vlib: vfio code rework

Change-Id: I99cf3e7cc991aa7d32385a155c707a6516516117
Signed-off-by: Damjan Marion <damarion@cisco.com>

4 files changed, 387 insertions, 210 deletions

diff --git a/src/vlib/linux/pci.c b/src/vlib/linux/pci.c
index 8aa0e29248c..bc3e15ea00d 100644
--- a/src/vlib/linux/pci.c
+++ b/src/vlib/linux/pci.c
@@ -42,6 +42,7 @@
 #include <vlib/vlib.h>
 #include <vlib/pci/pci.h>
 #include <vlib/unix/unix.h>
+#include <vlib/linux/vfio.h>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -115,29 +116,12 @@ typedef struct
 
 } linux_pci_device_t;
 
-typedef struct
-{
-  int group;
-  int fd;
-  int refcnt;
-} linux_pci_vfio_iommu_group_t;
-
 /* Pool of PCI devices. */
 typedef struct
 {
   vlib_main_t *vlib_main;
   linux_pci_device_t *linux_pci_devices;
 
-  /* VFIO */
-  int vfio_container_fd;
-  int vfio_iommu_mode;
-
-  /* pool of IOMMU groups */
-  linux_pci_vfio_iommu_group_t *iommu_groups;
-
-  /* iommu group pool index by group id  hash */
-  uword *iommu_pool_index_by_group;
-
 } linux_pci_main_t;
 
 extern linux_pci_main_t linux_pci_main;
@@ -180,7 +164,7 @@ linux_pci_main_t linux_pci_main;
 vlib_pci_device_info_t *
 vlib_pci_get_device_info (vlib_pci_addr_t * addr, clib_error_t ** error)
 {
-  linux_pci_main_t *lpm = &linux_pci_main;
+  linux_vfio_main_t *lvm = &vfio_main;
   clib_error_t *err;
   vlib_pci_device_info_t *di;
   u8 *f = 0;
@@ -271,7 +255,7 @@ vlib_pci_get_device_info (vlib_pci_addr_t * addr, clib_error_t ** error)
   di->driver_name = clib_sysfs_link_to_name ((char *) f);
 
   di->iommu_group = -1;
-  if (lpm->vfio_container_fd != -1)
+  if (lvm->container_fd != -1)
     {
       u8 *tmpstr;
       vec_reset_length (f);
@@ -862,91 +846,11 @@ vlib_pci_disable_msix_irq (vlib_pci_dev_handle_t h, u16 start, u16 count)
 			VFIO_IRQ_SET_ACTION_TRIGGER, fds);
 }
 
-static linux_pci_vfio_iommu_group_t *
-get_vfio_iommu_group (int group)
-{
-  linux_pci_main_t *lpm = &linux_pci_main;
-  uword *p;
-
-  p = hash_get (lpm->iommu_pool_index_by_group, group);
-
-  return p ? pool_elt_at_index (lpm->iommu_groups, p[0]) : 0;
-}
-
-static clib_error_t *
-open_vfio_iommu_group (int group)
-{
-  linux_pci_main_t *lpm = &linux_pci_main;
-  linux_pci_vfio_iommu_group_t *g;
-  clib_error_t *err = 0;
-  struct vfio_group_status group_status;
-  u8 *s = 0;
-  int fd;
-
-  g = get_vfio_iommu_group (group);
-  if (g)
-    {
-      g->refcnt++;
-      return 0;
-    }
-  s = format (s, "/dev/vfio/%u%c", group, 0);
-  fd = open ((char *) s, O_RDWR);
-  if (fd < 0)
-    return clib_error_return_unix (0, "open '%s'", s);
-
-  group_status.argsz = sizeof (group_status);
-  if (ioctl (fd, VFIO_GROUP_GET_STATUS, &group_status) < 0)
-    {
-      err = clib_error_return_unix (0, "ioctl(VFIO_GROUP_GET_STATUS) '%s'",
-				    s);
-      goto error;
-    }
-
-  if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE))
-    {
-      err = clib_error_return (0, "iommu group %d is not viable (not all "
-			       "devices in this group bound to vfio-pci)",
-			       group);
-      goto error;
-    }
-
-  if (ioctl (fd, VFIO_GROUP_SET_CONTAINER, &lpm->vfio_container_fd) < 0)
-    {
-      err = clib_error_return_unix (0, "ioctl(VFIO_GROUP_SET_CONTAINER) '%s'",
-				    s);
-      goto error;
-    }
-
-  if (lpm->vfio_iommu_mode == 0)
-    {
-      if (ioctl (lpm->vfio_container_fd, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU) <
-	  0)
-	{
-	  err = clib_error_return_unix (0, "ioctl(VFIO_SET_IOMMU) "
-					"'/dev/vfio/vfio'");
-	  goto error;
-	}
-      lpm->vfio_iommu_mode = VFIO_TYPE1_IOMMU;
-    }
-
-
-  pool_get (lpm->iommu_groups, g);
-  g->fd = fd;
-  g->refcnt = 1;
-  hash_set (lpm->iommu_pool_index_by_group, group, g - lpm->iommu_groups);
-  vec_free (s);
-  return 0;
-error:
-  close (fd);
-  return err;
-}
-
 static clib_error_t *
 add_device_vfio (linux_pci_device_t * p, vlib_pci_device_info_t * di,
 		 pci_device_registration_t * r)
 {
   linux_pci_main_t *lpm = &linux_pci_main;
-  linux_pci_vfio_iommu_group_t *g;
   struct vfio_device_info device_info = { 0 };
   clib_error_t *err = 0;
   u8 *s = 0;
@@ -960,20 +864,9 @@ add_device_vfio (linux_pci_device_t * p, vlib_pci_device_info_t * di,
 			      "vfio-pci", format_vlib_pci_addr, &di->addr,
 			      di->iommu_group);
 
-  if ((err = open_vfio_iommu_group (di->iommu_group)))
+  if ((err = linux_vfio_group_get_device_fd (&p->addr, &p->fd)))
     return err;
 
-  g = get_vfio_iommu_group (di->iommu_group);
-
-  s = format (s, "%U%c", format_vlib_pci_addr, &di->addr, 0);
-  if ((p->fd = ioctl (g->fd, VFIO_GROUP_GET_DEVICE_FD, (char *) s)) < 0)
-    {
-      err = clib_error_return_unix (0, "ioctl(VFIO_GROUP_GET_DEVICE_FD) '%U'",
-				    format_vlib_pci_addr, &di->addr);
-      goto error;
-    }
-  vec_reset_length (s);
-
   device_info.argsz = sizeof (device_info);
   if (ioctl (p->fd, VFIO_DEVICE_GET_INFO, &device_info) < 0)
     {
@@ -1235,10 +1128,8 @@ clib_error_t *
 linux_pci_init (vlib_main_t * vm)
 {
   vlib_pci_main_t *pm = &pci_main;
-  linux_pci_main_t *lpm = &linux_pci_main;
   vlib_pci_addr_t *addr = 0, *addrs;
   clib_error_t *error;
-  int fd;
 
   pm->vlib_main = vm;
 
@@ -1247,23 +1138,6 @@ linux_pci_init (vlib_main_t * vm)
 
   ASSERT (sizeof (vlib_pci_addr_t) == sizeof (u32));
 
-  fd = open ("/dev/vfio/vfio", O_RDWR);
-
-  if ((fd != -1) && (ioctl (fd, VFIO_GET_API_VERSION) != VFIO_API_VERSION))
-    {
-      close (fd);
-      fd = -1;
-    }
-
-  if ((fd != -1) && (ioctl (fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) == 0))
-    {
-      close (fd);
-      fd = -1;
-    }
-
-  lpm->vfio_container_fd = fd;
-  lpm->iommu_pool_index_by_group = hash_create (0, sizeof (uword));
-
   addrs = vlib_pci_get_all_dev_addrs ();
   /* *INDENT-OFF* */
   vec_foreach (addr, addrs)
diff --git a/src/vlib/linux/physmem.c b/src/vlib/linux/physmem.c
index 72b00e24d09..f60a6f75adf 100644
--- a/src/vlib/linux/physmem.c
+++ b/src/vlib/linux/physmem.c
@@ -43,7 +43,6 @@
 #include <sys/mman.h>
 #include <sys/fcntl.h>
 #include <sys/stat.h>
-#include <linux/vfio.h>
 #include <unistd.h>
 
 #include <vppinfra/linux/syscall.h>
@@ -51,8 +50,8 @@
 #include <vlib/vlib.h>
 #include <vlib/physmem.h>
 #include <vlib/unix/unix.h>
-
-static int vfio_container_fd = -1;
+#include <vlib/pci/pci.h>
+#include <vlib/linux/vfio.h>
 
 static void *
 unix_physmem_alloc_aligned (vlib_main_t * vm, vlib_physmem_region_index_t idx,
@@ -79,9 +78,6 @@ unix_physmem_alloc_aligned (vlib_main_t * vm, vlib_physmem_region_index_t idx,
       if (lo_offset == ~0)
 	break;
 
-      if (pr->flags & VLIB_PHYSMEM_F_FAKE)
-	break;
-
       /* Make sure allocation does not span DMA physical chunk boundary. */
       hi_offset = lo_offset + n_bytes - 1;
 
@@ -114,56 +110,6 @@ unix_physmem_free (vlib_main_t * vm, vlib_physmem_region_index_t idx, void *x)
 }
 
 static clib_error_t *
-scan_vfio_fd (void *arg, u8 * path_name, u8 * file_name)
-{
-  const char fn[] = "/dev/vfio/vfio";
-  char buff[sizeof (fn)] = { 0 };
-
-  if (readlink ((char *) path_name, buff, sizeof (fn)) + 1 != sizeof (fn))
-    return 0;
-
-  if (strncmp (fn, buff, sizeof (fn)))
-    return 0;
-
-  vfio_container_fd = atoi ((char *) file_name);
-  return 0;
-}
-
-static clib_error_t *
-unix_physmem_region_iommu_register (vlib_physmem_region_t * pr)
-{
-  struct vfio_iommu_type1_dma_map dma_map = { 0 };
-  int i, fd;
-
-  if (vfio_container_fd == -1)
-    foreach_directory_file ("/proc/self/fd", scan_vfio_fd, 0, 0);
-
-  fd = vfio_container_fd;
-
-  if (fd < 0)
-    return 0;
-
-  if (ioctl (fd, VFIO_GET_API_VERSION) != VFIO_API_VERSION)
-    return 0;
-
-  if (ioctl (fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) == 0)
-    return 0;
-
-  dma_map.argsz = sizeof (struct vfio_iommu_type1_dma_map);
-  dma_map.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
-
-  vec_foreach_index (i, pr->page_table)
-  {
-    dma_map.vaddr = pointer_to_uword (pr->mem) + (i << pr->log2_page_size);
-    dma_map.size = 1 << pr->log2_page_size;
-    dma_map.iova = pr->page_table[i];
-    if (ioctl (fd, VFIO_IOMMU_MAP_DMA, &dma_map) != 0)
-      return clib_error_return_unix (0, "ioctl (VFIO_IOMMU_MAP_DMA)");
-  }
-  return 0;
-}
-
-static clib_error_t *
 unix_physmem_region_alloc (vlib_main_t * vm, char *name, u32 size,
 			   u8 numa_node, u32 flags,
 			   vlib_physmem_region_index_t * idx)
@@ -172,10 +118,7 @@ unix_physmem_region_alloc (vlib_main_t * vm, char *name, u32 size,
   vlib_physmem_region_t *pr;
   clib_error_t *error = 0;
   clib_mem_vm_alloc_t alloc = { 0 };
-
-
-  if (geteuid () != 0 && (flags & VLIB_PHYSMEM_F_FAKE) == 0)
-    return clib_error_return (0, "not allowed");
+  int i;
 
   pool_get (vpm->regions, pr);
 
@@ -188,9 +131,11 @@ unix_physmem_region_alloc (vlib_main_t * vm, char *name, u32 size,
   alloc.name = name;
   alloc.size = size;
   alloc.numa_node = numa_node;
-  alloc.flags = CLIB_MEM_VM_F_SHARED;
 
-  if ((flags & VLIB_PHYSMEM_F_FAKE) == 0)
+  alloc.flags = (flags & VLIB_PHYSMEM_F_SHARED) ?
+    CLIB_MEM_VM_F_SHARED : CLIB_MEM_VM_F_LOCKED;
+
+  if ((flags & VLIB_PHYSMEM_F_HUGETLB))
     {
       alloc.flags |= CLIB_MEM_VM_F_HUGETLB;
       alloc.flags |= CLIB_MEM_VM_F_HUGETLB_PREALLOC;
@@ -216,29 +161,30 @@ unix_physmem_region_alloc (vlib_main_t * vm, char *name, u32 size,
   pr->numa_node = numa_node;
   pr->name = format (0, "%s", name);
 
-  if ((flags & VLIB_PHYSMEM_F_FAKE) == 0)
+  for (i = 0; i < pr->n_pages; i++)
     {
-      int i;
-      for (i = 0; i < pr->n_pages; i++)
+      void *ptr = pr->mem + (i << pr->log2_page_size);
+      int node;
+      if ((move_pages (0, 1, &ptr, 0, &node, 0) == 0) && (numa_node != node))
 	{
-	  void *ptr = pr->mem + (i << pr->log2_page_size);
-	  int node;
-	  if ((move_pages (0, 1, &ptr, 0, &node, 0) == 0) &&
-	      (numa_node != node))
-	    {
-	      clib_warning ("physmem page for region \'%s\' allocated on the"
-			    " wrong numa node (requested %u actual %u)",
-			    pr->name, pr->numa_node, node, i);
-	      break;
-	    }
+	  clib_warning ("physmem page for region \'%s\' allocated on the"
+			" wrong numa node (requested %u actual %u)",
+			pr->name, pr->numa_node, node, i);
+	  break;
 	}
-      pr->page_table = clib_mem_vm_get_paddr (pr->mem, pr->log2_page_size,
-					      pr->n_pages);
-      error = unix_physmem_region_iommu_register (pr);
-      if (error)
-	clib_error_report (error);
     }
 
+  if ((vpm->flags & VLIB_PHYSMEM_MAIN_F_HAVE_IOMMU) ||
+      (vpm->flags & VLIB_PHYSMEM_MAIN_F_HAVE_PAGEMAP) == 0)
+    for (i = 0; i < pr->n_pages; i++)
+      vec_add1 (pr->page_table, pointer_to_uword (pr->mem) +
+		i * (1 << pr->log2_page_size));
+  else
+    pr->page_table = clib_mem_vm_get_paddr (pr->mem, pr->log2_page_size,
+					    pr->n_pages);
+
+  linux_vfio_dma_map_regions (vm);
+
   if (flags & VLIB_PHYSMEM_F_INIT_MHEAP)
     {
       pr->heap = mheap_alloc_with_flags (pr->mem, pr->size,
@@ -275,12 +221,27 @@ unix_physmem_region_free (vlib_main_t * vm, vlib_physmem_region_index_t idx)
 clib_error_t *
 unix_physmem_init (vlib_main_t * vm)
 {
+  vlib_physmem_main_t *vpm = &vm->physmem_main;
+  linux_vfio_main_t *lvm = &vfio_main;
   clib_error_t *error = 0;
+  u64 *pt = 0;
 
   /* Avoid multiple calls. */
   if (vm->os_physmem_alloc_aligned)
     return error;
 
+  /* check if pagemap is accessible */
+  pt = clib_mem_vm_get_paddr (&pt, min_log2 (sysconf (_SC_PAGESIZE)), 1);
+  if (pt[0])
+    vpm->flags |= VLIB_PHYSMEM_MAIN_F_HAVE_PAGEMAP;
+  vec_free (pt);
+
+  if ((error = linux_vfio_init (vm)))
+    return error;
+
+  if (lvm->flags & LINUX_VFIO_F_HAVE_IOMMU)
+    vpm->flags |= VLIB_PHYSMEM_MAIN_F_HAVE_IOMMU;
+
   vm->os_physmem_alloc_aligned = unix_physmem_alloc_aligned;
   vm->os_physmem_free = unix_physmem_free;
   vm->os_physmem_region_alloc = unix_physmem_region_alloc;
diff --git a/src/vlib/linux/vfio.c b/src/vlib/linux/vfio.c
new file mode 100644
index 00000000000..dffe49ce7b2
--- /dev/null
+++ b/src/vlib/linux/vfio.c
@@ -0,0 +1,282 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * pci.c: Linux user space PCI bus management.
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <linux/vfio.h>
+#include <sys/ioctl.h>
+
+#include <vppinfra/linux/sysfs.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vlib/pci/pci.h>
+#include <vlib/linux/vfio.h>
+#include <vlib/physmem.h>
+
+linux_vfio_main_t vfio_main;
+
+static int
+map_regions (vlib_main_t * vm, int fd)
+{
+  vlib_physmem_main_t *vpm = &vm->physmem_main;
+  vlib_physmem_region_t *pr;
+  struct vfio_iommu_type1_dma_map dm = { 0 };
+  int i;
+
+  dm.argsz = sizeof (struct vfio_iommu_type1_dma_map);
+  dm.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
+
+  /* *INDENT-OFF* */
+  pool_foreach (pr, vpm->regions,
+    {
+      vec_foreach_index (i, pr->page_table)
+        {
+	  int rv;
+	  dm.vaddr = pointer_to_uword (pr->mem) + (i << pr->log2_page_size);
+	  dm.size = 1 << pr->log2_page_size;
+	  dm.iova = pr->page_table[i];
+	  if ((rv = ioctl (fd, VFIO_IOMMU_MAP_DMA, &dm)))
+	    return rv;
+        }
+    });
+  /* *INDENT-ON* */
+  return 0;
+}
+
+static clib_error_t *
+scan_vfio_fd (void *arg, u8 * path_name, u8 * file_name)
+{
+  linux_vfio_main_t *lvm = &vfio_main;
+  const char fn[] = "/dev/vfio/vfio";
+  char buff[sizeof (fn)] = { 0 };
+  int fd;
+  u8 *path = format (0, "%v%c", path_name, 0);
+
+  if (readlink ((char *) path, buff, sizeof (fn)) + 1 != sizeof (fn))
+    goto done;
+
+  if (strncmp (fn, buff, sizeof (fn)))
+    goto done;
+
+  fd = atoi ((char *) file_name);
+  if (fd != lvm->container_fd)
+    lvm->ext_container_fd = atoi ((char *) file_name);
+
+done:
+  vec_free (path);
+  return 0;
+}
+
+void
+linux_vfio_dma_map_regions (vlib_main_t * vm)
+{
+  linux_vfio_main_t *lvm = &vfio_main;
+
+  if (lvm->container_fd != -1)
+    map_regions (vm, lvm->container_fd);
+
+  if (lvm->ext_container_fd == -1)
+    foreach_directory_file ("/proc/self/fd", scan_vfio_fd, 0, 0);
+
+  if (lvm->ext_container_fd != -1)
+    map_regions (vm, lvm->ext_container_fd);
+}
+
+static linux_pci_vfio_iommu_group_t *
+get_vfio_iommu_group (int group)
+{
+  linux_vfio_main_t *lvm = &vfio_main;
+  uword *p;
+
+  p = hash_get (lvm->iommu_pool_index_by_group, group);
+
+  return p ? pool_elt_at_index (lvm->iommu_groups, p[0]) : 0;
+}
+
+static clib_error_t *
+open_vfio_iommu_group (int group)
+{
+  linux_vfio_main_t *lvm = &vfio_main;
+  linux_pci_vfio_iommu_group_t *g;
+  clib_error_t *err = 0;
+  struct vfio_group_status group_status;
+  u8 *s = 0;
+  int fd;
+
+  g = get_vfio_iommu_group (group);
+  if (g)
+    {
+      g->refcnt++;
+      return 0;
+    }
+  s = format (s, "/dev/vfio/%u%c", group, 0);
+  fd = open ((char *) s, O_RDWR);
+  if (fd < 0)
+    return clib_error_return_unix (0, "open '%s'", s);
+
+  group_status.argsz = sizeof (group_status);
+  if (ioctl (fd, VFIO_GROUP_GET_STATUS, &group_status) < 0)
+    {
+      err = clib_error_return_unix (0, "ioctl(VFIO_GROUP_GET_STATUS) '%s'",
+				    s);
+      goto error;
+    }
+
+  if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE))
+    {
+      err = clib_error_return (0, "iommu group %d is not viable (not all "
+			       "devices in this group bound to vfio-pci)",
+			       group);
+      goto error;
+    }
+
+  if (ioctl (fd, VFIO_GROUP_SET_CONTAINER, &lvm->container_fd) < 0)
+    {
+      err = clib_error_return_unix (0, "ioctl(VFIO_GROUP_SET_CONTAINER) '%s'",
+				    s);
+      goto error;
+    }
+
+  if (lvm->iommu_mode == 0)
+    {
+      if (ioctl (lvm->container_fd, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU) < 0)
+	{
+	  err = clib_error_return_unix (0, "ioctl(VFIO_SET_IOMMU) "
+					"'/dev/vfio/vfio'");
+	  goto error;
+	}
+      lvm->iommu_mode = VFIO_TYPE1_IOMMU;
+    }
+
+
+  pool_get (lvm->iommu_groups, g);
+  g->fd = fd;
+  g->refcnt = 1;
+  hash_set (lvm->iommu_pool_index_by_group, group, g - lvm->iommu_groups);
+  vec_free (s);
+  return 0;
+error:
+  close (fd);
+  return err;
+}
+
+clib_error_t *
+linux_vfio_group_get_device_fd (vlib_pci_addr_t * addr, int *fdp)
+{
+  clib_error_t *err = 0;
+  linux_pci_vfio_iommu_group_t *g;
+  u8 *s = 0;
+  int iommu_group;
+  u8 *tmpstr;
+  int fd;
+
+  s = format (s, "/sys/bus/pci/devices/%U/iommu_group", format_vlib_pci_addr,
+	      addr);
+  tmpstr = clib_sysfs_link_to_name ((char *) s);
+  if (tmpstr)
+    {
+      iommu_group = atoi ((char *) tmpstr);
+      vec_free (tmpstr);
+    }
+  else
+    {
+      err = clib_error_return (0, "Cannot find IOMMU group for PCI device ",
+			       "'%U'", format_vlib_pci_addr, addr);
+      goto error;
+    }
+  vec_reset_length (s);
+
+  if ((err = open_vfio_iommu_group (iommu_group)))
+    return err;
+
+  g = get_vfio_iommu_group (iommu_group);
+
+  s = format (s, "%U%c", format_vlib_pci_addr, addr, 0);
+  if ((fd = ioctl (g->fd, VFIO_GROUP_GET_DEVICE_FD, (char *) s)) < 0)
+    {
+      err = clib_error_return_unix (0, "ioctl(VFIO_GROUP_GET_DEVICE_FD) '%U'",
+				    format_vlib_pci_addr, addr);
+      goto error;
+    }
+  vec_reset_length (s);
+
+  *fdp = fd;
+
+error:
+  vec_free (s);
+  return err;
+}
+
+clib_error_t *
+linux_vfio_init (vlib_main_t * vm)
+{
+  linux_vfio_main_t *lvm = &vfio_main;
+  int fd;
+
+  lvm->ext_container_fd = -1;
+
+  fd = open ("/dev/vfio/vfio", O_RDWR);
+
+  /* check if iommu is available */
+  if (fd != -1)
+    {
+      if (ioctl (fd, VFIO_GET_API_VERSION) != VFIO_API_VERSION)
+	{
+	  close (fd);
+	  fd = -1;
+	}
+      else if (ioctl (fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) == 1)
+	lvm->flags |= LINUX_VFIO_F_HAVE_IOMMU;
+    }
+
+  lvm->iommu_pool_index_by_group = hash_create (0, sizeof (uword));
+  lvm->container_fd = fd;
+  return 0;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vlib/linux/vfio.h b/src/vlib/linux/vfio.h
new file mode 100644
index 00000000000..8e0758cf2e4
--- /dev/null
+++ b/src/vlib/linux/vfio.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef included_vlib_linux_vfio_h
+#define included_vlib_linux_vfio_h
+
+typedef struct
+{
+  int group;
+  int fd;
+  int refcnt;
+} linux_pci_vfio_iommu_group_t;
+
+typedef struct
+{
+  u32 flags;
+#define LINUX_VFIO_F_HAVE_IOMMU		(1 << 0)
+  int container_fd;
+  int ext_container_fd;		/* container fd used by external library, i.e DPDK */
+
+  /* VFIO */
+  int iommu_mode;
+
+  /* pool of IOMMU groups */
+  linux_pci_vfio_iommu_group_t *iommu_groups;
+
+  /* iommu group pool index by group id  hash */
+  uword *iommu_pool_index_by_group;
+
+} linux_vfio_main_t;
+
+extern linux_vfio_main_t vfio_main;
+
+clib_error_t *linux_vfio_init (vlib_main_t * vm);
+void linux_vfio_dma_map_regions (vlib_main_t * vm);
+clib_error_t *linux_vfio_group_get_device_fd (vlib_pci_addr_t * addr,
+					      int *fd);
+
+
+#endif /* included_vlib_linux_vfio_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */