From a15b1883fee11e07e5db7f003a863cc419647e79 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 19 Dec 2018 19:52:30 +1100 Subject: [PATCH] vfio_pci: Allow mapping extra regions So far we only allowed mapping of MMIO BARs to the userspace. However 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 Reviewed-by: David Gibson Acked-by: Alex Williamson Signed-off-by: Michael Ellerman --- drivers/vfio/pci/vfio_pci.c | 9 +++++++++ drivers/vfio/pci/vfio_pci_private.h | 3 +++ 2 files changed, 12 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 50cdedfca9fe..9a86470f4ed9 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1117,6 +1117,15 @@ 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 && + (region->flags & VFIO_REGION_INFO_FLAG_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]) diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index cde3b5d3441a..86aab05d3d46 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 { -- 2.30.2