[PATCH v4 7/8] iommu/vt-d: Avoid sending invalid page response

From: Jacob Pan
Date: Thu Nov 21 2019 - 16:22:00 EST


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@xxxxxxxxxxxxxxx>
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Acked-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
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 71b85b892c56..4eecc24412dc 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -686,11 +686,10 @@ 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