similar to: [RFC 0/4] Virtio uses DMA API for all devices

On Fri, Jul 20, 2018 at 09:29:41AM +0530, Anshuman Khandual wrote: >Subject: Re: [RFC 4/4] virtio: Add platform specific DMA API translation for > virito devices s/virito/virtio/ > This adds a hook which a platform can define in order to allow it to > override virtio device's DMA OPS irrespective of whether it has the > flag VIRTIO_F_IOMMU_PLATFORM set or not. We want to use

On Fri, Jul 20, 2018 at 09:29:41AM +0530, Anshuman Khandual wrote: >Subject: Re: [RFC 4/4] virtio: Add platform specific DMA API translation for > virito devices s/virito/virtio/ > This adds a hook which a platform can define in order to allow it to > override virtio device's DMA OPS irrespective of whether it has the > flag VIRTIO_F_IOMMU_PLATFORM set or not. We want to use

On 07/20/2018 06:46 PM, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: >> This patch series is the follow up on the discussions we had before about >> the RFC titled [RFC,V2] virtio: Add platform specific DMA API translation >> for virito devices (https://patchwork.kernel.org/patch/10417371/). There >> were suggestions

On 07/20/2018 06:46 PM, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: >> This patch series is the follow up on the discussions we had before about >> the RFC titled [RFC,V2] virtio: Add platform specific DMA API translation >> for virito devices (https://patchwork.kernel.org/patch/10417371/). There >> were suggestions

On 07/20/2018 09:29 AM, Anshuman Khandual 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

On 07/20/2018 09:29 AM, Anshuman Khandual 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

On 2018?08?03? 04:55, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: >> This patch series is the follow up on the discussions we had before about >> the RFC titled [RFC,V2] virtio: Add platform specific DMA API translation >> for virito devices (https://patchwork.kernel.org/patch/10417371/). There >> were suggestions about

On 2018?08?03? 04:55, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: >> This patch series is the follow up on the discussions we had before about >> the RFC titled [RFC,V2] virtio: Add platform specific DMA API translation >> for virito devices (https://patchwork.kernel.org/patch/10417371/). There >> were suggestions about

There are certian platforms which would like to use SWIOTLB based DMA API for bouncing purpose without actually requiring an IOMMU back end. But the virtio core does not allow such mechanism. Right now DMA MAP API is only selected for devices which have an IOMMU and then the QEMU/host back end will process all incoming SG buffer addresses as IOVA instead of simple GPA which is the case for simple

There are certian platforms which would like to use SWIOTLB based DMA API for bouncing purpose without actually requiring an IOMMU back end. But the virtio core does not allow such mechanism. Right now DMA MAP API is only selected for devices which have an IOMMU and then the QEMU/host back end will process all incoming SG buffer addresses as IOVA instead of simple GPA which is the case for simple

On Thu, Apr 05, 2018 at 08:09:30PM +0530, Anshuman Khandual wrote: > On 04/05/2018 04:26 PM, Anshuman Khandual wrote: > > There are certian platforms which would like to use SWIOTLB based DMA API > > for bouncing purpose without actually requiring an IOMMU back end. But the > > virtio core does not allow such mechanism. Right now DMA MAP API is only > > selected for

On Thu, Apr 05, 2018 at 08:09:30PM +0530, Anshuman Khandual wrote: > On 04/05/2018 04:26 PM, Anshuman Khandual wrote: > > There are certian platforms which would like to use SWIOTLB based DMA API > > for bouncing purpose without actually requiring an IOMMU back end. But the > > virtio core does not allow such mechanism. Right now DMA MAP API is only > > selected for

On 07/23/2018 02:38 PM, Michael S. Tsirkin wrote: > On Mon, Jul 23, 2018 at 11:58:23AM +0530, Anshuman Khandual wrote: >> On 07/20/2018 06:46 PM, Michael S. Tsirkin wrote: >>> On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: >>>> This patch series is the follow up on the discussions we had before about >>>> the RFC titled [RFC,V2] virtio:

On 07/23/2018 02:38 PM, Michael S. Tsirkin wrote: > On Mon, Jul 23, 2018 at 11:58:23AM +0530, Anshuman Khandual wrote: >> On 07/20/2018 06:46 PM, Michael S. Tsirkin wrote: >>> On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: >>>> This patch series is the follow up on the discussions we had before about >>>> the RFC titled [RFC,V2] virtio:

> +/* > + * Virtio direct mapping DMA API operations structure > + * > + * This defines DMA API structure for all virtio devices which would not > + * either bring in their own DMA OPS from architecture or they would not > + * like to use architecture specific IOMMU based DMA OPS because QEMU > + * expects GPA instead of an IOVA in absence of VIRTIO_F_IOMMU_PLATFORM. > + */

This adds a hook which a platform can define in order to allow it to force the use of the DMA API for all virtio devices even if they don't have the VIRTIO_F_IOMMU_PLATFORM flag set. We want to use this to do bounce-buffering of data on the new secure pSeries platform, currently under development, where a KVM host cannot access all of the memory space of a secure KVM guest. The host can only

This adds a hook which a platform can define in order to allow it to force the use of the DMA API for all virtio devices even if they don't have the VIRTIO_F_IOMMU_PLATFORM flag set. We want to use this to do bounce-buffering of data on the new secure pSeries platform, currently under development, where a KVM host cannot access all of the memory space of a secure KVM guest. The host can only

On 07/20/2018 06:45 PM, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 09:29:41AM +0530, Anshuman Khandual wrote: >> Subject: Re: [RFC 4/4] virtio: Add platform specific DMA API translation for >> virito devices > > s/virito/virtio/ Oops, will fix it. Thanks for pointing out. > >> This adds a hook which a platform can define in order to allow it to >>

This adds a hook which a platform can define in order to allow it to override virtio device's DMA OPS irrespective of whether it has the flag VIRTIO_F_IOMMU_PLATFORM set or not. We want to use this to do bounce-buffering of data on the new secure pSeries platform, currently under development, where a KVM host cannot access all of the memory space of a secure KVM guest. The host can only

Hi Anshuman, On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: > This patch series is the follow up on the discussions we had before about > the RFC titled [RFC,V2] virtio: Add platform specific DMA API translation > for virito devices (https://patchwork.kernel.org/patch/10417371/). There > were suggestions about doing away with two different paths of transactions