[PATCH 5.5 213/399] iommu/vt-d: Avoid sending invalid page response

Greg Kroah-Hartman
2020-02-21T07:52:51Z

From: Jacob Pan <jacob.jun.pan@linux.intel.com>

[ Upstream commit 5f75585e19cc7018bf2016aa771632081ee2f313 ]

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>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 ff7a3f9add325..518d0b2d12afd 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -654,11 +654,10 @@ 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;
}

--
2.20.1