On 2019-01-29 12:32 p.m., Jason Gunthorpe wrote: > Jerome, I think it would be nice to have a helper scheme - I think the > simple case would be simple remapping of PCI BAR memory, so if we > could have, say something like: > > static const struct vm_operations_struct my_ops { > .p2p_map = p2p_ioremap_map_op, > .p2p_unmap = p2p_ioremap_unmap_op, > } > > struct ioremap_data { > [..] > } > > fops_mmap() { > vma->private_data = &driver_priv->ioremap_data; > return p2p_ioremap_device_memory(vma, exporting_device, [..]); > } This is roughly what I was expecting, except I don't see exactly what the p2p_map and p2p_unmap callbacks are for. The importing driver should see p2pdma/hmm struct pages and use the appropriate function to map them. It shouldn't be the responsibility of the exporting driver to implement the mapping. And I don't think we should have 'special' vma's for this (though we may need something to ensure we don't get mapping requests mixed with different types of pages...). I also figured there'd be a fault version of p2p_ioremap_device_memory() for when you are mapping P2P memory and you want to assign the pages lazily. Though, this can come later when someone wants to implement that. Logan
- Re: [RFC PATCH 3/5] mm/vma: add support for pee... Logan Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Christoph Hellwig
- Re: [RFC PATCH 3/5] mm/vma: add support for peer to peer... Jason Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for peer to... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for pee... Jason Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jason Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jason Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for peer to... Logan Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for pee... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for... Logan Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for... Logan Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for... Logan Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jason Gunthorpe
- Re: [RFC PATCH 3/5] mm/vma: add support for... Christoph Hellwig
- Re: [RFC PATCH 3/5] mm/vma: add support for... Jerome Glisse