i915/gvt: Save the initial HW state snapshot in i915

Save the initial HW state snapshot in i915 so that the rest code of GVT-g
can be moved into a dedicated module while it can still get a clean
initial HW state saved at the correct time during the initialization of
i915. The futhrer vGPU created by GVT-g will use this HW state as the
initial HW state.

v6:
- Remove the reference of intel_gvt_device_info.(Christoph)
- Refine the save_mmio() function. (Christoph)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Vivi Rodrigo <rodrigo.vivi@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220407071945.72148-3-zhi.a.wang@intel.com

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index fa14da8..0830020 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -432,6 +432,8 @@ struct i915_virtual_gpu {
        struct mutex lock; /* serialises sending of g2v_notify command pkts */
        bool active;
        u32 caps;
+       u32 *initial_mmio;
+       u8 *initial_cfg_space;
 };
 
 struct i915_selftest_stash {

diff --git a/drivers/gpu/drm/i915/intel_gvt.c b/drivers/gpu/drm/i915/intel_gvt.c
index cf6e989..65daab2 100644 (file)
--- a/drivers/gpu/drm/i915/intel_gvt.c
+++ b/drivers/gpu/drm/i915/intel_gvt.c
@@ -86,6 +86,85 @@ bail:
        dev_priv->params.enable_gvt = 0;
 }
 
+static void free_initial_hw_state(struct drm_i915_private *dev_priv)
+{
+       struct i915_virtual_gpu *vgpu = &dev_priv->vgpu;
+
+       vfree(vgpu->initial_mmio);
+       vgpu->initial_mmio = NULL;
+
+       kfree(vgpu->initial_cfg_space);
+       vgpu->initial_cfg_space = NULL;
+}
+
+static void save_mmio(struct intel_gvt_mmio_table_iter *iter, u32 offset,
+                     u32 size)
+{
+       struct drm_i915_private *dev_priv = iter->i915;
+       u32 *mmio, i;
+
+       for (i = offset; i < offset + size; i += 4) {
+               mmio = iter->data + i;
+               *mmio = intel_uncore_read_notrace(to_gt(dev_priv)->uncore,
+                                                 _MMIO(i));
+       }
+}
+
+static int handle_mmio(struct intel_gvt_mmio_table_iter *iter,
+                      u32 offset, u32 size)
+{
+       if (WARN_ON(!IS_ALIGNED(offset, 4)))
+               return -EINVAL;
+
+       save_mmio(iter, offset, size);
+       return 0;
+}
+
+static int save_initial_hw_state(struct drm_i915_private *dev_priv)
+{
+       struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
+       struct i915_virtual_gpu *vgpu = &dev_priv->vgpu;
+       struct intel_gvt_mmio_table_iter iter;
+       void *mem;
+       int i, ret;
+
+       mem = kzalloc(PCI_CFG_SPACE_EXP_SIZE, GFP_KERNEL);
+       if (!mem)
+               return -ENOMEM;
+
+       vgpu->initial_cfg_space = mem;
+
+       for (i = 0; i < PCI_CFG_SPACE_EXP_SIZE; i += 4)
+               pci_read_config_dword(pdev, i, mem + i);
+
+       mem = vzalloc(2 * SZ_1M);
+       if (!mem) {
+               ret = -ENOMEM;
+               goto err_mmio;
+       }
+
+       vgpu->initial_mmio = mem;
+
+       iter.i915 = dev_priv;
+       iter.data = vgpu->initial_mmio;
+       iter.handle_mmio_cb = handle_mmio;
+
+       ret = intel_gvt_iterate_mmio_table(&iter);
+       if (ret)
+               goto err_iterate;
+
+       return 0;
+
+err_iterate:
+       vfree(vgpu->initial_mmio);
+       vgpu->initial_mmio = NULL;
+err_mmio:
+       kfree(vgpu->initial_cfg_space);
+       vgpu->initial_cfg_space = NULL;
+
+       return ret;
+}
+
 /**
  * intel_gvt_init - initialize GVT components
  * @dev_priv: drm i915 private data
@@ -115,15 +194,23 @@ int intel_gvt_init(struct drm_i915_private *dev_priv)
                return -EIO;
        }
 
+       ret = save_initial_hw_state(dev_priv);
+       if (ret) {
+               drm_dbg(&dev_priv->drm, "Fail to save initial HW state\n");
+               goto err_save_hw_state;
+       }
+
        ret = intel_gvt_init_device(dev_priv);
        if (ret) {
                drm_dbg(&dev_priv->drm, "Fail to init GVT device\n");
-               goto bail;
+               goto err_init_device;
        }
 
        return 0;
 
-bail:
+err_init_device:
+       free_initial_hw_state(dev_priv);
+err_save_hw_state:
        dev_priv->params.enable_gvt = 0;
        return 0;
 }
@@ -147,6 +234,7 @@ void intel_gvt_driver_remove(struct drm_i915_private *dev_priv)
                return;
 
        intel_gvt_clean_device(dev_priv);
+       free_initial_hw_state(dev_priv);
 }
 
 /**