drm/i915: Detect virtual south bridge
Virtualized systems often use a virtual P2X4 south bridge.
Detect this in intel_detect_pch and make a best guess as to which PCH
we should be using.
This was seen on vmware esxi hypervisor. When passing the graphics device
through to a guest, it can not pass through the PCH. Instead it simulates
a P2X4 southbridge.
Signed-off-by: Robert Beckett <robert.beckett@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e6d7a69..b31485a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -443,6 +443,34 @@
MODULE_DEVICE_TABLE(pci, pciidlist);
+static enum intel_pch intel_virt_detect_pch(struct drm_device *dev)
+{
+ enum intel_pch ret = PCH_NOP;
+
+ /*
+ * In a virtualized passthrough environment we can be in a
+ * setup where the ISA bridge is not able to be passed through.
+ * In this case, a south bridge can be emulated and we have to
+ * make an educated guess as to which PCH is really there.
+ */
+
+ if (IS_GEN5(dev)) {
+ ret = PCH_IBX;
+ DRM_DEBUG_KMS("Assuming Ibex Peak PCH\n");
+ } else if (IS_GEN6(dev) || IS_IVYBRIDGE(dev)) {
+ ret = PCH_CPT;
+ DRM_DEBUG_KMS("Assuming CouarPoint PCH\n");
+ } else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
+ ret = PCH_LPT;
+ DRM_DEBUG_KMS("Assuming LynxPoint PCH\n");
+ } else if (IS_SKYLAKE(dev)) {
+ ret = PCH_SPT;
+ DRM_DEBUG_KMS("Assuming SunrisePoint PCH\n");
+ }
+
+ return ret;
+}
+
void intel_detect_pch(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -503,6 +531,8 @@
dev_priv->pch_type = PCH_SPT;
DRM_DEBUG_KMS("Found SunrisePoint LP PCH\n");
WARN_ON(!IS_SKYLAKE(dev));
+ } else if (id == INTEL_PCH_P2X_DEVICE_ID_TYPE) {
+ dev_priv->pch_type = intel_virt_detect_pch(dev);
} else
continue;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7d83f67..04d710f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2608,6 +2608,7 @@
#define INTEL_PCH_LPT_LP_DEVICE_ID_TYPE 0x9c00
#define INTEL_PCH_SPT_DEVICE_ID_TYPE 0xA100
#define INTEL_PCH_SPT_LP_DEVICE_ID_TYPE 0x9D00
+#define INTEL_PCH_P2X_DEVICE_ID_TYPE 0x7100
#define INTEL_PCH_TYPE(dev) (__I915__(dev)->pch_type)
#define HAS_PCH_SPT(dev) (INTEL_PCH_TYPE(dev) == PCH_SPT)