The engine provides a mirror of the CSB and CSB write pointer in the HWSP.
Read these status from virtual HWSP in VM can reduce CPU utilization while
applications have much more short GPU workloads. Here we update the
corresponding data in virtual HWSP as it in virtual MMIO.
Before read these status from HWSP in GVT-g VM, please ensure the host
support it by checking the BIT(3) of caps in PVINFO.
Virtual HWSP only support GEN8+ platform, since the HWSP MMIO may change
follow the platform update, please add the corresponding MMIO emulation
when enable new platforms in GVT-g.
Signed-off-by: Weinan Li <weinan.z.li@xxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/execlist.c | 16 ++++++++++++++
drivers/gpu/drm/i915/gvt/gvt.h | 1 +
drivers/gpu/drm/i915/gvt/handlers.c | 42 +++++++++++++++++++++++++++++++++++--
drivers/gpu/drm/i915/gvt/vgpu.c | 8 +++++++
drivers/gpu/drm/i915/i915_pvinfo.h | 1 +
5 files changed, 66 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gvt/execlist.c b/drivers/gpu/drm/i915/gvt/execlist.c
index 5c966ed..b0c7e9e 100644
--- a/drivers/gpu/drm/i915/gvt/execlist.c
+++ b/drivers/gpu/drm/i915/gvt/execlist.c
@@ -133,6 +133,8 @@ static void emulate_csb_update(struct intel_vgpu_execlist *execlist,
struct execlist_context_status_pointer_format ctx_status_ptr;
u32 write_pointer;
u32 ctx_status_ptr_reg, ctx_status_buf_reg, offset;
+ unsigned long hwsp_gpa;
+ struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
ctx_status_ptr_reg = execlist_ring_mmio(vgpu->gvt, ring_id,
_EL_OFFSET_STATUS_PTR);
@@ -158,6 +160,20 @@ static void emulate_csb_update(struct intel_vgpu_execlist *execlist,
ctx_status_ptr.write_ptr = write_pointer;
vgpu_vreg(vgpu, ctx_status_ptr_reg) = ctx_status_ptr.dw;
+ /*
+ * Update the CSB and CSB write pointer in HWSP.
+ */
+ if (INTEL_INFO(dev_priv)->gen >= 8) {
+ hwsp_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm,
+ vgpu->hws_pga[ring_id]);
+ intel_gvt_hypervisor_write_gpa(vgpu,
+ hwsp_gpa + I915_HWS_CSB_BUF0_INDEX * 4 +
+ write_pointer * 8,
+ status, 8);
+ intel_gvt_hypervisor_write_gpa(vgpu,
+ hwsp_gpa + intel_hws_csb_write_index(dev_priv) * 4,
+ &write_pointer, 4);
+ }
gvt_dbg_el("vgpu%d: w pointer %u reg %x csb l %x csb h %x\n",
vgpu->id, write_pointer, offset, status->ldw, status->udw);
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index f08d194..27e8186 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -189,6 +189,7 @@ struct intel_vgpu {
struct intel_vgpu_opregion opregion;
struct intel_vgpu_display display;
struct intel_vgpu_submission submission;
+ u32 hws_pga[I915_NUM_ENGINES];
struct dentry *debugfs;
diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index 0fa61a7..c1e79dd 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1371,6 +1371,43 @@ static int mailbox_write(struct intel_vgpu *vgpu, unsigned int offset,
return intel_vgpu_default_mmio_write(vgpu, offset, &value, bytes);
}
+static int hws_pga_write(struct intel_vgpu *vgpu, unsigned int offset,
+ void *p_data, unsigned int bytes)
+{
+ u32 value = *(u32 *)p_data;
+ /*
+ * Need to emulate all the HWSP register write to ensure host can
+ * update the VM CSB status correctly. Here listed registers can
+ * support BDW, SKL or other platforms with same HWSP registers.
+ */
+ switch (offset) {
+ case 0x2080:
+ vgpu->hws_pga[RCS] = value;
+ break;
+ case 0x12080:
+ vgpu->hws_pga[VCS] = value;
+ break;
+ case 0x1c080:
+ vgpu->hws_pga[VCS2] = value;
+ break;
+ case 0x1a080:
+ vgpu->hws_pga[VECS] = value;
+ break;
+ case 0x22080:
+ vgpu->hws_pga[BCS] = value;
+ break;
+ default:
+ gvt_vgpu_err("VM(%d) access unknown hardware status page register:0x%x\n",
+ vgpu->id, offset);
+ return -EINVAL;
+ }
+
+ gvt_dbg_mmio("VM(%d) write: 0x%x to HWSP: 0x%x\n",
+ vgpu->id, value, offset);
+
+ return intel_vgpu_default_mmio_write(vgpu, offset, &value, bytes);
+}
+
static int skl_power_well_ctl_write(struct intel_vgpu *vgpu,
unsigned int offset, void *p_data, unsigned int bytes)
{
@@ -2574,8 +2611,9 @@ static int init_broadwell_mmio_info(struct intel_gvt *gvt)
MMIO_F(RING_REG(GEN8_BSD2_RING_BASE), 32, 0, 0, 0, D_BDW_PLUS, NULL, NULL);
#undef RING_REG
- MMIO_RING_GM_RDR(RING_HWS_PGA, D_BDW_PLUS, NULL, NULL);
- MMIO_GM_RDR(RING_HWS_PGA(GEN8_BSD2_RING_BASE), D_BDW_PLUS, NULL, NULL);
+ MMIO_RING_GM_RDR(RING_HWS_PGA, D_BDW_PLUS, NULL, hws_pga_write);
+ MMIO_GM_RDR(RING_HWS_PGA(GEN8_BSD2_RING_BASE), D_BDW_PLUS, NULL,
+ hws_pga_write);
MMIO_DFH(HDC_CHICKEN0, D_BDW_PLUS, F_MODE_MASK | F_CMD_ACCESS, NULL, NULL);
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 99dbefa..5d180c6 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -43,7 +43,15 @@ void populate_pvinfo_page(struct intel_vgpu *vgpu)
vgpu_vreg(vgpu, vgtif_reg(version_minor)) = 0;
vgpu_vreg(vgpu, vgtif_reg(display_ready)) = 0;
vgpu_vreg(vgpu, vgtif_reg(vgt_id)) = vgpu->id;
+
vgpu_vreg(vgpu, vgtif_reg(vgt_caps)) = VGT_CAPS_FULL_48BIT_PPGTT;
+ /*
+ * Add HWSP emulation support after gen8 platform, VM need to check
+ * this caps to ensure it can read CSB status in HWSP.
+ */
+ if (INTEL_INFO(vgpu->gvt->dev_priv)->gen >= 8)
+ vgpu_vreg(vgpu, vgtif_reg(vgt_caps)) |= VGT_CAPS_HWSP_EMULATION;
+
vgpu_vreg(vgpu, vgtif_reg(avail_rs.mappable_gmadr.base)) =
vgpu_aperture_gmadr_base(vgpu);
vgpu_vreg(vgpu, vgtif_reg(avail_rs.mappable_gmadr.size)) =
diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h b/drivers/gpu/drm/i915/i915_pvinfo.h
index 0679a58..195203f 100644
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -53,6 +53,7 @@ enum vgt_g2v_type {
* VGT capabilities type
*/
#define VGT_CAPS_FULL_48BIT_PPGTT BIT(2)
+#define VGT_CAPS_HWSP_EMULATION BIT(3)
struct vgt_if {
u64 magic; /* VGT_MAGIC */
--
1.9.1
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