[Qemu-devel] [PATCH v2 07/12] Rework ram_control_load_hook to hook during block load

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

We need the names of RAMBlocks as they're loaded for RDMA,
reuse a slightly modified ram_control_load_hook:
  a) Pass a 'data' parameter to use for the name in the block-reg
     case
  b) Only some hook types now require the presence of a hook function.

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
 arch_init.c                   |  4 +++-
 include/migration/migration.h |  2 +-
 include/migration/qemu-file.h | 14 +++++++++-----
 migration/qemu-file.c         | 16 +++++++++++-----
 migration/rdma.c              | 28 ++++++++++++++++++++++------
 trace-events                  |  2 +-
 6 files changed, 47 insertions(+), 19 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index d294474..dc9cc7e 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -1569,6 +1569,8 @@ static int ram_load(QEMUFile *f, void *opaque, int 
version_id)
                                 error_report_err(local_err);
                             }
                         }
+                        ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
+                                              block->idstr);
                         break;
                     }
                 }
@@ -1637,7 +1639,7 @@ static int ram_load(QEMUFile *f, void *opaque, int 
version_id)
             break;
         default:
             if (flags & RAM_SAVE_FLAG_HOOK) {
-                ram_control_load_hook(f, flags);
+                ram_control_load_hook(f, RAM_CONTROL_HOOK, NULL);
             } else {
                 error_report("Unknown combination of migration flags: %#x",
                              flags);
diff --git a/include/migration/migration.h b/include/migration/migration.h
index a6e025a..096e1ea 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -164,7 +164,7 @@ int migrate_decompress_threads(void);
 
 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
-void ram_control_load_hook(QEMUFile *f, uint64_t flags);
+void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 
 /* Whenever this is found in the data stream, the flags
  * will be passed to ram_control_load_hook in the incoming-migration
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index a01c5b8..7aafe19 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -63,16 +63,20 @@ typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, 
struct iovec *iov,
 /*
  * This function provides hooks around different
  * stages of RAM migration.
+ * 'opaque' is the backend specific data in QEMUFile
+ * 'data' is call specific data associated with the 'flags' value
  */
-typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags);
+typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
+                              void *data);
 
 /*
  * Constants used by ram_control_* hooks
  */
-#define RAM_CONTROL_SETUP    0
-#define RAM_CONTROL_ROUND    1
-#define RAM_CONTROL_HOOK     2
-#define RAM_CONTROL_FINISH   3
+#define RAM_CONTROL_SETUP     0
+#define RAM_CONTROL_ROUND     1
+#define RAM_CONTROL_HOOK      2
+#define RAM_CONTROL_FINISH    3
+#define RAM_CONTROL_BLOCK_REG 4
 
 /*
  * This function allows override of where the RAM page
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 2750365..5493977 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -128,7 +128,7 @@ void ram_control_before_iterate(QEMUFile *f, uint64_t flags)
     int ret = 0;
 
     if (f->ops->before_ram_iterate) {
-        ret = f->ops->before_ram_iterate(f, f->opaque, flags);
+        ret = f->ops->before_ram_iterate(f, f->opaque, flags, NULL);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
         }
@@ -140,24 +140,30 @@ void ram_control_after_iterate(QEMUFile *f, uint64_t 
flags)
     int ret = 0;
 
     if (f->ops->after_ram_iterate) {
-        ret = f->ops->after_ram_iterate(f, f->opaque, flags);
+        ret = f->ops->after_ram_iterate(f, f->opaque, flags, NULL);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
         }
     }
 }
 
-void ram_control_load_hook(QEMUFile *f, uint64_t flags)
+void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data)
 {
     int ret = -EINVAL;
 
     if (f->ops->hook_ram_load) {
-        ret = f->ops->hook_ram_load(f, f->opaque, flags);
+        ret = f->ops->hook_ram_load(f, f->opaque, flags, data);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
         }
     } else {
-        qemu_file_set_error(f, ret);
+        /*
+         * Hook is a hook specifically requested by the source sending a flag
+         * that expects there to be a hook on the destination.
+         */
+        if (flags == RAM_CONTROL_HOOK) {
+            qemu_file_set_error(f, ret);
+        }
     }
 }
 
diff --git a/migration/rdma.c b/migration/rdma.c
index cb66721..396329c 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -2905,8 +2905,7 @@ err_rdma_dest_wait:
  *
  * Keep doing this until the source tells us to stop.
  */
-static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque,
-                                         uint64_t flags)
+static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque)
 {
     RDMAControlHeader reg_resp = { .len = sizeof(RDMARegisterResult),
                                .type = RDMA_CONTROL_REGISTER_RESULT,
@@ -2936,7 +2935,7 @@ static int qemu_rdma_registration_handle(QEMUFile *f, 
void *opaque,
     CHECK_ERROR_STATE();
 
     do {
-        trace_qemu_rdma_registration_handle_wait(flags);
+        trace_qemu_rdma_registration_handle_wait();
 
         ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_NONE);
 
@@ -3124,8 +3123,25 @@ out:
     return ret;
 }
 
+static int rdma_load_hook(QEMUFile *f, void *opaque, uint64_t flags, void 
*data)
+{
+    switch (flags) {
+    case RAM_CONTROL_BLOCK_REG:
+        /* TODO A later patch */
+        return 0;
+        break;
+
+    case RAM_CONTROL_HOOK:
+        return qemu_rdma_registration_handle(f, opaque);
+
+    default:
+        /* Shouldn't be called with any other values */
+        abort();
+    }
+}
+
 static int qemu_rdma_registration_start(QEMUFile *f, void *opaque,
-                                        uint64_t flags)
+                                        uint64_t flags, void *data)
 {
     QEMUFileRDMA *rfile = opaque;
     RDMAContext *rdma = rfile->rdma;
@@ -3144,7 +3160,7 @@ static int qemu_rdma_registration_start(QEMUFile *f, void 
*opaque,
  * First, flush writes, if any.
  */
 static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
-                                       uint64_t flags)
+                                       uint64_t flags, void *data)
 {
     Error *local_err = NULL, **errp = &local_err;
     QEMUFileRDMA *rfile = opaque;
@@ -3266,7 +3282,7 @@ static const QEMUFileOps rdma_read_ops = {
     .get_buffer    = qemu_rdma_get_buffer,
     .get_fd        = qemu_rdma_get_fd,
     .close         = qemu_rdma_close,
-    .hook_ram_load = qemu_rdma_registration_handle,
+    .hook_ram_load = rdma_load_hook,
 };
 
 static const QEMUFileOps rdma_write_ops = {
diff --git a/trace-events b/trace-events
index 557770c..0f37a4b 100644
--- a/trace-events
+++ b/trace-events
@@ -1432,7 +1432,7 @@ qemu_rdma_registration_handle_register_rkey(int rkey) "%x"
 qemu_rdma_registration_handle_unregister(int requests) "%d requests"
 qemu_rdma_registration_handle_unregister_loop(int count, int index, uint64_t 
chunk) "Unregistration request (%d): index %d, chunk %" PRIu64
 qemu_rdma_registration_handle_unregister_success(uint64_t chunk) "%" PRIu64
-qemu_rdma_registration_handle_wait(uint64_t flags) "Waiting for next request 
%" PRIu64
+qemu_rdma_registration_handle_wait(void) ""
 qemu_rdma_registration_start(uint64_t flags) "%" PRIu64
 qemu_rdma_registration_stop(uint64_t flags) "%" PRIu64
 qemu_rdma_registration_stop_ram(void) ""
-- 
2.4.2