vdpa/mlx5: workaround var offset within page

Message ID 20220314014414.251869-1-yajunw@nvidia.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series vdpa/mlx5: workaround var offset within page |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/iol-mellanox-Performance success Performance Testing PASS
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ci/Intel-compilation success Compilation OK
ci/iol-intel-Functional success Functional Testing PASS
ci/intel-Testing success Testing PASS
ci/iol-intel-Performance fail Performance Testing issues
ci/iol-abi-testing success Testing PASS
ci/iol-aarch64-unit-testing success Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-aarch64-compile-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/iol-broadcom-Functional success Functional Testing PASS
ci/iol-broadcom-Performance success Performance Testing PASS

Commit Message

Yajun Wu March 14, 2022, 1:44 a.m. UTC
  vDPA driver first uses kernel driver to allocate doorbell(VAR) area for
each device. Then uses var->mmap_off and var->length to mmap uverbs device
file as doorbell userspace virtual address.

Current kernel driver provides var->mmap_off equal to page start of VAR.
It's fine with x86 4K page server, because VAR physical address is only 4K
aligned thus locate in 4K page start.

But with aarch64 64K page server, the actual VAR physical address has
offset within page(not locate in 64K page start). So vDPA driver need add
this within page offset(caps.doorbell_bar_offset) to get right VAR virtual
address.

Fixes: 62c813706e4 ("vdpa/mlx5: map doorbell")
Cc: stable@dpdk.org

Signed-off-by: Yajun Wu <yajunw@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa_virtq.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
  

Patch

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
index 3416797d28..0748710a76 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
@@ -9,6 +9,7 @@ 
 #include <rte_malloc.h>
 #include <rte_errno.h>
 #include <rte_io.h>
+#include <rte_eal_paging.h>
 
 #include <mlx5_common.h>
 
@@ -123,7 +124,10 @@  mlx5_vdpa_virtqs_release(struct mlx5_vdpa_priv *priv)
 		priv->td = NULL;
 	}
 	if (priv->virtq_db_addr) {
-		claim_zero(munmap(priv->virtq_db_addr, priv->var->length));
+		/* Mask out the within page offset for ummap. */
+		claim_zero(munmap((void *)((uint64_t)priv->virtq_db_addr &
+			~(rte_mem_page_size() - 1ULL)),
+			priv->var->length));
 		priv->virtq_db_addr = NULL;
 	}
 	priv->features = 0;
@@ -486,6 +490,10 @@  mlx5_vdpa_virtqs_prepare(struct mlx5_vdpa_priv *priv)
 		priv->virtq_db_addr = NULL;
 		goto error;
 	} else {
+		/* Add within page offset for 64K page system. */
+		priv->virtq_db_addr = (char *)priv->virtq_db_addr +
+			((rte_mem_page_size() - 1) &
+			priv->caps.doorbell_bar_offset);
 		DRV_LOG(DEBUG, "VAR address of doorbell mapping is %p.",
 			priv->virtq_db_addr);
 	}