drm/vmwgfx: Optimize memory footprint for DMA buffers.

Use VRAM whenever there is free space for DMA buffers,
but use system GMR memory if using VRAM would cause an eviction.

This significantly reduces the guest system memory usage for
VMs with a large amount of VRAM allocated.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
index 37a81925b158469a45797a7fb7581a647a0aefbd..825ebe3d89d573c384dc3181e56b988e7bfeea55 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
@@ -48,6 +48,15 @@ struct ttm_placement vmw_vram_placement = {
        .busy_placement = &vram_placement_flags
 };
 
+struct ttm_placement vmw_vram_sys_placement = {
+       .fpfn = 0,
+       .lpfn = 0,
+       .num_placement = 1,
+       .placement = &vram_placement_flags,
+       .num_busy_placement = 1,
+       .busy_placement = &sys_placement_flags
+};
+
 struct ttm_placement vmw_vram_ne_placement = {
        .fpfn = 0,
        .lpfn = 0,

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 7532b9b47eecb80b2857edaa94fc31e0d410c954..50529a7f06fb6303f7127280c81821a7cb82cf5c 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -404,6 +404,7 @@ extern int vmw_mmap(struct file *filp, struct vm_area_struct *vma);
 
 extern struct ttm_placement vmw_vram_placement;
 extern struct ttm_placement vmw_vram_ne_placement;
+extern struct ttm_placement vmw_vram_sys_placement;
 extern struct ttm_placement vmw_sys_placement;
 extern struct ttm_bo_driver vmw_bo_driver;
 extern int vmw_dma_quiescent(struct drm_device *dev);

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 2e92da5674033cd1af7d1e658d8ac5fa9c5d0a0a..d69caf92ffe78bfc4060f7daf99c10d60af5e6b7 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -487,6 +487,21 @@ static int vmw_validate_single_buffer(struct vmw_private *dev_priv,
 {
        int ret;
 
+       if (vmw_dmabuf_gmr(bo) != SVGA_GMR_NULL)
+               return 0;
+
+       /**
+        * Put BO in VRAM, only if there is space.
+        */
+
+       ret = ttm_bo_validate(bo, &vmw_vram_sys_placement, true, false);
+       if (unlikely(ret == -ERESTARTSYS))
+               return ret;
+
+       /**
+        * Otherwise, set it up as GMR.
+        */
+
        if (vmw_dmabuf_gmr(bo) != SVGA_GMR_NULL)
                return 0;
 
@@ -494,6 +509,10 @@ static int vmw_validate_single_buffer(struct vmw_private *dev_priv,
        if (likely(ret == 0 || ret == -ERESTARTSYS))
                return ret;
 
+       /**
+        * If that failed, try VRAM again, this time evicting
+        * previous contents.
+        */
 
        ret = ttm_bo_validate(bo, &vmw_vram_placement, true, false);
        return ret;

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index e0878077e8aac0243c6f57dcab09d0ded01e8c3c..e01db120efff233679c9dc46eebb180c2de8b66e 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -872,7 +872,7 @@ int vmw_dmabuf_alloc_ioctl(struct drm_device *dev, void *data,
        }
 
        ret = vmw_dmabuf_init(dev_priv, &vmw_user_bo->dma, req->size,
-                             &vmw_vram_placement, true,
+                             &vmw_vram_sys_placement, true,
                              &vmw_user_dmabuf_destroy);
        if (unlikely(ret != 0))
                return ret;