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From:   Jacob Pan <jacob.jun.pan@linux.intel.com>
To:     iommu@lists.linux-foundation.org,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        "Lu Baolu" <baolu.lu@linux.intel.com>,
        David Woodhouse <dwmw2@infradead.org>
Cc:     "Tian, Kevin" <kevin.tian@intel.com>,
        Raj Ashok <ashok.raj@intel.com>, "Yi Liu" <yi.l.liu@intel.com>,
        Eric Auger <eric.auger@redhat.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH v2 09/10] iommu/vt-d: Avoid sending invalid page response
Date:   Mon, 18 Nov 2019 11:42:32 -0800
Message-Id: <1574106153-45867-10-git-send-email-jacob.jun.pan@linux.intel.com>
In-Reply-To: <1574106153-45867-1-git-send-email-jacob.jun.pan@linux.intel.com>
References: <1574106153-45867-1-git-send-email-jacob.jun.pan@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Page responses should only be sent when last page in group (LPIG) or
private data is present in the page request. This patch avoids sending
invalid descriptors.

Fixes: 5d308fc1ecf53 ("iommu/vt-d: Add 256-bit invalidation descriptor
support")
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel-svm.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 26a2f57763ec..098c89246593 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -688,11 +688,10 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 			if (req->priv_data_present)
 				memcpy(&resp.qw2, req->priv_data,
 				       sizeof(req->priv_data));
+			resp.qw2 = 0;
+			resp.qw3 = 0;
+			qi_submit_sync(&resp, iommu);
 		}
-		resp.qw2 = 0;
-		resp.qw3 = 0;
-		qi_submit_sync(&resp, iommu);
-
 		head = (head + sizeof(*req)) & PRQ_RING_MASK;
 	}
 
-- 
2.7.4