[Intel-gfx] [PATCH v4 6/8] drm/i915/gvt: GVTg handle shared_page setup

[Xiaolin Zhang]

GVTg implemented shared_page setup operation and read_shared_page
functionality based on hypervisor_read_gpa().

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

v0: RFC
v1: rebase
v2: rebase
v3: added shared_page_gpa check and if read_gpa failure, return zero
memory and handle VGT_G2V_SHARED_PAGE_SETUP g2v notification
v4: rebase

Signed-off-by: Xiaolin Zhang <xiaolin.zhang at intel.com>
---
 drivers/gpu/drm/i915/gvt/gvt.h      |  6 +++++-
 drivers/gpu/drm/i915/gvt/handlers.c | 15 +++++++++++++++
 drivers/gpu/drm/i915/gvt/vgpu.c     | 24 ++++++++++++++++++++++++
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index a4fd979..b01a54f 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -49,6 +49,7 @@
 #include "fb_decoder.h"
 #include "dmabuf.h"
 #include "page_track.h"
+#include "i915_vgpu.h"
 
 #define GVT_MAX_VGPU 8
 
@@ -229,6 +230,8 @@ struct intel_vgpu {
 	struct completion vblank_done;
 
 	u32 scan_nonprivbb;
+	u64 shared_page_gpa;
+	bool shared_page_enabled;
 };
 
 /* validating GM healthy status*/
@@ -686,7 +689,8 @@ int intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu);
 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);
-
+int 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 0333652..28b390c 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1168,6 +1168,8 @@ static int pvinfo_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
 	case 0x78010:	/* vgt_caps */
 	case 0x7881c:
 	case _vgtif_reg(pv_caps):
+	case _vgtif_reg(shared_page_gpa):
+	case _vgtif_reg(shared_page_gpa) + 4:
 		break;
 	default:
 		invalid_read = true;
@@ -1185,6 +1187,7 @@ static int handle_g2v_notification(struct intel_vgpu *vgpu, int notification)
 	intel_gvt_gtt_type_t root_entry_type = GTT_TYPE_PPGTT_ROOT_L4_ENTRY;
 	struct intel_vgpu_mm *mm;
 	u64 *pdps;
+	unsigned long gpa, gfn;
 
 	pdps = (u64 *)&vgpu_vreg64_t(vgpu, vgtif_reg(pdp[0]));
 
@@ -1198,6 +1201,16 @@ static int handle_g2v_notification(struct intel_vgpu *vgpu, int notification)
 	case VGT_G2V_PPGTT_L3_PAGE_TABLE_DESTROY:
 	case VGT_G2V_PPGTT_L4_PAGE_TABLE_DESTROY:
 		return intel_vgpu_put_ppgtt_mm(vgpu, pdps);
+	case VGT_G2V_SHARED_PAGE_SETUP:
+		gpa = vgpu_vreg64_t(vgpu, vgtif_reg(shared_page_gpa));
+		gfn = gpa >> PAGE_SHIFT;
+		if (!intel_gvt_hypervisor_is_valid_gfn(vgpu, gfn)) {
+			vgpu_vreg_t(vgpu, vgtif_reg(pv_caps)) = 0;
+			return 0;
+		}
+		vgpu->shared_page_gpa = gpa;
+		vgpu->shared_page_enabled = true;
+		break;
 	case VGT_G2V_EXECLIST_CONTEXT_CREATE:
 	case VGT_G2V_EXECLIST_CONTEXT_DESTROY:
 	case 1:	/* Remove this in guest driver. */
@@ -1257,6 +1270,8 @@ static int pvinfo_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 	case _vgtif_reg(pdp[3].hi):
 	case _vgtif_reg(execlist_context_descriptor_lo):
 	case _vgtif_reg(execlist_context_descriptor_hi):
+	case _vgtif_reg(shared_page_gpa):
+	case _vgtif_reg(shared_page_gpa) + 4:
 		break;
 	case _vgtif_reg(rsv5[0])..._vgtif_reg(rsv5[3]):
 		enter_failsafe_mode(vgpu, GVT_FAILSAFE_INSUFFICIENT_RESOURCE);
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 9c9a192..4d241a7 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -63,6 +63,8 @@ void populate_pvinfo_page(struct intel_vgpu *vgpu)
 	vgpu_vreg_t(vgpu, vgtif_reg(cursor_x_hot)) = UINT_MAX;
 	vgpu_vreg_t(vgpu, vgtif_reg(cursor_y_hot)) = UINT_MAX;
 
+	vgpu_vreg64_t(vgpu, vgtif_reg(shared_page_gpa)) = 0;
+
 	gvt_dbg_core("Populate PVINFO PAGE for vGPU %d\n", vgpu->id);
 	gvt_dbg_core("aperture base [GMADR] 0x%llx size 0x%llx\n",
 		vgpu_aperture_gmadr_base(vgpu), vgpu_aperture_sz(vgpu));
@@ -593,3 +595,25 @@ 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
+ */
+int intel_gvt_read_shared_page(struct intel_vgpu *vgpu,
+		unsigned int offset, void *buf, unsigned long len)
+{
+	int ret = -EINVAL;
+	unsigned long gpa;
+
+	if (offset >= sizeof(struct gvt_shared_page))
+		goto err;
+
+	gpa = vgpu->shared_page_gpa + offset;
+	ret = intel_gvt_hypervisor_read_gpa(vgpu, gpa, buf, len);
+	if (!ret)
+		return ret;
+err:
+	gvt_vgpu_err("read shared page (offset %x) failed", offset);
+	memset(buf, 0, len);
+	return ret;
+}
-- 
2.7.4