Re: [dpdk-dev] [PATCH] bus/pci: fix vfio mode

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/30/2017 1:06 AM, Gaëtan Rivet wrote:
> Hi Jerin,
> 
> On Sat, Oct 28, 2017 at 11:50:52AM +0530, Jerin Jacob wrote:
>> The definition of VFIO_PRESENT is "eal_vfio.h", Fail to
>> include eal_vfio.h will result in disabling vfio.
>>
>> Fixes: 279b581c897d ("vfio: expose functions")
>>
> 
> Thanks for the fix, sorry for VFIO.
> I tried to let go of VFIO_PRESENT in the PCI patchset, unfortunately I did
> not do a good-enough job.
> 
> Instead of reinstating the dependency on the private eal_vfio.h header,
> I'd suggest replacing all VFIO_PRESENT references within the PCI bus by
> RTE_EAL_VFIO, and make the pci_vfio.c compilation depend on it within
> the linux Makefile. Something like:
> 
> ---8<---
> 
> grep -rl VFIO_PRESENT drivers/bus/pci/linux/ |while read -r file
> do sed -i 's;VFIO_PRESENT;RTE_EAL_VFIO;' $file
> done

VFIO_PRESENT is the combination of the if user enabled VFIO and if Linux kernel
supports it.

Why not add same check and VFIO_PRESENT definition to rte_vfio.h:

  --- a/lib/librte_eal/common/include/rte_vfio.h
  +++ b/lib/librte_eal/common/include/rte_vfio.h
  @@ -34,7 +34,13 @@
   #ifndef _RTE_VFIO_H_
   #define _RTE_VFIO_H_

  +#if !defined(VFIO_PRESENT) && defined(RTE_EAL_VFIO)
  +#include <linux/version.h>
  +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0)
   #include <linux/vfio.h>
  +#define VFIO_PRESENT
  +#endif /* >= 3.6.0 */
  +#endif
  +
  +#ifdef VFIO_PRESENT

  ... Need to wrap here in case VFIO disabled ...

  #endif

> 
> patch -p1 <<___HERE
> diff --git a/drivers/bus/pci/linux/Makefile b/drivers/bus/pci/linux/Makefile
> index 77c5f97..b5b9c54 100644
> --- a/drivers/bus/pci/linux/Makefile
> +++ b/drivers/bus/pci/linux/Makefile
> @@ -31,6 +31,8 @@
> 
>  SRCS += pci.c
>  SRCS += pci_uio.c
> +ifeq (\$(CONFIG_RTE_EAL_VFIO),y)
>  SRCS += pci_vfio.c
> +endif

+1

Also ?
  +ifeq ($(CONFIG_RTE_EAL_VFIO),y)
   SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_vfio.c
   SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_vfio_mp_sync.c
  +endif

Build shouldn't broken when VFIO disabled form config

> 
>  CFLAGS += -D_GNU_SOURCE
> ___HERE
> 
> --->8---
> 
> Do you think it could work? If so, I think it would be preferable
> to re-including eal_vfio.h. Private EAL headers are bound to be removed
> from other subsystems at some point. I tried to start with VFIO, others
> should follow.
> 
>> Cc: Gaetan Rivet <gaetan.rivet@6wind.com>
>>
>> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
>> ---
>>  drivers/bus/pci/linux/pci.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
>> index cdf810693..d0ce0207a 100644
>> --- a/drivers/bus/pci/linux/pci.c
>> +++ b/drivers/bus/pci/linux/pci.c
>> @@ -46,6 +46,7 @@
>>  
>>  #include "eal_private.h"
>>  #include "eal_filesystem.h"
>> +#include "eal_vfio.h"
>>  
>>  #include "private.h"
>>  #include "pci_init.h"
>> -- 
>> 2.14.3
>>
>