vmxnet3: Remove buf_info from device accessible structures

buf_info structures in RX & TX queues are private driver data that
do not need to be visible to the device.  Although there is physical
address and length in the queue descriptor that points to these
structures, their layout is not standardized, and device never looks
at them.

So lets allocate these structures in non-DMA-able memory, and fill
physical address as all-ones and length as zero in the queue
descriptor.

That should alleviate worries brought by Martin Radev in
https://lists.osuosl.org/pipermail/intel-wired-lan/Week-of-Mon-20210104/022829.html
that malicious vmxnet3 device could subvert SVM/TDX guarantees.

Signed-off-by: Petr Vandrovec <petr@vmware.com>
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 15 insertions, 31 deletions

diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 336504b7531d..6e87f1fc4874 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -451,12 +451,8 @@ vmxnet3_tq_destroy(struct vmxnet3_tx_queue *tq,
 				  tq->comp_ring.base, tq->comp_ring.basePA);
 		tq->comp_ring.base = NULL;
 	}
-	if (tq->buf_info) {
-		dma_free_coherent(&adapter->pdev->dev,
-				  tq->tx_ring.size * sizeof(tq->buf_info[0]),
-				  tq->buf_info, tq->buf_info_pa);
-		tq->buf_info = NULL;
-	}
+	kfree(tq->buf_info);
+	tq->buf_info = NULL;
 }
 
 
@@ -505,8 +501,6 @@ static int
 vmxnet3_tq_create(struct vmxnet3_tx_queue *tq,
 		  struct vmxnet3_adapter *adapter)
 {
-	size_t sz;
-
 	BUG_ON(tq->tx_ring.base || tq->data_ring.base ||
 	       tq->comp_ring.base || tq->buf_info);
 
@@ -534,9 +528,9 @@ vmxnet3_tq_create(struct vmxnet3_tx_queue *tq,
 		goto err;
 	}
 
-	sz = tq->tx_ring.size * sizeof(tq->buf_info[0]);
-	tq->buf_info = dma_alloc_coherent(&adapter->pdev->dev, sz,
-					  &tq->buf_info_pa, GFP_KERNEL);
+	tq->buf_info = kcalloc_node(tq->tx_ring.size, sizeof(tq->buf_info[0]),
+				    GFP_KERNEL,
+				    dev_to_node(&adapter->pdev->dev));
 	if (!tq->buf_info)
 		goto err;
 
@@ -1737,13 +1731,9 @@ static void vmxnet3_rq_destroy(struct vmxnet3_rx_queue *rq,
 		rq->comp_ring.base = NULL;
 	}
 
-	if (rq->buf_info[0]) {
-		size_t sz = sizeof(struct vmxnet3_rx_buf_info) *
-			(rq->rx_ring[0].size + rq->rx_ring[1].size);
-		dma_free_coherent(&adapter->pdev->dev, sz, rq->buf_info[0],
-				  rq->buf_info_pa);
-		rq->buf_info[0] = rq->buf_info[1] = NULL;
-	}
+	kfree(rq->buf_info[0]);
+	rq->buf_info[0] = NULL;
+	rq->buf_info[1] = NULL;
 }
 
 static void
@@ -1883,10 +1873,9 @@ vmxnet3_rq_create(struct vmxnet3_rx_queue *rq, struct vmxnet3_adapter *adapter)
 		goto err;
 	}
 
-	sz = sizeof(struct vmxnet3_rx_buf_info) * (rq->rx_ring[0].size +
-						   rq->rx_ring[1].size);
-	bi = dma_alloc_coherent(&adapter->pdev->dev, sz, &rq->buf_info_pa,
-				GFP_KERNEL);
+	bi = kcalloc_node(rq->rx_ring[0].size + rq->rx_ring[1].size,
+			  sizeof(rq->buf_info[0][0]), GFP_KERNEL,
+			  dev_to_node(&adapter->pdev->dev));
 	if (!bi)
 		goto err;
 
@@ -2522,14 +2511,12 @@ vmxnet3_setup_driver_shared(struct vmxnet3_adapter *adapter)
 		tqc->txRingBasePA   = cpu_to_le64(tq->tx_ring.basePA);
 		tqc->dataRingBasePA = cpu_to_le64(tq->data_ring.basePA);
 		tqc->compRingBasePA = cpu_to_le64(tq->comp_ring.basePA);
-		tqc->ddPA           = cpu_to_le64(tq->buf_info_pa);
+		tqc->ddPA           = cpu_to_le64(~0ULL);
 		tqc->txRingSize     = cpu_to_le32(tq->tx_ring.size);
 		tqc->dataRingSize   = cpu_to_le32(tq->data_ring.size);
 		tqc->txDataRingDescSize = cpu_to_le32(tq->txdata_desc_size);
 		tqc->compRingSize   = cpu_to_le32(tq->comp_ring.size);
-		tqc->ddLen          = cpu_to_le32(
-					sizeof(struct vmxnet3_tx_buf_info) *
-					tqc->txRingSize);
+		tqc->ddLen          = cpu_to_le32(0);
 		tqc->intrIdx        = tq->comp_ring.intr_idx;
 	}
 
@@ -2541,14 +2528,11 @@ vmxnet3_setup_driver_shared(struct vmxnet3_adapter *adapter)
 		rqc->rxRingBasePA[0] = cpu_to_le64(rq->rx_ring[0].basePA);
 		rqc->rxRingBasePA[1] = cpu_to_le64(rq->rx_ring[1].basePA);
 		rqc->compRingBasePA  = cpu_to_le64(rq->comp_ring.basePA);
-		rqc->ddPA            = cpu_to_le64(rq->buf_info_pa);
+		rqc->ddPA            = cpu_to_le64(~0ULL);
 		rqc->rxRingSize[0]   = cpu_to_le32(rq->rx_ring[0].size);
 		rqc->rxRingSize[1]   = cpu_to_le32(rq->rx_ring[1].size);
 		rqc->compRingSize    = cpu_to_le32(rq->comp_ring.size);
-		rqc->ddLen           = cpu_to_le32(
-					sizeof(struct vmxnet3_rx_buf_info) *
-					(rqc->rxRingSize[0] +
-					 rqc->rxRingSize[1]));
+		rqc->ddLen           = cpu_to_le32(0);
 		rqc->intrIdx         = rq->comp_ring.intr_idx;
 		if (VMXNET3_VERSION_GE_3(adapter)) {
 			rqc->rxDataRingBasePA =