>-----Original Message----- >From: dri-devel <dri-devel-boun...@lists.freedesktop.org> On Behalf Of >Gerd Hoffmann >Sent: Tuesday, December 10, 2019 3:58 AM >To: dri-devel@lists.freedesktop.org >Cc: David Airlie <airl...@linux.ie>; open list <linux-ker...@vger.kernel.org>; >open list:VIRTIO GPU DRIVER <virtualizat...@lists.linux-foundation.org>; >Gerd Hoffmann <kra...@redhat.com>; gurchetansi...@chromium.org >Subject: [PATCH] drm/virtio: fix mmap page attributes > >virtio-gpu uses cached mappings. shmem helpers use writecombine though. >So roll our own mmap function, wrapping drm_gem_shmem_mmap(), to >tweak >vm_page_prot accordingly. > >Reported-by: Gurchetan Singh <gurchetansi...@chromium.org> >Signed-off-by: Gerd Hoffmann <kra...@redhat.com> >--- > drivers/gpu/drm/virtio/virtgpu_object.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > >diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c >b/drivers/gpu/drm/virtio/virtgpu_object.c >index 017a9e0fc3bb..158610902054 100644 >--- a/drivers/gpu/drm/virtio/virtgpu_object.c >+++ b/drivers/gpu/drm/virtio/virtgpu_object.c >@@ -75,6 +75,22 @@ static void virtio_gpu_free_object(struct >drm_gem_object *obj) > drm_gem_shmem_free_object(obj); > } > >+static int virtio_gpu_gem_mmap(struct drm_gem_object *obj, struct >vm_area_struct *vma) >+{ >+ pgprot_t prot; >+ int ret; >+ >+ ret = drm_gem_shmem_mmap(obj, vma); >+ if (ret < 0) >+ return ret; >+ >+ /* virtio-gpu needs normal caching, so clear writecombine */
A minor nit. I was looking at this code, trying to see where you were clearing the writecombine bit. Maybe a more clear comment would be: virtio-gpu needs normal caching, re-do protection without writecombine ? Mike >+ prot = vm_get_page_prot(vma->vm_flags); >+ prot = pgprot_decrypted(prot); >+ vma->vm_page_prot = prot; >+ return 0; >+} >+ > static const struct drm_gem_object_funcs virtio_gpu_gem_funcs = { > .free = virtio_gpu_free_object, > .open = virtio_gpu_gem_object_open, >@@ -86,7 +102,7 @@ static const struct drm_gem_object_funcs >virtio_gpu_gem_funcs = { > .get_sg_table = drm_gem_shmem_get_sg_table, > .vmap = drm_gem_shmem_vmap, > .vunmap = drm_gem_shmem_vunmap, >- .mmap = &drm_gem_shmem_mmap, >+ .mmap = &virtio_gpu_gem_mmap, > }; > > struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev, >-- >2.18.1 > >_______________________________________________ >dri-devel mailing list >dri-devel@lists.freedesktop.org >https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel