similar to: [RFC] virtio: Use DMA MAP API for devices without an IOMMU

On Thu, Apr 5, 2018 at 8:56 PM, Anshuman Khandual <khandual at linux.vnet.ibm.com> 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 devices which have an IOMMU and then the

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

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

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 with the host/QEMU, first being the direct GPA and the other being the DMA API based translations.

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 with the host/QEMU, first being the direct GPA and the other being the DMA API based translations.

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 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

On Wed, 2018-05-23 at 21:50 +0300, Michael S. Tsirkin wrote: > I re-read that discussion and I'm still unclear on the > original question, since I got several apparently > conflicting answers. > > I asked: > > Why isn't setting VIRTIO_F_IOMMU_PLATFORM on the > hypervisor side sufficient? I thought I had replied to this... There are a couple of reasons: -

On Wed, 2018-05-23 at 21:50 +0300, Michael S. Tsirkin wrote: > I re-read that discussion and I'm still unclear on the > original question, since I got several apparently > conflicting answers. > > I asked: > > Why isn't setting VIRTIO_F_IOMMU_PLATFORM on the > hypervisor side sufficient? I thought I had replied to this... There are a couple of reasons: -

On 06/16/2016 11:07 AM, Minchan Kim wrote: > On Thu, Jun 16, 2016 at 09:12:07AM +0530, Anshuman Khandual wrote: >> On 06/16/2016 05:56 AM, Minchan Kim wrote: >>> On Wed, Jun 15, 2016 at 12:15:04PM +0530, Anshuman Khandual wrote: >>>> On 06/15/2016 08:02 AM, Minchan Kim wrote: >>>>> Hi, >>>>> >>>>> On Mon, Jun 13, 2016 at

On 06/16/2016 11:07 AM, Minchan Kim wrote: > On Thu, Jun 16, 2016 at 09:12:07AM +0530, Anshuman Khandual wrote: >> On 06/16/2016 05:56 AM, Minchan Kim wrote: >>> On Wed, Jun 15, 2016 at 12:15:04PM +0530, Anshuman Khandual wrote: >>>> On 06/15/2016 08:02 AM, Minchan Kim wrote: >>>>> Hi, >>>>> >>>>> On Mon, Jun 13, 2016 at

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

This series renames pmd_mknotpresent() as pmd_mknotvalid(). Before that it drops an existing pmd_mknotpresent() definition from powerpc platform which was never required as it defines it's pmdp_invalidate() through subscribing __HAVE_ARCH_PMDP_INVALIDATE. This does not create any functional change. This rename was suggested by Catalin during a previous discussion while we were trying to

On 06/16/2016 05:56 AM, Minchan Kim wrote: > On Wed, Jun 15, 2016 at 12:15:04PM +0530, Anshuman Khandual wrote: >> On 06/15/2016 08:02 AM, Minchan Kim wrote: >>> Hi, >>> >>> On Mon, Jun 13, 2016 at 03:08:19PM +0530, Anshuman Khandual wrote: >>>>> On 05/31/2016 05:31 AM, Minchan Kim wrote: >>>>>>> @@ -791,6 +921,7 @@ static int

On 06/16/2016 05:56 AM, Minchan Kim wrote: > On Wed, Jun 15, 2016 at 12:15:04PM +0530, Anshuman Khandual wrote: >> On 06/15/2016 08:02 AM, Minchan Kim wrote: >>> Hi, >>> >>> On Mon, Jun 13, 2016 at 03:08:19PM +0530, Anshuman Khandual wrote: >>>>> On 05/31/2016 05:31 AM, Minchan Kim wrote: >>>>>>> @@ -791,6 +921,7 @@ static int