[PATCH] drm/i915/gvt: Enable GVT vGPU enabled guest S3 and resume

Zhenyu Wang zhenyuw at linux.intel.com
Mon May 18 10:32:11 UTC 2020


On 2020.05.18 14:19:10 +0800, Colin Xu wrote:
> This patch enables GVT vGPU enabled guest enter and resume from S3.
> During S3, QEMU process is still active so all ppgtt still in memory
> thus no need to invalidate them. However current ppgtt invalidation and
> destroy logic happens in dmlr, this operation happens during both boot
> and resuming. Thus we need differ these different power states for
> proper handling.
> vCPU PCI cfg space is a modified copy from host. If PM cap is supported
> on host, vGPU cfg space will also report the capability and handle read
> or write request on PMCSR register. On receiving PCI_D3hot when enter S3,
> vGPU will track current PM status. During dmlr, gvt will check if current
> dmrl is during normal boot or S3 resume. If S3 resume, skip the ppgtt mm
> invalidation and destroy so that they can be re-used, then clear the PM
> status flag. PCI_D0 is set prior to dmlr so can't depend on it to skip
> the ppgtt invalidation and destroy operation.
> 
> 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.
> 
> With all required options enabled and proper GFX driver installed, user
> can enter S3 from guest OS, and resume from QEMU monitor using
> system_wakeup.
> 
> Signed-off-by: Hang Yuan <hang.yuan at linux.intel.com>
> Signed-off-by: Colin Xu <colin.xu at intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/cfg_space.c | 24 ++++++++++++++++++++++++
>  drivers/gpu/drm/i915/gvt/gtt.c       |  2 +-
>  drivers/gpu/drm/i915/gvt/gtt.h       |  2 ++
>  drivers/gpu/drm/i915/gvt/gvt.h       |  3 +++
>  drivers/gpu/drm/i915/gvt/vgpu.c      | 21 ++++++++++++++++++---
>  5 files changed, 48 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/cfg_space.c b/drivers/gpu/drm/i915/gvt/cfg_space.c
> index 072725a448db..ad86c5eb5bba 100644
> --- a/drivers/gpu/drm/i915/gvt/cfg_space.c
> +++ b/drivers/gpu/drm/i915/gvt/cfg_space.c
> @@ -70,6 +70,7 @@ static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off,
>  {
>  	u8 *cfg_base = vgpu_cfg_space(vgpu);
>  	u8 mask, new, old;
> +	pci_power_t pwr;
>  	int i = 0;
>  
>  	for (; i < bytes && (off + i < sizeof(pci_cfg_space_rw_bmp)); i++) {
> @@ -91,6 +92,15 @@ static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off,
>  	/* For other configuration space directly copy as it is. */
>  	if (i < bytes)
>  		memcpy(cfg_base + off + i, src + i, bytes - i);
> +
> +	if (off == vgpu->cfg_space.pmcsr_off && vgpu->cfg_space.pmcsr_off) {
> +		pwr = (pci_power_t __force)(*(u16*)(&vgpu_cfg_space(vgpu)[off])
> +			& PCI_PM_CTRL_STATE_MASK);
> +		if (pwr == PCI_D3hot)
> +			vgpu->d3_entered = true;
> +		gvt_dbg_core("vgpu-%d power status changed to %d\n",
> +			     vgpu->id, pwr);
> +	}

Good for tracking PM state, that's exactly what I expected. But how about
other Dx state? e.g if guest wants to do suspend-to-idle, would it hit same
penalty for ppgtt invalidate?

>  }
>  
>  /**
> @@ -366,6 +376,7 @@ void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
>  	struct intel_gvt *gvt = vgpu->gvt;
>  	const struct intel_gvt_device_info *info = &gvt->device_info;
>  	u16 *gmch_ctl;
> +	u8 next;
>  
>  	memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
>  	       info->cfg_space_size);
> @@ -401,6 +412,19 @@ void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
>  		pci_resource_len(gvt->gt->i915->drm.pdev, 2);
>  
>  	memset(vgpu_cfg_space(vgpu) + PCI_ROM_ADDRESS, 0, 4);
> +
> +	/* PM Support */
> +	vgpu->cfg_space.pmcsr_off = 0;
> +	if (vgpu_cfg_space(vgpu)[PCI_STATUS] & PCI_STATUS_CAP_LIST) {
> +		next = vgpu_cfg_space(vgpu)[PCI_CAPABILITY_LIST];
> +		do {
> +			if (vgpu_cfg_space(vgpu)[next + PCI_CAP_LIST_ID] == PCI_CAP_ID_PM) {
> +				vgpu->cfg_space.pmcsr_off = next + PCI_PM_CTRL;
> +				break;
> +			}
> +			next = vgpu_cfg_space(vgpu)[next + PCI_CAP_LIST_NEXT];
> +		} while (next);
> +	}
>  }
>  
>  /**
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> index 210016192ce7..a3a4305eda01 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.c
> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> @@ -2501,7 +2501,7 @@ int intel_vgpu_init_gtt(struct intel_vgpu *vgpu)
>  	return create_scratch_page_tree(vgpu);
>  }
>  
> -static void intel_vgpu_destroy_all_ppgtt_mm(struct intel_vgpu *vgpu)
> +void intel_vgpu_destroy_all_ppgtt_mm(struct intel_vgpu *vgpu)
>  {
>  	struct list_head *pos, *n;
>  	struct intel_vgpu_mm *mm;
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.h b/drivers/gpu/drm/i915/gvt/gtt.h
> index 320b8d6ad92f..52d0d88abd86 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.h
> +++ b/drivers/gpu/drm/i915/gvt/gtt.h
> @@ -279,4 +279,6 @@ int intel_vgpu_emulate_ggtt_mmio_read(struct intel_vgpu *vgpu,
>  int intel_vgpu_emulate_ggtt_mmio_write(struct intel_vgpu *vgpu,
>  	unsigned int off, void *p_data, unsigned int bytes);
>  
> +void intel_vgpu_destroy_all_ppgtt_mm(struct intel_vgpu *vgpu);
> +
>  #endif /* _GVT_GTT_H_ */
> 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;
>  
> diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
> index 1d5ff88078bd..3779f9f28061 100644
> --- a/drivers/gpu/drm/i915/gvt/vgpu.c
> +++ b/drivers/gpu/drm/i915/gvt/vgpu.c
> @@ -257,7 +257,9 @@ void intel_gvt_release_vgpu(struct intel_vgpu *vgpu)
>  	intel_gvt_deactivate_vgpu(vgpu);
>  
>  	mutex_lock(&vgpu->vgpu_lock);
> +	vgpu->d3_entered = false;
>  	intel_vgpu_clean_workloads(vgpu, ALL_ENGINES);
> +	intel_vgpu_destroy_all_ppgtt_mm(vgpu);

I think this is good to do when release vGPU, but should be in a split patch.

>  	intel_vgpu_dmabuf_cleanup(vgpu);
>  	mutex_unlock(&vgpu->vgpu_lock);
>  }
> @@ -393,6 +395,7 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
>  	INIT_RADIX_TREE(&vgpu->page_track_tree, GFP_KERNEL);
>  	idr_init(&vgpu->object_idr);
>  	intel_vgpu_init_cfg_space(vgpu, param->primary);
> +	vgpu->d3_entered = false;
>  
>  	ret = intel_vgpu_init_mmio(vgpu);
>  	if (ret)
> @@ -557,10 +560,15 @@ void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr,
>  	/* full GPU reset or device model level reset */
>  	if (engine_mask == ALL_ENGINES || dmlr) {
>  		intel_vgpu_select_submission_ops(vgpu, ALL_ENGINES, 0);
> -		intel_vgpu_invalidate_ppgtt(vgpu);
> +		if (engine_mask == ALL_ENGINES)
> +			intel_vgpu_invalidate_ppgtt(vgpu);
>  		/*fence will not be reset during virtual reset */
>  		if (dmlr) {
> -			intel_vgpu_reset_gtt(vgpu);
> +			if(!vgpu->d3_entered) {
> +				intel_vgpu_invalidate_ppgtt(vgpu);
> +				intel_vgpu_destroy_all_ppgtt_mm(vgpu);
> +			}
> +			intel_vgpu_reset_ggtt(vgpu, true);
>  			intel_vgpu_reset_resource(vgpu);
>  		}
>  
> @@ -572,7 +580,14 @@ void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr,
>  			intel_vgpu_reset_cfg_space(vgpu);
>  			/* only reset the failsafe mode when dmlr reset */
>  			vgpu->failsafe = false;
> -			vgpu->pv_notified = false;
> +			/*
> +			 * PCI_D0 is set before dmlr, so reset d3_entered here
> +			 * after done using.
> +			 */
> +			if(vgpu->d3_entered)
> +				vgpu->d3_entered = false;
> +			else
> +				vgpu->pv_notified = false;
>  		}
>  	}
>  
> -- 
> 2.26.2
> 
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> intel-gvt-dev mailing list
> intel-gvt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

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