drm/i915/gvt: Do not destroy ppgtt_mm during vGPU D3->D0.

When system enters S3 state, device enters D3 state while RAM remains
powered. From vGPU/GVT perspective, ppgtt_mm is residual in guest memory
during vGPU in D3 state, so that when guest state transits from S3->S0,
ppgtt_mm can be re-used and no need rebuild.

Previous implementation invalidate and destroy ppgtt_mm at DMLR,
regardless the power state transition is S0->S3->S0 (guest suspend or
resume) or OFF->S0 (normal boot/reboot), invalidate and destroy ppgtt_mm
is unnecessary in the former transition case.

The patch saves the vGPU D3/D0 transition state when guest writes the
PCI_PM_CTRL in vGPU's configure space, then in later DMLR, GVT can decide
whether or not invalidate and destroy ppgtt_mm is required. The
d3_entered flags is reset after DMLR.

To test this feature, make sure S3 is enabled in QEMU parameters:
i440fx: PIIX4_PM.disable_s3=0
q35: ICH9-LPC.disable_s3=0
Also need enable sleep option in guest OS if it's disabled.

v2:
- Revise commit message to more accurate description. (Kevin)
- Split patch by logic. (Zhenyu)

Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200709071002.247960-2-colin.xu@intel.com

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index a4a6db6b7f90..ff7f2515a6fe 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -106,6 +106,7 @@ struct intel_vgpu_pci_bar {
 struct intel_vgpu_cfg_space {
 	unsigned char virtual_cfg_space[PCI_CFG_SPACE_EXP_SIZE];
 	struct intel_vgpu_pci_bar bar[INTEL_GVT_MAX_BAR_NUM];
+	u32 pmcsr_off;
 };
 
 #define vgpu_cfg_space(vgpu) ((vgpu)->cfg_space.virtual_cfg_space)
@@ -198,6 +199,8 @@ struct intel_vgpu {
 	struct intel_vgpu_submission submission;
 	struct radix_tree_root page_track_tree;
 	u32 hws_pga[I915_NUM_ENGINES];
+	/* Set on PCI_D3, reset on DMLR, not reflecting the actual PM state */
+	bool d3_entered;
 
 	struct dentry *debugfs;