Re: [PATCH v5 11/15] intel_iommu_accel: Bypass PASID entry addition for just deleted entry

[Yi Liu <yi.l.liu@intel.com>]

On 5/9/26 12:08, Zhenzhong Duan wrote:
> For VTD_INV_DESC_PASIDC_G_PASID_SI typed pc_inv_dsc invalidation, if an
> pasid entry is just removed, it can never be a new entry to add. So
> calling vtd_replay_pasid_bind_for_dev() is unnecessary.
> 
> Introduce a new field accel_pce_deleted in VTDPASIDCacheInfo to mark
> this case and to do the bypassing.
> 
> Suggested-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Tested-by: Xudong Hao <xudong.hao@intel.com>
> ---
>   hw/i386/intel_iommu_internal.h |  1 +
>   hw/i386/intel_iommu_accel.c    | 16 +++++++++++++---
>   2 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index 623dc24760..2c716c5297 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -630,6 +630,7 @@ typedef struct VTDPASIDCacheInfo {
>       uint8_t type;
>       uint16_t did;
>       uint32_t pasid;
> +    bool accel_pce_deleted;
>   } VTDPASIDCacheInfo;
>   
>   typedef struct VTDPIOTLBInvInfo {
> diff --git a/hw/i386/intel_iommu_accel.c b/hw/i386/intel_iommu_accel.c
> index 82bfbdf484..07a1e41a95 100644
> --- a/hw/i386/intel_iommu_accel.c
> +++ b/hw/i386/intel_iommu_accel.c
> @@ -302,10 +302,15 @@ static void vtd_accel_fill_pc(VTDHostIOMMUDevice *vtd_hiod, uint32_t pasid,
>       QLIST_INSERT_HEAD(&vtd_hiod->pasid_cache_list, vtd_pce, next);
>   }
>   
> -static void vtd_accel_delete_pc(VTDAccelPASIDCacheEntry *vtd_pce)
> +static void vtd_accel_delete_pc(VTDAccelPASIDCacheEntry *vtd_pce,
> +                                VTDPASIDCacheInfo *pc_info)
>   {
>       QLIST_REMOVE(vtd_pce, next);
>       g_free(vtd_pce);
> +
> +    if (pc_info->type == VTD_INV_DESC_PASIDC_G_PASID_SI) {
> +        pc_info->accel_pce_deleted = true;
> +    }
>   }
>   
>   static void
> @@ -339,7 +344,7 @@ vtd_accel_pasid_cache_invalidate_one(VTDAccelPASIDCacheEntry *vtd_pce,
>            * to be either all-zero or non-present. Either case means existing
>            * pasid cache should be invalidated.
>            */
> -        vtd_accel_delete_pc(vtd_pce);
> +        vtd_accel_delete_pc(vtd_pce, pc_info);
>       }
>   }
>   
> @@ -491,7 +496,12 @@ void vtd_accel_pasid_cache_sync(IntelIOMMUState *s, VTDPASIDCacheInfo *pc_info)
>            * removed.
>            */
>           vtd_accel_pasid_cache_invalidate(vtd_hiod, pc_info);
> -        vtd_accel_replay_pasid_bind_for_dev(vtd_hiod, start, end, pc_info);
> +
> +        if (pc_info->accel_pce_deleted) {
> +            pc_info->accel_pce_deleted = false;
> +        } else {
> +            vtd_accel_replay_pasid_bind_for_dev(vtd_hiod, start, end, pc_info);
> +        }
>       }
>   }
>   

LGTM.

Reviewed-by: Yi Liu <yi.l.liu@intel.com>