Re: [PATCH 1/6] RMDA/sw: don't allow drivers using dma_virt_ops on highmem configs

["Bernard Metzler" <BMT@zurich.ibm.com>]

-----"Christoph Hellwig" <hch@lst.de> wrote: -----

>To: "Jason Gunthorpe" <jgg@ziepe.ca>
>From: "Christoph Hellwig" <hch@lst.de>
>Date: 11/05/2020 08:46AM
>Cc: "Bjorn Helgaas" <bhelgaas@google.com>, "Bernard Metzler"
><bmt@zurich.ibm.com>, "Zhu Yanjun" <yanjunz@nvidia.com>, "Logan
>Gunthorpe" <logang@deltatee.com>, "Dennis Dalessandro"
><dennis.dalessandro@cornelisnetworks.com>, "Mike Marciniszyn"
><mike.marciniszyn@cornelisnetworks.com>, linux-rdma@vger.kernel.org,
>linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org
>Subject: [EXTERNAL] [PATCH 1/6] RMDA/sw: don't allow drivers using
>dma_virt_ops on highmem configs
>
>dma_virt_ops requires that all pages have a kernel virtual address.
>Introduce a INFINIBAND_VIRT_DMA Kconfig symbol that depends on
>!HIGHMEM
>and a large enough dma_addr_t, and make all three driver depend on
>the
>new symbol.
>
>Signed-off-by: Christoph Hellwig <hch@lst.de>
>---
> drivers/infiniband/Kconfig           | 6 ++++++
> drivers/infiniband/sw/rdmavt/Kconfig | 3 ++-
> drivers/infiniband/sw/rxe/Kconfig    | 2 +-
> drivers/infiniband/sw/siw/Kconfig    | 1 +
> 4 files changed, 10 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
>index 32a51432ec4f73..81acaf5fb5be67 100644
>--- a/drivers/infiniband/Kconfig
>+++ b/drivers/infiniband/Kconfig
>@@ -73,6 +73,12 @@ config INFINIBAND_ADDR_TRANS_CONFIGFS
> 	  This allows the user to config the default GID type that the CM
> 	  uses for each device, when initiaing new connections.
> 
>+config INFINIBAND_VIRT_DMA
>+	bool
>+	default y
>+	depends on !HIGHMEM
>+	depends on !64BIT || ARCH_DMA_ADDR_T_64BIT
>+
> if INFINIBAND_USER_ACCESS || !INFINIBAND_USER_ACCESS
> source "drivers/infiniband/hw/mthca/Kconfig"
> source "drivers/infiniband/hw/qib/Kconfig"
>diff --git a/drivers/infiniband/sw/rdmavt/Kconfig
>b/drivers/infiniband/sw/rdmavt/Kconfig
>index 9ef5f5ce1ff6b0..c8e268082952b0 100644
>--- a/drivers/infiniband/sw/rdmavt/Kconfig
>+++ b/drivers/infiniband/sw/rdmavt/Kconfig
>@@ -1,7 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0-only
> config INFINIBAND_RDMAVT
> 	tristate "RDMA verbs transport library"
>-	depends on X86_64 && ARCH_DMA_ADDR_T_64BIT
>+	depends on INFINIBAND_VIRT_DMA
>+	depends on X86_64
> 	depends on PCI
> 	select DMA_VIRT_OPS
> 	help
>diff --git a/drivers/infiniband/sw/rxe/Kconfig
>b/drivers/infiniband/sw/rxe/Kconfig
>index a0c6c7dfc1814f..8810bfa680495a 100644
>--- a/drivers/infiniband/sw/rxe/Kconfig
>+++ b/drivers/infiniband/sw/rxe/Kconfig
>@@ -2,7 +2,7 @@
> config RDMA_RXE
> 	tristate "Software RDMA over Ethernet (RoCE) driver"
> 	depends on INET && PCI && INFINIBAND
>-	depends on !64BIT || ARCH_DMA_ADDR_T_64BIT
>+	depends on INFINIBAND_VIRT_DMA
> 	select NET_UDP_TUNNEL
> 	select CRYPTO_CRC32
> 	select DMA_VIRT_OPS
>diff --git a/drivers/infiniband/sw/siw/Kconfig
>b/drivers/infiniband/sw/siw/Kconfig
>index b622fc62f2cd6d..3450ba5081df51 100644
>--- a/drivers/infiniband/sw/siw/Kconfig
>+++ b/drivers/infiniband/sw/siw/Kconfig
>@@ -1,6 +1,7 @@
> config RDMA_SIW
> 	tristate "Software RDMA over TCP/IP (iWARP) driver"
> 	depends on INET && INFINIBAND && LIBCRC32C
>+	depends on INFINIBAND_VIRT_DMA
> 	select DMA_VIRT_OPS
> 	help
> 	This driver implements the iWARP RDMA transport over
>-- 
>2.28.0
>
>


The complete patch set works for siw. Tested with siw as
nvmef target.

Tested-by: Bernard Metzler <bmt@zurich.ibm.com>