From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> [ Upstream commit 1d421058c815d54113d9afdf6db3f995c788cf0d ] The VT-d specification (section 7.6) requires that the value in the Private Data field of a Page Group Response Descriptor must match the value in the Private Data field of the respective Page Request Descriptor. The private data field of a page group response descriptor is set then immediately cleared in prq_event_thread(). This breaks the rule defined by the VT-d specification. Fix it by moving clearing code up. Fixes: 5b438f4ba315d ("iommu/vt-d: Support page request in scalable mode") Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> Reviewed-by: Liu Yi L <yi.l.liu@xxxxxxxxx> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210320024156.640798-1-baolu.lu@xxxxxxxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/intel/svm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 4627437ae1c0..547a6cf57057 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -1031,12 +1031,12 @@ no_pasid: QI_PGRP_RESP_TYPE; resp.qw1 = QI_PGRP_IDX(req->prg_index) | QI_PGRP_LPIG(req->lpig); + resp.qw2 = 0; + resp.qw3 = 0; if (req->priv_data_present) memcpy(&resp.qw2, req->priv_data, sizeof(req->priv_data)); - resp.qw2 = 0; - resp.qw3 = 0; qi_submit_sync(iommu, &resp, 1, 0); } prq_advance: -- 2.30.2