ssvm: reuse clib mem infra for memfd segments

[vpp.git] / src / svm / ssvm.c

diff --git a/src/svm/ssvm.c b/src/svm/ssvm.c
index 6f409eb..36abc20 100644 (file)
--- a/src/svm/ssvm.c
+++ b/src/svm/ssvm.c
@@ -12,11 +12,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-#include "ssvm.h"
+#include <svm/ssvm.h>
+#include <svm/svm_common.h>
 
 int
 ssvm_master_init (ssvm_private_t * ssvm, u32 master_index)
 {
+  svm_main_region_t *smr = svm_get_root_rp ()->data_base;
   int ssvm_fd;
   u8 *ssvm_filename;
   u8 junk = 0;
@@ -29,6 +31,10 @@ ssvm_master_init (ssvm_private_t * ssvm, u32 master_index)
   if (ssvm->ssvm_size == 0)
     return SSVM_API_ERROR_NO_SIZE;
 
+  if (CLIB_DEBUG > 1)
+    clib_warning ("[%d] creating segment '%s'", getpid (), ssvm->name);
+
+  ASSERT (vec_c_string_is_terminated (ssvm->name));
   ssvm_filename = format (0, "/dev/shm/%s%c", ssvm->name, 0);
 
   unlink ((char *) ssvm_filename);
@@ -43,6 +49,11 @@ ssvm_master_init (ssvm_private_t * ssvm, u32 master_index)
       return SSVM_API_ERROR_CREATE_FAILURE;
     }
 
+  if (fchmod (ssvm_fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) < 0)
+    clib_unix_warning ("ssvm segment chmod");
+  if (fchown (ssvm_fd, smr->uid, smr->gid) < 0)
+    clib_unix_warning ("ssvm segment chown");
+
   if (lseek (ssvm_fd, ssvm->ssvm_size, SEEK_SET) < 0)
     {
       clib_unix_warning ("lseek");
@@ -107,6 +118,7 @@ ssvm_slave_init (ssvm_private_t * ssvm, int timeout_in_seconds)
   int ssvm_fd = -1;
   ssvm_shared_header_t *sh;
 
+  ASSERT (vec_c_string_is_terminated (ssvm->name));
   ssvm->i_am_master = 0;
 
   while (timeout_in_seconds-- > 0)
@@ -169,6 +181,139 @@ re_map_it:
   return 0;
 }
 
+void
+ssvm_delete (ssvm_private_t * ssvm)
+{
+  u8 *fn;
+
+  fn = format (0, "/dev/shm/%s%c", ssvm->name, 0);
+
+  if (CLIB_DEBUG > 1)
+    clib_warning ("[%d] unlinking ssvm (%s) backing file '%s'", getpid (),
+                 ssvm->name, fn);
+
+  /* Throw away the backing file */
+  if (unlink ((char *) fn) < 0)
+    clib_unix_warning ("unlink segment '%s'", ssvm->name);
+
+  vec_free (fn);
+  vec_free (ssvm->name);
+
+  munmap ((void *) ssvm->requested_va, ssvm->ssvm_size);
+}
+
+int
+ssvm_master_init_memfd (ssvm_private_t * memfd, u32 master_index)
+{
+  uword page_size, flags = MHEAP_FLAG_DISABLE_VM | MHEAP_FLAG_THREAD_SAFE;
+  ssvm_shared_header_t *sh;
+  void *oldheap;
+  clib_mem_vm_alloc_t alloc = { 0 };
+  clib_error_t *err;
+
+  if (memfd->ssvm_size == 0)
+    return SSVM_API_ERROR_NO_SIZE;
+
+  ASSERT (vec_c_string_is_terminated (memfd->name));
+  memfd->name = format (0, "memfd svm region %d%c", master_index, 0);
+
+  alloc.name = (char *) memfd->name;
+  alloc.size = memfd->ssvm_size;
+  alloc.flags = CLIB_MEM_VM_F_SHARED;
+  if ((err = clib_mem_vm_ext_alloc (&alloc)))
+    {
+      clib_error_report (err);
+      return SSVM_API_ERROR_CREATE_FAILURE;
+    }
+
+  memfd->fd = alloc.fd;
+  memfd->sh = alloc.addr;
+  memfd->my_pid = getpid ();
+  memfd->i_am_master = 1;
+
+  page_size = 1 << alloc.log2_page_size;
+  sh = (ssvm_shared_header_t *) memfd->sh;
+  sh->master_pid = memfd->my_pid;
+  sh->ssvm_size = memfd->ssvm_size;
+  sh->heap = mheap_alloc_with_flags (((u8 *) sh) + page_size,
+                                    memfd->ssvm_size - page_size, flags);
+  sh->ssvm_va = pointer_to_uword (sh);
+  sh->master_index = master_index;
+
+  oldheap = ssvm_push_heap (sh);
+  sh->name = format (0, "%s%c", memfd->name, 0);
+  ssvm_pop_heap (oldheap);
+
+  /* The application has to set set sh->ready... */
+  return 0;
+}
+
+/*
+ * Subtly different than svm_slave_init. The caller
+ * needs to acquire a usable file descriptor for the memfd segment
+ * e.g. via vppinfra/socket.c:default_socket_recvmsg
+ */
+
+int
+ssvm_slave_init_memfd (ssvm_private_t * memfd)
+{
+  clib_mem_vm_map_t mapa = { 0 };
+  ssvm_shared_header_t *sh;
+  uword page_size;
+
+  memfd->i_am_master = 0;
+
+  page_size = clib_mem_vm_get_page_size (memfd->fd);
+  if (!page_size)
+    {
+      clib_unix_warning ("page size unknown");
+      return SSVM_API_ERROR_MMAP;
+    }
+
+  /*
+   * Map the segment once, to look at the shared header
+   */
+  mapa.fd = memfd->fd;
+  mapa.size = page_size;
+
+  if (clib_mem_vm_ext_map (&mapa))
+    {
+      clib_unix_warning ("slave research mmap");
+      close (memfd->fd);
+      return SSVM_API_ERROR_MMAP;
+    }
+
+  sh = mapa.addr;
+  memfd->requested_va = sh->ssvm_va;
+  memfd->ssvm_size = sh->ssvm_size;
+  munmap (sh, page_size);
+
+  /*
+   * Remap the segment at the 'right' address
+   */
+  mapa.requested_va = memfd->requested_va;
+  mapa.size = memfd->ssvm_size;
+  if (clib_mem_vm_ext_map (&mapa))
+    {
+      clib_unix_warning ("slave final mmap");
+      close (memfd->fd);
+      return SSVM_API_ERROR_MMAP;
+    }
+
+  sh = mapa.addr;
+  sh->slave_pid = getpid ();
+  memfd->sh = sh;
+  return 0;
+}
+
+void
+ssvm_delete_memfd (ssvm_private_t * memfd)
+{
+  vec_free (memfd->name);
+  clib_mem_vm_free (memfd->sh, memfd->ssvm_size);
+  close (memfd->fd);
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *