Date:   Fri, 17 Mar 2023 14:20:15 +0800
From:   Yan Zhao <yan.y.zhao@intel.com>
To:     Sean Christopherson <seanjc@google.com>
CC:     Paolo Bonzini <pbonzini@redhat.com>,
        Zhenyu Wang <zhenyuw@linux.intel.com>,
        Zhi Wang <zhi.a.wang@intel.com>, <kvm@vger.kernel.org>,
        <intel-gvt-dev@lists.freedesktop.org>,
        <intel-gfx@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
        Ben Gardon <bgardon@google.com>
Subject: Re: [PATCH v2 09/27] drm/i915/gvt: Drop unused helper
 intel_vgpu_reset_gtt()
Message-ID: <ZBQGnz8BXFhrZv+O@yzhao56-desk.sh.intel.com>
Reply-To: Yan Zhao <yan.y.zhao@intel.com>
References: <20230311002258.852397-1-seanjc@google.com>
 <20230311002258.852397-10-seanjc@google.com>
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Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>

On Fri, Mar 10, 2023 at 04:22:40PM -0800, Sean Christopherson wrote:
> Drop intel_vgpu_reset_gtt() as it no longer has any callers.  In addition
> to eliminating dead code, this eliminates the last possible scenario where
> __kvmgt_protect_table_find() can be reached without holding vgpu_lock.
> Requiring vgpu_lock to be held when calling __kvmgt_protect_table_find()
> will allow a protecting the gfn hash with vgpu_lock without too much fuss.
> 
> No functional change intended.
> 
> Fixes: ba25d977571e ("drm/i915/gvt: Do not destroy ppgtt_mm during vGPU D3->D0.")
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  drivers/gpu/drm/i915/gvt/gtt.c | 18 ------------------
>  drivers/gpu/drm/i915/gvt/gtt.h |  1 -
>  2 files changed, 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> index e60bcce241f8..293bb2292021 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.c
> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> @@ -2845,24 +2845,6 @@ void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu, bool invalidate_old)
>  	ggtt_invalidate(gvt->gt);
>  }
>  
> -/**
> - * intel_vgpu_reset_gtt - reset the all GTT related status
> - * @vgpu: a vGPU
> - *
> - * This function is called from vfio core to reset reset all
> - * GTT related status, including GGTT, PPGTT, scratch page.
> - *
> - */
> -void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu)
> -{
> -	/* Shadow pages are only created when there is no page
> -	 * table tracking data, so remove page tracking data after
> -	 * removing the shadow pages.
> -	 */
> -	intel_vgpu_destroy_all_ppgtt_mm(vgpu);
> -	intel_vgpu_reset_ggtt(vgpu, true);
> -}
> -
>  /**
>   * intel_gvt_restore_ggtt - restore all vGPU's ggtt entries
>   * @gvt: intel gvt device
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.h b/drivers/gpu/drm/i915/gvt/gtt.h
> index a3b0f59ec8bd..4cb183e06e95 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.h
> +++ b/drivers/gpu/drm/i915/gvt/gtt.h
> @@ -224,7 +224,6 @@ void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu, bool invalidate_old);
>  void intel_vgpu_invalidate_ppgtt(struct intel_vgpu *vgpu);
>  
>  int intel_gvt_init_gtt(struct intel_gvt *gvt);
> -void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu);
>  void intel_gvt_clean_gtt(struct intel_gvt *gvt);
>  
>  struct intel_vgpu_mm *intel_gvt_find_ppgtt_mm(struct intel_vgpu *vgpu,
> -- 
> 2.40.0.rc1.284.g88254d51c5-goog
>