[PATCH v4] bus/pci: fix vfio mode

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

Revert back to using VFIO_PRESENT as a marker to enable compilation
of VFIO-related segments.

VFIO_PRESENT is the combination of user configuration RTE_EAL_VFIO and
kernel version support check.

eal_vfio.h VFIO_PRESENT related check ordered to be compatible with
rte_vfio.h one, no functional modification.

Fixes: 279b581c897d ("vfio: expose functions")

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
v4:

* Alternative to v3, not superseding it, need to decide which one to
get. This one:
  * fixes vfio for new kernels
  * fixes build for old kernels for vfio enabled in config case
  * print warning if vfio enabled in config but not supported by kernel

* Independent from this patch, following may need fixing later
  * Kernel version check for vfio is broken for RTE_KERNELDIR
  * Kernel VFIO support check can be improved
---
 drivers/bus/pci/linux/pci_init.h             |  2 +-
 drivers/bus/pci/linux/pci_vfio.c             |  2 +-
 lib/librte_eal/common/include/rte_vfio.h     | 14 ++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_interrupts.c |  1 -
 lib/librte_eal/linuxapp/eal/eal_vfio.h       | 14 ++++++++++----
 5 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/drivers/bus/pci/linux/pci_init.h b/drivers/bus/pci/linux/pci_init.h
index 99d7a2e86..f342c47de 100644
--- a/drivers/bus/pci/linux/pci_init.h
+++ b/drivers/bus/pci/linux/pci_init.h
@@ -74,7 +74,7 @@ void pci_uio_ioport_write(struct rte_pci_ioport *p,
 			  const void *data, size_t len, off_t offset);
 int pci_uio_ioport_unmap(struct rte_pci_ioport *p);
 
-#ifdef RTE_EAL_VFIO
+#ifdef VFIO_PRESENT
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 10, 0)
 #define RTE_PCI_MSIX_TABLE_BIR    0x7
diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
index 360eed380..13d52a8b1 100644
--- a/drivers/bus/pci/linux/pci_vfio.c
+++ b/drivers/bus/pci/linux/pci_vfio.c
@@ -62,7 +62,7 @@
  * This file is only compiled if CONFIG_RTE_EAL_VFIO is set to "y".
  */
 
-#ifdef RTE_EAL_VFIO
+#ifdef VFIO_PRESENT
 
 #define PAGE_SIZE   (sysconf(_SC_PAGESIZE))
 #define PAGE_MASK   (~(PAGE_SIZE - 1))
diff --git a/lib/librte_eal/common/include/rte_vfio.h b/lib/librte_eal/common/include/rte_vfio.h
index a9b705741..d5934cdd3 100644
--- a/lib/librte_eal/common/include/rte_vfio.h
+++ b/lib/librte_eal/common/include/rte_vfio.h
@@ -34,6 +34,18 @@
 #ifndef _RTE_VFIO_H_
 #define _RTE_VFIO_H_
 
+/*
+ * determine if VFIO is present on the system
+ */
+#if !defined(VFIO_PRESENT) && defined(RTE_EAL_VFIO)
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0)
+#define VFIO_PRESENT
+#endif /* kernel version >= 3.6.0 */
+#endif /* RTE_EAL_VFIO */
+
+#ifdef VFIO_PRESENT
+
 #include <linux/vfio.h>
 
 #define VFIO_DIR "/dev/vfio"
@@ -136,4 +148,6 @@ int vfio_is_enabled(const char *modname);
  */
 int vfio_noiommu_is_enabled(void);
 
+#endif /* VFIO_PRESENT */
+
 #endif /* _RTE_VFIO_H_ */
diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index cdd74ee10..0bebf004b 100644
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -64,7 +64,6 @@
 #include <rte_errno.h>
 #include <rte_spinlock.h>
 #include <rte_pause.h>
-#include <rte_vfio.h>
 
 #include "eal_private.h"
 #include "eal_vfio.h"
diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.h b/lib/librte_eal/linuxapp/eal/eal_vfio.h
index 766d0042d..ba7892b72 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.h
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.h
@@ -37,9 +37,17 @@
 /*
  * determine if VFIO is present on the system
  */
-#ifdef RTE_EAL_VFIO
+#if !defined(VFIO_PRESENT) && defined(RTE_EAL_VFIO)
 #include <linux/version.h>
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0)
+#define VFIO_PRESENT
+#else
+#pragma message("VFIO configured but not supported by this kernel, disabling.")
+#endif /* kernel version >= 3.6.0 */
+#endif /* RTE_EAL_VFIO */
+
+#ifdef VFIO_PRESENT
+
 #include <linux/vfio.h>
 
 #define RTE_VFIO_TYPE1 VFIO_TYPE1_IOMMU
@@ -182,8 +190,6 @@ int vfio_mp_sync_setup(void);
 #define SOCKET_NO_FD 0x1
 #define SOCKET_ERR 0xFF
 
-#define VFIO_PRESENT
-#endif /* kernel version */
-#endif /* RTE_EAL_VFIO */
+#endif /* VFIO_PRESENT */
 
 #endif /* EAL_VFIO_H_ */
-- 
2.13.6