similar to: [RFC PATCH] drm/virtio: Export resource handles via DMA-buf API

Hi, > To seamlessly enable buffer sharing with drivers using such frameworks, > make the virtio-gpu driver expose the resource handle as the DMA address > of the buffer returned from the DMA-buf mapping operation. Arguably, the > resource handle is a kind of DMA address already, as it is the buffer > identifier that the device needs to access the backing memory, which is >

Hi, > > No. DMA master address space in virtual machines is pretty much the > > same it is on physical machines. So, on x86 without iommu, identical > > to (guest) physical address space. You can't re-define it like that. > > That's not true. Even on x86 without iommu the DMA address space can > be different from the physical address space. On a standard pc

On Sat, Oct 05, 2019 at 02:41:54PM +0900, Tomasz Figa wrote: > Hi Daniel, Gerd, > > On Tue, Sep 17, 2019 at 10:23 PM Daniel Vetter <daniel at ffwll.ch> wrote: > > > > On Thu, Sep 12, 2019 at 06:41:21PM +0900, Tomasz Figa wrote: > > > This patch is an early RFC to judge the direction we are following in > > > our virtualization efforts in Chrome OS. The

On Tue, Oct 08, 2019 at 07:49:39PM +0900, Tomasz Figa wrote: > On Tue, Oct 8, 2019 at 7:03 PM Daniel Vetter <daniel at ffwll.ch> wrote: > > > > On Sat, Oct 05, 2019 at 02:41:54PM +0900, Tomasz Figa wrote: > > > Hi Daniel, Gerd, > > > > > > On Tue, Sep 17, 2019 at 10:23 PM Daniel Vetter <daniel at ffwll.ch> wrote: > > > > > >

On Wed, Oct 16, 2019 at 12:19:02PM +0900, Tomasz Figa wrote: > On Wed, Oct 9, 2019 at 12:04 AM Daniel Vetter <daniel at ffwll.ch> wrote: > > > > On Tue, Oct 08, 2019 at 07:49:39PM +0900, Tomasz Figa wrote: > > > On Tue, Oct 8, 2019 at 7:03 PM Daniel Vetter <daniel at ffwll.ch> wrote: > > > > > > > > On Sat, Oct 05, 2019 at 02:41:54PM

On Thu, Sep 12, 2019 at 06:41:21PM +0900, Tomasz Figa wrote: > This patch is an early RFC to judge the direction we are following in > our virtualization efforts in Chrome OS. The purpose is to start a > discussion on how to handle buffer sharing between multiple virtio > devices. > > On a side note, we are also working on a virtio video decoder interface > and

Hi, > up later when given a buffer index. But we would still need to make > the DMA-buf itself importable. For virtio-gpu I guess that would mean > returning an sg_table backed by the shadow buffer pages. The virtio-gpu driver in drm-misc-next supports dma-buf exports. cheers, Gerd

After switching DMA attributes to unsigned long it is easier to just compare the bits. Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com> --- Documentation/DMA-API.txt | 4 +-- arch/arc/mm/dma.c | 4 +-- arch/arm/mm/dma-mapping.c | 36 ++++++++++++-------------- arch/arm/xen/mm.c

On Thu, May 28, 2020 at 06:00:44PM -0600, Logan Gunthorpe wrote: > > This issue is most likely in the i915 driver and is most likely caused by the driver not respecting the return value of the dma_map_ops::map_sg function. You can see the driver ignoring the return value here: > >

On Thu, 27 Aug 2020 at 22:36, Logan Gunthorpe <logang at deltatee.com> wrote: > > > > On 2020-08-23 6:04 p.m., Tom Murphy wrote: > > I have added a check for the sg_dma_len == 0 : > > """ > > } __sgt_iter(struct scatterlist *sgl, bool dma) { > > struct sgt_iter s = { .sgp = sgl }; > > > > + if (sgl &&

Allow the dma-iommu api to use bounce buffers for untrusted devices. This is a copy of the intel bounce buffer code. Signed-off-by: Tom Murphy <murphyt7 at tcd.ie> --- drivers/iommu/dma-iommu.c | 93 ++++++++++++++++++++++++++++++++------- drivers/iommu/iommu.c | 10 +++++ include/linux/iommu.h | 9 +++- 3 files changed, 95 insertions(+), 17 deletions(-) diff --git

On Thu, Aug 20, 2020 at 7:02 AM Christoph Hellwig <hch at lst.de> wrote: > > On Wed, Aug 19, 2020 at 03:07:04PM +0100, Robin Murphy wrote: > >> FWIW, I asked back in time what the plan is for non-coherent > >> allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > >> dma_sync_*() was supposed to be the right thing to go with. [2] The > >> same

ops __finalise_sg Disable combining sg segments in the dma-iommu api. Combining the sg segments exposes a bug in the intel i915 driver which causes visual artifacts and the screen to freeze. This is most likely because of how the i915 handles the returned list. It probably doesn't respect the returned value specifying the number of elements in the list and instead depends on the previous

On Sat, 21 Dec 2019, Tom Murphy <murphyt7 at tcd.ie> wrote: > This patchset converts the intel iommu driver to the dma-iommu api. > > While converting the driver I exposed a bug in the intel i915 driver > which causes a huge amount of artifacts on the screen of my > laptop. You can see a picture of it here: >

Hi Tom, On 2019-12-21 15:03, Tom Murphy wrote: > This patchset converts the intel iommu driver to the dma-iommu api. > > While converting the driver I exposed a bug in the intel i915 driver which causes a huge amount of artifacts on the screen of my laptop. You can see a picture of it here: > https://github.com/pippy360/kernelPatches/blob/master/IMG_20191219_225922.jpg > >

Split out subsystem specific changes for easier reviews. This will be squashed with main commit. Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com> --- drivers/media/platform/sti/bdisp/bdisp-hw.c | 26 +++++++--------------- drivers/media/v4l2-core/videobuf2-dma-contig.c | 30 +++++++++++--------------- drivers/media/v4l2-core/videobuf2-dma-sg.c | 19 ++++------------

On 2019-12-23 10:37 am, Jani Nikula wrote: > On Sat, 21 Dec 2019, Tom Murphy <murphyt7 at tcd.ie> wrote: >> This patchset converts the intel iommu driver to the dma-iommu api. >> >> While converting the driver I exposed a bug in the intel i915 driver >> which causes a huge amount of artifacts on the screen of my >> laptop. You can see a picture of it here:

On Wed, 9 Sep 2020 at 13:56, Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com> wrote: > > > On 09/09/2020 10:16, Tvrtko Ursulin wrote: > > On 08/09/2020 23:43, Tom Murphy wrote: > >> On Tue, 8 Sep 2020 at 16:56, Tvrtko Ursulin > >> <tvrtko.ursulin at linux.intel.com> wrote: > >>> On 08/09/2020 16:44, Logan Gunthorpe wrote: >

Hi Logan/All, I have added a check for the sg_dma_len == 0 : """ } __sgt_iter(struct scatterlist *sgl, bool dma) { struct sgt_iter s = { .sgp = sgl }; + if (sgl && sg_dma_len(sgl) == 0) + s.sgp = NULL; if (s.sgp) { ..... """ at location [1]. but it doens't fix the problem. You're right though, this

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 > with the