_finalize_features(struct virtio_device *dev) > if (ret) > return ret; > > + if (virtio_has_iommu_quirk(dev)) > + set_dma_ops(dev->dev.parent, &virtio_direct_dma_ops); This needs a big fat comment explaining what is going on here. Also not new, but I find the existance of virtio_has_iommu_quirk and its name horribly confusing. It might be better to open code it here once only a single c...

...the code block for XEN guests which forced the use of DMA API all the time irrespective of VIRTIO_F_IOMMU_PLATFORM flag on the device. Here is what I have removed with patch 2/4 which breaks the existing semantics on XEN guests. -static bool vring_use_dma_api(struct virtio_device *vdev) -{ - if (!virtio_has_iommu_quirk(vdev)) - return true; - - /* Otherwise, we are left to guess. */ - /* - * In theory, it's possible to have a buggy QEMU-supposed - * emulated Q35 IOMMU and Xen enabled at the same time. On - * such a configuration, virtio has never worked and will - * not work without an even larger kludg...

...the code block for XEN guests which forced the use of DMA API all the time irrespective of VIRTIO_F_IOMMU_PLATFORM flag on the device. Here is what I have removed with patch 2/4 which breaks the existing semantics on XEN guests. -static bool vring_use_dma_api(struct virtio_device *vdev) -{ - if (!virtio_has_iommu_quirk(vdev)) - return true; - - /* Otherwise, we are left to guess. */ - /* - * In theory, it's possible to have a buggy QEMU-supposed - * emulated Q35 IOMMU and Xen enabled at the same time. On - * such a configuration, virtio has never worked and will - * not work without an even larger kludg...

...DMA operations > > structure. > > > > Signed-off-by: Anshuman Khandual <khandual at linux.vnet.ibm.com> > > + "Michael S. Tsirkin" <mst at redhat.com> I'm confused by this. static bool vring_use_dma_api(struct virtio_device *vdev) { if (!virtio_has_iommu_quirk(vdev)) return true; Why doesn't setting VIRTIO_F_IOMMU_PLATFORM on the hypervisor side sufficient?

...DMA operations > > structure. > > > > Signed-off-by: Anshuman Khandual <khandual at linux.vnet.ibm.com> > > + "Michael S. Tsirkin" <mst at redhat.com> I'm confused by this. static bool vring_use_dma_api(struct virtio_device *vdev) { if (!virtio_has_iommu_quirk(vdev)) return true; Why doesn't setting VIRTIO_F_IOMMU_PLATFORM on the hypervisor side sufficient?

...rs/gpu/drm/virtio/virtgpu_object.c @@ -121,6 +121,49 @@ struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev, return &bo->base.base; } +static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, + struct virtio_gpu_object *bo) +{ + bool use_dma_api = !virtio_has_iommu_quirk(vgdev->vdev); + struct scatterlist *sg; + int si, ret; + + ret = drm_gem_shmem_pin(&bo->base.base); + if (ret < 0) + return -EINVAL; + + bo->pages = drm_gem_shmem_get_sg_table(&bo->base.base); + if (bo->pages == NULL) { + drm_gem_shmem_unpin(&bo->base.base); + re...

...ux/virtio_config.h b/include/linux/virtio_config.h index 6e6cb0c..26c155b 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -149,6 +149,19 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev, return __virtio_test_bit(vdev, fbit); } +/** + * virtio_has_iommu_quirk - determine whether this device has the iommu quirk + * @vdev: the device + */ +static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev) +{ + /* + * Note the reverse polarity of the quirk feature (compared to most + * other features), this is for compatibility with legacy syste...

...rs/gpu/drm/virtio/virtgpu_object.c @@ -121,6 +121,49 @@ struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev, return &bo->base.base; } +static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, + struct virtio_gpu_object *bo) +{ + bool use_dma_api = !virtio_has_iommu_quirk(vgdev->vdev); + struct scatterlist *sg; + int si, ret; + + ret = drm_gem_shmem_pin(&bo->base.base); + if (ret < 0) + return -EINVAL; + + bo->pages = drm_gem_shmem_get_sg_table(&bo->base.base); + if (bo->pages == NULL) { + drm_gem_shmem_unpin(&bo->base.base); + re...

...ux/virtio_config.h b/include/linux/virtio_config.h index 6e6cb0c..26c155b 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -149,6 +149,19 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev, return __virtio_test_bit(vdev, fbit); } +/** + * virtio_has_iommu_quirk - determine whether this device has the iommu quirk + * @vdev: the device + */ +static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev) +{ + /* + * Note the reverse polarity of the quirk feature (compared to most + * other features), this is for compatibility with legacy syste...

...m_object *virtio_gpu_create_object(struct drm_device *dev, return &bo->base.base; } +static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, + struct virtio_gpu_object *bo, + struct virtio_gpu_mem_entry **ents, + unsigned int *nents) +{ + bool use_dma_api = !virtio_has_iommu_quirk(vgdev->vdev); + struct scatterlist *sg; + int si, ret; + + ret = drm_gem_shmem_pin(&bo->base.base); + if (ret < 0) + return -EINVAL; + + bo->pages = drm_gem_shmem_get_sg_table(&bo->base.base); + if (!bo->pages) { + drm_gem_shmem_unpin(&bo->base.base); + return -E...

...4 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -144,6 +144,10 @@ struct vring_virtqueue { static bool vring_use_dma_api(struct virtio_device *vdev) { + /* Use DMA API even for virtio devices without an IOMMU */ + if (is_virtio_dma_platform()) + return true; + if (!virtio_has_iommu_quirk(vdev)) return true; diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 988c7355bc22..d8bb83d753ea 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -200,6 +200,8 @@ static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) int register_virt...

...4 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -144,6 +144,10 @@ struct vring_virtqueue { static bool vring_use_dma_api(struct virtio_device *vdev) { + /* Use DMA API even for virtio devices without an IOMMU */ + if (is_virtio_dma_platform()) + return true; + if (!virtio_has_iommu_quirk(vdev)) return true; diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 988c7355bc22..d8bb83d753ea 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -200,6 +200,8 @@ static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) int register_virt...

...IO_F_ACCESS_PLATFORM: break; case VIRTIO_F_RING_PACKED: break; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index bb4cc4910750..f2cc2a0df174 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -171,7 +171,7 @@ static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev) * Note the reverse polarity of the quirk feature (compared to most * other features), this is for compatibility with legacy systems. */ - return !virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); + return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM...

> > + > > + if (xen_domain()) > > + goto skip_override; > > + > > + if (virtio_has_iommu_quirk(dev)) > > + set_dma_ops(dev->dev.parent, &virtio_direct_dma_ops); > > + > > + skip_override: > > + > > I prefer normal if scoping as opposed to goto spaghetti pls. > Better yet move vring_use_dma_api here and use it. > Less of a chance something will bre...

...r; struct eventfd_ctx *req_trigger; struct list_head dummy_resources_list; }; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 26c155b..6b0f416 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -159,7 +159,17 @@ static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev) * Note the reverse polarity of the quirk feature (compared to most * other features), this is for compatibility with legacy systems. */ - return !virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); + if (virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) +...