search for: virtio_direct_dma_op

...andual wrote: > Now that virtio core always needs all virtio devices to have DMA OPS, we > need to make sure that the structure it points is the right one. In the > absence of VIRTIO_F_IOMMU_PLATFORM flag QEMU expects GPA from guest kernel. > In such case, virtio device must use default virtio_direct_dma_ops DMA OPS > structure which transforms scatter gather buffer addresses as GPA. This > DMA OPS override must happen as early as possible during virtio device > initializatin sequence before virtio core starts using given device's DMA > OPS callbacks for I/O transactions. This change d...

...andual wrote: > Now that virtio core always needs all virtio devices to have DMA OPS, we > need to make sure that the structure it points is the right one. In the > absence of VIRTIO_F_IOMMU_PLATFORM flag QEMU expects GPA from guest kernel. > In such case, virtio device must use default virtio_direct_dma_ops DMA OPS > structure which transforms scatter gather buffer addresses as GPA. This > DMA OPS override must happen as early as possible during virtio device > initializatin sequence before virtio core starts using given device's DMA > OPS callbacks for I/O transactions. This change d...

...gt; Now that virtio core always needs all virtio devices to have DMA OPS, we > > need to make sure that the structure it points is the right one. In the > > absence of VIRTIO_F_IOMMU_PLATFORM flag QEMU expects GPA from guest kernel. > > In such case, virtio device must use default virtio_direct_dma_ops DMA OPS > > structure which transforms scatter gather buffer addresses as GPA. This > > DMA OPS override must happen as early as possible during virtio device > > initializatin sequence before virtio core starts using given device's DMA > > OPS callbacks for I/O transac...

> +const struct dma_map_ops virtio_direct_dma_ops; This belongs into a header if it is non-static. If you only use it in this file anyway please mark it static and avoid a forward declaration. > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); > @@ -174,6...

...turn queue; queue is a very odd name in a generic memory allocator. > +void virtio_direct_free(struct device *dev, size_t size, void *vaddr, > + dma_addr_t dma_addr, unsigned long attrs) > +{ > + free_pages_exact(vaddr, PAGE_ALIGN(size)); > +} > + > +const struct dma_map_ops virtio_direct_dma_ops = { > + .alloc = virtio_direct_alloc, > + .free = virtio_direct_free, > + .map_page = virtio_direct_map_page, > + .unmap_page = virtio_direct_unmap_page, > + .mapping_error = virtio_direct_mapping_error, > +}; This is missing a dma_map_sg implementation. In general this...

> > + > > + 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 break. I agree about avoid pointless gotos here, but we can do things perfectly...

Now that virtio core always needs all virtio devices to have DMA OPS, we need to make sure that the structure it points is the right one. In the absence of VIRTIO_F_IOMMU_PLATFORM flag QEMU expects GPA from guest kernel. In such case, virtio device must use default virtio_direct_dma_ops DMA OPS structure which transforms scatter gather buffer addresses as GPA. This DMA OPS override must happen as early as possible during virtio device initializatin sequence before virtio core starts using given device's DMA OPS callbacks for I/O transactions. This change detects device's...

...s_addr)) { + free_pages_exact(queue, PAGE_ALIGN(size)); + return NULL; + } + } + return queue; +} + +void virtio_direct_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs) +{ + free_pages_exact(vaddr, PAGE_ALIGN(size)); +} + +const struct dma_map_ops virtio_direct_dma_ops = { + .alloc = virtio_direct_alloc, + .free = virtio_direct_free, + .map_page = virtio_direct_map_page, + .unmap_page = virtio_direct_unmap_page, + .mapping_error = virtio_direct_mapping_error, +}; +EXPORT_SYMBOL(virtio_direct_dma_ops); diff --git a/drivers/virtio/virtio_pci_common.h b/driv...

...l.org/patch/10417371/). There were suggestions about doing away with two different paths of transactions with the host/QEMU, first being the direct GPA and the other being the DMA API based translations. First patch attempts to create a direct GPA mapping based DMA operations structure called 'virtio_direct_dma_ops' with exact same implementation of the direct GPA path which virtio core currently has but just wrapped in a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the existing semantics. The secon...

...l.org/patch/10417371/). There were suggestions about doing away with two different paths of transactions with the host/QEMU, first being the direct GPA and the other being the DMA API based translations. First patch attempts to create a direct GPA mapping based DMA operations structure called 'virtio_direct_dma_ops' with exact same implementation of the direct GPA path which virtio core currently has but just wrapped in a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the existing semantics. The secon...

...s if required */ > +} > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index 6b13987..432c332 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -168,6 +168,12 @@ EXPORT_SYMBOL_GPL(virtio_add_status); > > const struct dma_map_ops virtio_direct_dma_ops; > > +#ifndef platform_override_dma_ops > +static inline void platform_override_dma_ops(struct virtio_device *vdev) > +{ > +} > +#endif > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); >...

...s if required */ > +} > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index 6b13987..432c332 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -168,6 +168,12 @@ EXPORT_SYMBOL_GPL(virtio_add_status); > > const struct dma_map_ops virtio_direct_dma_ops; > > +#ifndef platform_override_dma_ops > +static inline void platform_override_dma_ops(struct virtio_device *vdev) > +{ > +} > +#endif > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); >...

...ns about doing away with two different paths of transactions >> with the host/QEMU, first being the direct GPA and the other being the DMA >> API based translations. >> >> First patch attempts to create a direct GPA mapping based DMA operations >> structure called 'virtio_direct_dma_ops' with exact same implementation >> of the direct GPA path which virtio core currently has but just wrapped in >> a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of >> the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the &g...

...ns about doing away with two different paths of transactions >> with the host/QEMU, first being the direct GPA and the other being the DMA >> API based translations. >> >> First patch attempts to create a direct GPA mapping based DMA operations >> structure called 'virtio_direct_dma_ops' with exact same implementation >> of the direct GPA path which virtio core currently has but just wrapped in >> a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of >> the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the &g...

...;> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c >> index 6b13987..432c332 100644 >> --- a/drivers/virtio/virtio.c >> +++ b/drivers/virtio/virtio.c >> @@ -168,6 +168,12 @@ EXPORT_SYMBOL_GPL(virtio_add_status); >> >> const struct dma_map_ops virtio_direct_dma_ops; >> >> +#ifndef platform_override_dma_ops >> +static inline void platform_override_dma_ops(struct virtio_device *vdev) >> +{ >> +} >> +#endif >> + >> int virtio_finalize_features(struct virtio_device *dev) >> { >> int ret = dev->...

...> were suggestions about doing away with two different paths of transactions > with the host/QEMU, first being the direct GPA and the other being the DMA > API based translations. > > First patch attempts to create a direct GPA mapping based DMA operations > structure called 'virtio_direct_dma_ops' with exact same implementation > of the direct GPA path which virtio core currently has but just wrapped in > a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of > the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the > existing...

...> were suggestions about doing away with two different paths of transactions > with the host/QEMU, first being the direct GPA and the other being the DMA > API based translations. > > First patch attempts to create a direct GPA mapping based DMA operations > structure called 'virtio_direct_dma_ops' with exact same implementation > of the direct GPA path which virtio core currently has but just wrapped in > a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of > the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the > existing...

...fferent paths of transactions > > > with the host/QEMU, first being the direct GPA and the other being the DMA > > > API based translations. > > > > > > First patch attempts to create a direct GPA mapping based DMA operations > > > structure called 'virtio_direct_dma_ops' with exact same implementation > > > of the direct GPA path which virtio core currently has but just wrapped in > > > a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of > > > the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag...

...ns about doing away with two different paths of transactions >> with the host/QEMU, first being the direct GPA and the other being the DMA >> API based translations. >> >> First patch attempts to create a direct GPA mapping based DMA operations >> structure called 'virtio_direct_dma_ops' with exact same implementation >> of the direct GPA path which virtio core currently has but just wrapped in >> a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of >> the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the &g...

...ns about doing away with two different paths of transactions >> with the host/QEMU, first being the direct GPA and the other being the DMA >> API based translations. >> >> First patch attempts to create a direct GPA mapping based DMA operations >> structure called 'virtio_direct_dma_ops' with exact same implementation >> of the direct GPA path which virtio core currently has but just wrapped in >> a DMA API format. Virtio core must use 'virtio_direct_dma_ops' instead of >> the arch default in absence of VIRTIO_F_IOMMU_PLATFORM flag to preserve the &g...