Thanks Jason, I will resend it as a formal patch. Wendy > -----Original Message----- > From: Jason Wang [mailto:jasowang@xxxxxxxxxx] > Sent: Wednesday, December 07, 2016 7:18 PM > To: Jiaying Liang; ohad@xxxxxxxxxx; bjorn.andersson@xxxxxxxxxx; linux- > remoteproc@xxxxxxxxxxxxxxx; mst@xxxxxxxxxx; virtualization@lists.linux- > foundation.org > Cc: Jiaying Liang > Subject: Re: [RFC LINUX PATCH 0/2] Virtio ring works with DMA coherent > memory > > > > On 2016年12月07日 02:21, Wendy Liang wrote: > > RPMsg uses dma_alloc_coherent() to allocate memory to shared with the > remote. > > In this case, as there is no pages setup in the dma_alloc_coherent(), > > we cannot get the physical address back from the virtual address, and > > thus, we can set the sg_dma_addr to store the DMA address and mark it > > already DMA mapped. > > > > When virtio vring sees the sg_dma_addr is ready set, do not call > dma_map_page(). > > > > The issue was once discussed here: > > http://virtualization.linux-foundation.narkive.com/CfVP32Vy/rfc-0-4-rp > > msg-fix-init-of-dma-able-virtqueues > > > > Edgar E. Iglesias (1): > > rpmsg: DMA map sgs passed to virtio > > > > Wendy Liang (1): > > virtio_ring: Do not call dma_map_page if sg is already mapped. > > > > drivers/rpmsg/virtio_rpmsg_bus.c | 22 +++++++++++++++++++--- > > drivers/virtio/virtio_ring.c | 6 ++++++ > > 2 files changed, 25 insertions(+), 3 deletions(-) > > > > Looks good to me. > > I think you can send a formal patch (without RFC prefix). > > Thanks This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
