drm/i915/gvt: Fix mmap range check

This is to fix missed mmap range check on vGPU bar2 region
and only allow to map vGPU allocated GMADDR range, which means
user space should support sparse mmap to get proper offset for
mmap vGPU aperture. And this takes care of actual pgoff in mmap
request as original code always does from beginning of vGPU
aperture.

Fixes: b5a3643943c1 ("drm/i915/gvt/kvmgt: add vfio/mdev support to KVMGT")
Cc: "Monroy, Rodrigo Axel" <rodrigo.axel.monroy@intel.com>
Cc: "Orrala Contreras, Alfredo" <alfredo.orrala.contreras@intel.com>
Cc: stable@vger.kernel.org # v4.10+
Reviewed-by: Hang Yuan <hang.yuan@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index a3ee6b7c3cfc4a34e025fbd6a1ec45e120672605..dd3dfd00f4e60088e350a22a061cf0ba4eb0dfc8 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -996,7 +996,7 @@ static int intel_vgpu_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
 {
        unsigned int index;
        u64 virtaddr;
-       unsigned long req_size, pgoff = 0;
+       unsigned long req_size, pgoff, req_start;
        pgprot_t pg_prot;
        struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
 
@@ -1014,7 +1014,17 @@ static int intel_vgpu_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
        pg_prot = vma->vm_page_prot;
        virtaddr = vma->vm_start;
        req_size = vma->vm_end - vma->vm_start;
-       pgoff = vgpu_aperture_pa_base(vgpu) >> PAGE_SHIFT;
+       pgoff = vma->vm_pgoff &
+               ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
+       req_start = pgoff << PAGE_SHIFT;
+
+       if (!intel_vgpu_in_aperture(vgpu, req_start))
+               return -EINVAL;
+       if (req_start + req_size >
+           vgpu_aperture_offset(vgpu) + vgpu_aperture_sz(vgpu))
+               return -EINVAL;
+
+       pgoff = (gvt_aperture_pa_base(vgpu->gvt) >> PAGE_SHIFT) + pgoff;
 
        return remap_pfn_range(vma, virtaddr, pgoff, req_size, pg_prot);
 }