diff mbox series

[v4,net-next] vmxnet3: Remove buf_info from device accessible structures

Message ID 20210126190640.26942-1-doshir@vmware.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [v4,net-next] vmxnet3: Remove buf_info from device accessible structures | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 18 this patch: 15
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning WARNING: kfree(NULL) is safe and this check is probably not required
netdev/build_allmodconfig_warn success Errors and warnings before: 18 this patch: 15
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Ronak Doshi Jan. 26, 2021, 7:06 p.m. UTC 
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>
---
Changes in v2:
 - Use kcalloc_node()
 - Remove log for memory allocation failure
Changes in v3:
 - Do not pass __GFP_ZERO to kcalloc
Changes in v4:
 - Modified description to not have subject line
---
 drivers/net/vmxnet3/vmxnet3_drv.c | 37 ++++++++++++-------------------------
 drivers/net/vmxnet3/vmxnet3_int.h |  2 --
 2 files changed, 12 insertions(+), 27 deletions(-)

Comments

Jakub Kicinski Jan. 28, 2021, 12:10 a.m. UTC | #1 
On Tue, 26 Jan 2021 11:06:40 -0800 Ronak Doshi wrote:
> 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>

Checkpatch says:

WARNING: kfree(NULL) is safe and this check is probably not required
#39: FILE: drivers/net/vmxnet3/vmxnet3_drv.c:455:
 	if (tq->buf_info) {
+		kfree(tq->buf_info);

WARNING: kfree(NULL) is safe and this check is probably not required
#73: FILE: drivers/net/vmxnet3/vmxnet3_drv.c:1737:
 	if (rq->buf_info[0]) {
+		kfree(rq->buf_info[0]);


You can remove those ifs as well.
diff mbox series

Patch

diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 336504b7531d..419e81b21d9b 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -452,9 +452,7 @@  vmxnet3_tq_destroy(struct vmxnet3_tx_queue *tq,
 		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);
+		kfree(tq->buf_info);
 		tq->buf_info = NULL;
 	}
 }
@@ -505,8 +503,6 @@  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 +530,9 @@  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;
 
@@ -1738,10 +1734,7 @@  static void vmxnet3_rq_destroy(struct vmxnet3_rx_queue *rq,
 	}
 
 	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);
+		kfree(rq->buf_info[0]);
 		rq->buf_info[0] = rq->buf_info[1] = NULL;
 	}
 }
@@ -1883,10 +1876,9 @@  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 +2514,12 @@  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 +2531,11 @@  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 =
diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h
index d958b92c9429..e910596b79cf 100644
--- a/drivers/net/vmxnet3/vmxnet3_int.h
+++ b/drivers/net/vmxnet3/vmxnet3_int.h
@@ -240,7 +240,6 @@  struct vmxnet3_tx_queue {
 	spinlock_t                      tx_lock;
 	struct vmxnet3_cmd_ring         tx_ring;
 	struct vmxnet3_tx_buf_info      *buf_info;
-	dma_addr_t                       buf_info_pa;
 	struct vmxnet3_tx_data_ring     data_ring;
 	struct vmxnet3_comp_ring        comp_ring;
 	struct Vmxnet3_TxQueueCtrl      *shared;
@@ -298,7 +297,6 @@  struct vmxnet3_rx_queue {
 	u32 qid2;           /* rqID in RCD for buffer from 2nd ring */
 	u32 dataRingQid;    /* rqID in RCD for buffer from data ring */
 	struct vmxnet3_rx_buf_info     *buf_info[2];
-	dma_addr_t                      buf_info_pa;
 	struct Vmxnet3_RxQueueCtrl            *shared;
 	struct vmxnet3_rq_driver_stats  stats;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));