drm/i915/gvt: introduce intel_vgpu_reset_cfg_space to reset configuration space

This patch introduces a new function intel_vgpu_reset_cfg_space()
to reset vGPU configuration space. This function will unmap gttmmio
and aperture if they are mapped before. Then entire cfg space will
be restored to default values.

Currently we only do such reset when vGPU is not owned by any VM
so we simply restore entire cfg space to default value, not following
the PCIe FLR spec that some fields should remain unchanged.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/cfg_space.c b/drivers/gpu/drm/i915/gvt/cfg_space.c
index 82f449d59884d2e20e3c922bb334f9d0ec25cd73..4a6a2ed65732e1fde39457148165274deda52db6 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/cfg_space.c
+++ b/drivers/gpu/drm/i915/gvt/cfg_space.c
@@ -331,3 +331,28 @@ void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
                vgpu->cfg_space.bar[i].tracked = false;
        }
 }
+
+/**
+ * intel_vgpu_reset_cfg_space - reset vGPU configuration space
+ *
+ * @vgpu: a vGPU
+ *
+ */
+void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu)
+{
+       u8 cmd = vgpu_cfg_space(vgpu)[PCI_COMMAND];
+       bool primary = vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] !=
+                               INTEL_GVT_PCI_CLASS_VGA_OTHER;
+
+       if (cmd & PCI_COMMAND_MEMORY) {
+               trap_gttmmio(vgpu, false);
+               map_aperture(vgpu, false);
+       }
+
+       /**
+        * Currently we only do such reset when vGPU is not
+        * owned by any VM, so we simply restore entire cfg
+        * space to default value.
+        */
+       intel_vgpu_init_cfg_space(vgpu, primary);
+}

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index ab505552d313691fcffe522b2228c3a32a3046f7..9c97d7d3644901d259e0828634d9dda60340a81c 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -414,6 +414,8 @@ int intel_gvt_ggtt_h2g_index(struct intel_vgpu *vgpu, unsigned long h_index,
 
 void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
                bool primary);
+void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu);
+
 int intel_vgpu_emulate_cfg_read(struct intel_vgpu *vgpu, unsigned int offset,
                void *p_data, unsigned int bytes);