[PATCH v1 08/12] drm/i915/gvt: GVTg handle guest shared_page setup

[Xiaolin Zhang]

GVTg implemented guest shared_page register operation and read and write
shared_page functionality based on hypervisor read and write functionality.

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      |  9 ++++++--
 drivers/gpu/drm/i915/gvt/handlers.c | 20 +++++++++++++++++
 drivers/gpu/drm/i915/gvt/vgpu.c     | 43 +++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 31d8a2bcc..d635313 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -214,6 +214,8 @@ struct intel_vgpu {
 
 	u32 scan_nonprivbb;
 	u32 pv_caps;
+	u64 shared_page_gpa;
+	bool shared_page_enabled;
 };
 
 static inline void *intel_vgpu_vdev(struct intel_vgpu *vgpu)
@@ -536,7 +538,7 @@ static inline u64 intel_vgpu_get_bar_gpa(struct intel_vgpu *vgpu, int bar)
 static inline bool intel_vgpu_enabled_pv_cap(struct intel_vgpu *vgpu,
 		enum pv_caps cap)
 {
-	return (vgpu->pv_caps & cap);
+	return vgpu->shared_page_enabled && (vgpu->pv_caps & cap);
 }
 
 void intel_vgpu_clean_opregion(struct intel_vgpu *vgpu);
@@ -692,7 +694,10 @@ void intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu);
 void intel_gvt_debugfs_remove_vgpu(struct intel_vgpu *vgpu);
 void 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);
+int intel_gvt_write_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 bfea065..295e43a 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1204,6 +1204,8 @@ 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;
@@ -1221,6 +1223,9 @@ static int handle_g2v_notification(struct intel_vgpu *vgpu, int notification)
 	enum intel_gvt_gtt_type root_entry_type = GTT_TYPE_PPGTT_ROOT_L4_ENTRY;
 	struct intel_vgpu_mm *mm;
 	u64 *pdps;
+	unsigned long gpa, gfn;
+	u16 ver_major = PV_MAJOR;
+	u16 ver_minor = PV_MINOR;
 
 	pdps = (u64 *)&vgpu_vreg64_t(vgpu, vgtif_reg(pdp[0]));
 
@@ -1234,6 +1239,19 @@ 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_REGISTER:
+		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;
+
+		intel_gvt_write_shared_page(vgpu, 0, &ver_major, 2);
+		intel_gvt_write_shared_page(vgpu, 2, &ver_minor, 2);
+		break;
 	case VGT_G2V_EXECLIST_CONTEXT_CREATE:
 	case VGT_G2V_EXECLIST_CONTEXT_DESTROY:
 	case 1:	/* Remove this in guest driver. */
@@ -1290,6 +1308,8 @@ 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]):
 		invalid_write = true;
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 4867426..e9bc683 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -64,6 +64,8 @@ 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));
@@ -609,3 +611,44 @@ 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 >= PAGE_SIZE)
+		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;
+}
+
+int intel_gvt_write_shared_page(struct intel_vgpu *vgpu,
+		unsigned int offset, void *buf, unsigned long len)
+{
+	int ret = -EINVAL;
+	unsigned long gpa;
+
+	if (offset >= PAGE_SIZE)
+		goto err;
+
+	gpa = vgpu->shared_page_gpa + offset;
+	ret = intel_gvt_hypervisor_write_gpa(vgpu, gpa, buf, len);
+	if (!ret)
+		return ret;
+err:
+	gvt_vgpu_err("write shared page (offset %x) failed", offset);
+	memset(buf, 0, len);
+	return ret;
+}
-- 
2.7.4