[RFC PATCH kernel 4/5] vfio_pci: Allow mapping extra regions

[Alexey Kardashevskiy]

Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
 drivers/vfio/pci/vfio_pci_private.h |  3 +++
 drivers/vfio/pci/vfio_pci.c         | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

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 3729937..7bddf1e 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1123,10 +1123,16 @@ 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])
-               return -EINVAL;
 
        phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
        req_len = vma->vm_end - vma->vm_start;
-- 
2.11.0