>-----Original Message----- >From: Liu, Yi L <yi.l....@intel.com> >Subject: Re: [PATCH v5 16/21] intel_iommu: Replay pasid bindings after >context cache invalidation > >On 2025/8/28 17:43, Eric Auger wrote: >> >> >> On 8/22/25 8:40 AM, Zhenzhong Duan wrote: >>> From: Yi Liu <yi.l....@intel.com> >>> >>> This replays guest pasid bindings after context cache invalidation. >>> This is a behavior to ensure safety. Actually, programmer should issue >>> pasid cache invalidation with proper granularity after issuing a context >>> cache invalidation. >> So is this mandated? If the spec mandates specific invalidations and the >> guest does not comply with the expected invalidation sequence shall we >> do that behind the curtain? > >I think this is following the below decision. We can discuss if it's >really needed to replay the pasid bind. > >d4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2321) > /* >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2322) * From VT-d spec 6.5.2.1, a global context entry invalidation >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2323) * should be followed by a IOTLB global invalidation, so we >should >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2324) * be safe even without this. Hoewever, let's replay the region as >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2325) * well to be safer, and go back here when we need finer tunes >for >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2326) * VT-d emulation codes. >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2327) */ >dd4d607e40d (Peter Xu 2017-04-07 18:59:15 +0800 >2328) vtd_iommu_replay_all(s);
I have tested this series with this patch reverted, it works with guest linux kernel. Personally, I am inclined to stop adding workaround for guest kenrel bug, there will be more and more over time and it makes current code complex unnecessarily. @Eric, @Liu, Yi L your thought? Thanks Zhenzhong
