[Intel-gfx] [RFC 07/10] drm/i915/gvt: GVTg read_shared_page implementation

[Xiaolin Zhang]

GVTg implemented the read_shared_page functionality based on
hypervisor_read_gpa().

the shared_page_gpa was passed from guest driver through PVINFO
shared_page_gpa register.

Signed-off-by: Xiaolin Zhang <xiaolin.zhang at intel.com>
---
 drivers/gpu/drm/i915/gvt/gvt.h      |  4 +++-
 drivers/gpu/drm/i915/gvt/handlers.c |  5 +++++
 drivers/gpu/drm/i915/gvt/vgpu.c     | 14 ++++++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 31f6cdb..7562f75 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -232,6 +232,7 @@ struct intel_vgpu {
 	struct completion vblank_done;
 
 	u32 scan_nonprivbb;
+	u64 shared_page_gpa;
 };
 
 /* validating GM healthy status*/
@@ -690,7 +691,8 @@ static inline void intel_gvt_mmio_set_in_ctx(
 void intel_gvt_debugfs_remove_vgpu(struct intel_vgpu *vgpu);
 int intel_gvt_debugfs_init(struct intel_gvt *gvt);
 void intel_gvt_debugfs_clean(struct intel_gvt *gvt);
-
+void intel_gvt_read_shared_page(struct intel_vgpu *vgpu,
+		unsigned int offset, void *buf, unsigned long len);
 
 #include "trace.h"
 #include "mpt.h"
diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index 36171e6..a229770 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1251,6 +1251,11 @@ static int pvinfo_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 			vgpu_vreg(vgpu, offset) = 0;
 		}
 		break;
+	case _vgtif_reg(shared_page_gpa.lo):
+	case _vgtif_reg(shared_page_gpa.hi):
+		vgpu->shared_page_gpa = vgpu_vreg64_t(vgpu,
+				vgtif_reg(shared_page_gpa));
+		break;
 	/* add xhot and yhot to handled list to avoid error log */
 	case _vgtif_reg(cursor_x_hot):
 	case _vgtif_reg(cursor_y_hot):
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 1aed197..7101e45 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -589,3 +589,17 @@ void intel_gvt_reset_vgpu(struct intel_vgpu *vgpu)
 	intel_gvt_reset_vgpu_locked(vgpu, true, 0);
 	mutex_unlock(&vgpu->vgpu_lock);
 }
+
+/**
+ * intel_gvt_read_shared_page - read content from shared page
+ */
+void intel_gvt_read_shared_page(struct intel_vgpu *vgpu,
+		unsigned int offset, void *buf, unsigned long len)
+{
+	int ret = 0;
+	unsigned long gpa = vgpu->shared_page_gpa + offset;
+
+	ret = intel_gvt_hypervisor_read_gpa(vgpu, gpa, buf, len);
+	if (ret)
+		gvt_vgpu_err("read shared page (offset %x) failed", offset);
+}
-- 
1.8.3.1