[PATCH v2] drm/i915/gvt: enter failsafe mode when guest requires more resources

[Min He]

Windows guest will notitfy GVT-g to request more resources through g2v
interface, when its resources are not enough.
This patch is to handle this case and let vgpu enter failsafe mode to
avoid too many error messages.

Signed-off-by: Min He <min.he at intel.com>
Signed-off-by: Pei Zhang <pei.zhang at intel.com>
---
 drivers/gpu/drm/i915/gvt/handlers.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index 03f52a1..51c1c57 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -152,6 +152,7 @@ static int render_mmio_to_ring_id(struct intel_gvt *gvt, unsigned int reg)
 
 enum {
 	UNSUPPORTED_GUESTS,
+	INSUFFICIENT_RESOURCE,
 } FAILSAFE_REASON;
 
 static void enter_failsafe_mode(struct intel_vgpu *vgpu, int reason)
@@ -161,6 +162,9 @@ static void enter_failsafe_mode(struct intel_vgpu *vgpu, int reason)
 		pr_err("***Detected guest not supporting GVT-g***\n");
 		pr_err("***Please update your guest driver*******\n");
 		break;
+	case INSUFFICIENT_RESOURCE:
+		pr_err("***Guest requests more resource**********\n");
+		pr_err("***Please try another VGPU type**********\n");
 	default:
 		break;
 	}
@@ -1105,6 +1109,9 @@ static int pvinfo_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 	case _vgtif_reg(execlist_context_descriptor_lo):
 	case _vgtif_reg(execlist_context_descriptor_hi):
 		break;
+	case _vgtif_reg(rsv5[0])..._vgtif_reg(rsv5[4]):
+		enter_failsafe_mode(vgpu, INSUFFICIENT_RESOURCE);
+		break;
 	default:
 		gvt_err("invalid pvinfo write offset %x bytes %x data %x\n",
 				offset, bytes, data);
-- 
1.9.1