Merge tag 'block-pull-request' of https://gitlab.com/stefanha/qemu into staging

Pull request

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# gpg: Signature made Wed 26 Oct 2022 14:58:38 EDT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [ultimate]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [ultimate]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* tag 'block-pull-request' of https://gitlab.com/stefanha/qemu:
  virtio-blk: use BDRV_REQ_REGISTERED_BUF optimization hint
  blkio: implement BDRV_REQ_REGISTERED_BUF optimization
  stubs: add qemu_ram_block_from_host() and qemu_ram_get_fd()
  exec/cpu-common: add qemu_ram_get_fd()
  block: add BlockRAMRegistrar
  numa: use QLIST_FOREACH_SAFE() for RAM block notifiers
  block: return errors from bdrv_register_buf()
  block: add BDRV_REQ_REGISTERED_BUF request flag
  block: use BdrvRequestFlags type for supported flag fields
  block: pass size to bdrv_unregister_buf()
  numa: call ->ram_block_removed() in ram_block_notifer_remove()
  blkio: add libblkio block driver
  coroutine: add flag to re-queue at front of CoQueue

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

2 files changed, 39 insertions, 2 deletions

diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h
index 415f0c9..6858e39 100644
--- a/include/sysemu/block-backend-global-state.h
+++ b/include/sysemu/block-backend-global-state.h
@@ -106,8 +106,8 @@ void blk_io_limits_enable(BlockBackend *blk, const char *group);
 void blk_io_limits_update_group(BlockBackend *blk, const char *group);
 void blk_set_force_allow_inactivate(BlockBackend *blk);
 
-void blk_register_buf(BlockBackend *blk, void *host, size_t size);
-void blk_unregister_buf(BlockBackend *blk, void *host);
+bool blk_register_buf(BlockBackend *blk, void *host, size_t size, Error **errp);
+void blk_unregister_buf(BlockBackend *blk, void *host, size_t size);
 
 const BdrvChild *blk_root(BlockBackend *blk);
 
diff --git a/include/sysemu/block-ram-registrar.h b/include/sysemu/block-ram-registrar.h
new file mode 100644
index 0000000..d8b2f79
--- /dev/null
+++ b/include/sysemu/block-ram-registrar.h
@@ -0,0 +1,37 @@
+/*
+ * BlockBackend RAM Registrar
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef BLOCK_RAM_REGISTRAR_H
+#define BLOCK_RAM_REGISTRAR_H
+
+#include "exec/ramlist.h"
+
+/**
+ * struct BlockRAMRegistrar:
+ *
+ * Keeps RAMBlock memory registered with a BlockBackend using
+ * blk_register_buf() including hotplugged memory.
+ *
+ * Emulated devices or other BlockBackend users initialize a BlockRAMRegistrar
+ * with blk_ram_registrar_init() before submitting I/O requests with the
+ * BDRV_REQ_REGISTERED_BUF flag set.
+ */
+typedef struct {
+    BlockBackend *blk;
+    RAMBlockNotifier notifier;
+    bool ok;
+} BlockRAMRegistrar;
+
+void blk_ram_registrar_init(BlockRAMRegistrar *r, BlockBackend *blk);
+void blk_ram_registrar_destroy(BlockRAMRegistrar *r);
+
+/* Have all RAMBlocks been registered successfully? */
+static inline bool blk_ram_registrar_ok(BlockRAMRegistrar *r)
+{
+    return r->ok;
+}
+
+#endif /* BLOCK_RAM_REGISTRAR_H */