Re: [PATCH 3/3] virtio_pci: Use the DMA API

2015-10-27 Thread Joerg Roedel
On Wed, Oct 28, 2015 at 11:22:52AM +0900, David Woodhouse wrote: > On Wed, 2015-10-28 at 11:15 +0900, Joerg Roedel wrote: > > I think a good test for that is to boot a virtio kvm-guest with > > swiotlb=force and see if it still works. > > That's useful but doesn't cover the cases where dma_wmb() i

Re: [PATCH 3/3] virtio_pci: Use the DMA API

2015-10-27 Thread Joerg Roedel
On Wed, Oct 28, 2015 at 11:15:30AM +0900, Joerg Roedel wrote: > Same here, you need to call the dma_sync* functions when passing data > from/to the virtio-device. Okay, forget about this comment. This patch only converts to dma_coherent allocations, which don't need synchronization. > I think a g

Re: [PATCH 3/3] virtio_pci: Use the DMA API

2015-10-27 Thread David Woodhouse
On Wed, 2015-10-28 at 11:15 +0900, Joerg Roedel wrote: > On Tue, Oct 27, 2015 at 06:17:10PM -0700, Andy Lutomirski wrote: > > From: Andy Lutomirski > > > > This fixes virtio-pci on platforms and busses that have IOMMUs. > > This > > will break the experimental QEMU Q35 IOMMU support until QEMU

Re: [PATCH 3/3] virtio_pci: Use the DMA API

2015-10-27 Thread Joerg Roedel
On Tue, Oct 27, 2015 at 06:17:10PM -0700, Andy Lutomirski wrote: > From: Andy Lutomirski > > This fixes virtio-pci on platforms and busses that have IOMMUs. This > will break the experimental QEMU Q35 IOMMU support until QEMU is > fixed. In exchange, it fixes physical virtio hardware as well as