Displaying 7 results from an estimated 7 matches for "dma_xmb".
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dma_wmb
2018 Jun 07
2
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
...y to make them happy.
> b) coherency
>
> On many architectures DMA is not cache coherent, and we need
> to invalidate and/or write back cache lines before doing
> DMA. Again, I wonder how this is every going to work with
> hardware based virtio implementations.
You mean dma_Xmb and friends?
There's a new feature VIRTIO_F_IO_BARRIER that's being proposed
for that.
> Even worse I think this
> is actually broken at least for VIVT event for virtualized
> implementations. E.g. a KVM guest is going to access memory
> using different virtual addresses...
2018 Jun 07
2
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
...y to make them happy.
> b) coherency
>
> On many architectures DMA is not cache coherent, and we need
> to invalidate and/or write back cache lines before doing
> DMA. Again, I wonder how this is every going to work with
> hardware based virtio implementations.
You mean dma_Xmb and friends?
There's a new feature VIRTIO_F_IO_BARRIER that's being proposed
for that.
> Even worse I think this
> is actually broken at least for VIVT event for virtualized
> implementations. E.g. a KVM guest is going to access memory
> using different virtual addresses...
2018 May 31
7
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
On Thu, May 31, 2018 at 09:09:24AM +0530, Anshuman Khandual wrote:
> On 05/24/2018 12:51 PM, Ram Pai wrote:
> > On Wed, May 23, 2018 at 09:50:02PM +0300, Michael S. Tsirkin wrote:
> >> subj: s/virito/virtio/
> >>
> > ..snip..
> >>> machine_subsys_initcall_sync(pseries, tce_iommu_bus_notifier_init);
> >>> +
> >>> +bool
2018 May 31
7
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
On Thu, May 31, 2018 at 09:09:24AM +0530, Anshuman Khandual wrote:
> On 05/24/2018 12:51 PM, Ram Pai wrote:
> > On Wed, May 23, 2018 at 09:50:02PM +0300, Michael S. Tsirkin wrote:
> >> subj: s/virito/virtio/
> >>
> > ..snip..
> >>> machine_subsys_initcall_sync(pseries, tce_iommu_bus_notifier_init);
> >>> +
> >>> +bool
2018 Jun 08
0
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
...cy
> >
> > On many architectures DMA is not cache coherent, and we need
> > to invalidate and/or write back cache lines before doing
> > DMA. Again, I wonder how this is every going to work with
> > hardware based virtio implementations.
>
>
> You mean dma_Xmb and friends?
> There's a new feature VIRTIO_F_IO_BARRIER that's being proposed
> for that.
No. I mean the fact that PCI(e) devices often are not coherent with
the cache. So you need to writeback the cpu cache before transferring
data to the device, and invalidate the cpu cache befo...
2018 Jun 11
0
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
...ny architectures DMA is not cache coherent, and we need
> > > to invalidate and/or write back cache lines before doing
> > > DMA. Again, I wonder how this is every going to work with
> > > hardware based virtio implementations.
> >
> >
> > You mean dma_Xmb and friends?
> > There's a new feature VIRTIO_F_IO_BARRIER that's being proposed
> > for that.
> >
> >
> > > Even worse I think this
> > > is actually broken at least for VIVT event for virtualized
> > > implementations. E.g. a KVM gu...
2018 Jun 11
1
[RFC V2] virtio: Add platform specific DMA API translation for virito devices
...che coherent, and we need
> > > > to invalidate and/or write back cache lines before doing
> > > > DMA. Again, I wonder how this is every going to work with
> > > > hardware based virtio implementations.
> > >
> > >
> > > You mean dma_Xmb and friends?
> > > There's a new feature VIRTIO_F_IO_BARRIER that's being proposed
> > > for that.
> > >
> > >
> > > > Even worse I think this
> > > > is actually broken at least for VIVT event for virtualized
> > > &g...