On Mon, Oct 15, 2018 at 08:42:31PM +1100, Alexey Kardashevskiy wrote: 65;5402;1c> So far we only allowed mapping of MMIO BARs to the userspace. However > there there are GPUs with on-board coherent RAM accessible via side > channels which we also want to map to the userspace. The first client > for this is NVIDIA V100 GPU with NVLink2 direct links to a POWER9 > NPU-enabled CPU; such GPUs have 16GB RAM which is coherently mapped > to the system address space, we are going to export these as an extra > PCI region. > > We already support extra PCI regions and this adds support for mapping > them to the userspace. > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> > --- > Changes: > v2: > * reverted one of mistakenly removed error checks > --- > drivers/vfio/pci/vfio_pci_private.h | 3 +++ > drivers/vfio/pci/vfio_pci.c | 8 ++++++++ > 2 files changed, 11 insertions(+) > > diff --git a/drivers/vfio/pci/vfio_pci_private.h > b/drivers/vfio/pci/vfio_pci_private.h > index cde3b5d..86aab05 100644 > --- a/drivers/vfio/pci/vfio_pci_private.h > +++ b/drivers/vfio/pci/vfio_pci_private.h > @@ -59,6 +59,9 @@ struct vfio_pci_regops { > size_t count, loff_t *ppos, bool iswrite); > void (*release)(struct vfio_pci_device *vdev, > struct vfio_pci_region *region); > + int (*mmap)(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vm_area_struct *vma); > }; > > struct vfio_pci_region { > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index d9af440..7923314 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -1126,6 +1126,14 @@ static int vfio_pci_mmap(void *device_data, struct > vm_area_struct *vma) > return -EINVAL; > if ((vma->vm_flags & VM_SHARED) == 0) > return -EINVAL; > + if (index >= VFIO_PCI_NUM_REGIONS) { > + int regnum = index - VFIO_PCI_NUM_REGIONS; > + struct vfio_pci_region *region = vdev->region + regnum; > + > + if (region && region->ops && region->ops->mmap) > + return region->ops->mmap(vdev, region, vma); > + return -EINVAL; > + } > if (index >= VFIO_PCI_ROM_REGION_INDEX) > return -EINVAL; > if (!vdev->bar_mmap_supported[index]) -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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