diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | block/block-ram-registrar.c | 58 | ||||
| -rw-r--r-- | block/meson.build | 1 | ||||
| -rw-r--r-- | include/sysemu/block-ram-registrar.h | 37 |
4 files changed, 97 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 8b4363c0ff..cda146ebbb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2510,6 +2510,7 @@ F: block* F: block/ F: hw/block/ F: include/block/ +F: include/sysemu/block-*.h F: qemu-img* F: docs/tools/qemu-img.rst F: qemu-io* diff --git a/block/block-ram-registrar.c b/block/block-ram-registrar.c new file mode 100644 index 0000000000..25dbafa789 --- /dev/null +++ b/block/block-ram-registrar.c @@ -0,0 +1,58 @@ +/* + * BlockBackend RAM Registrar + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "sysemu/block-backend.h" +#include "sysemu/block-ram-registrar.h" +#include "qapi/error.h" + +static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size, + size_t max_size) +{ + BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier); + Error *err = NULL; + + if (!r->ok) { + return; /* don't try again if we've already failed */ + } + + if (!blk_register_buf(r->blk, host, max_size, &err)) { + error_report_err(err); + ram_block_notifier_remove(&r->notifier); + r->ok = false; + } +} + +static void ram_block_removed(RAMBlockNotifier *n, void *host, size_t size, + size_t max_size) +{ + BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier); + blk_unregister_buf(r->blk, host, max_size); +} + +void blk_ram_registrar_init(BlockRAMRegistrar *r, BlockBackend *blk) +{ + r->blk = blk; + r->notifier = (RAMBlockNotifier){ + .ram_block_added = ram_block_added, + .ram_block_removed = ram_block_removed, + + /* + * .ram_block_resized() is not necessary because we use the max_size + * value that does not change across resize. + */ + }; + r->ok = true; + + ram_block_notifier_add(&r->notifier); +} + +void blk_ram_registrar_destroy(BlockRAMRegistrar *r) +{ + if (r->ok) { + ram_block_notifier_remove(&r->notifier); + } +} diff --git a/block/meson.build b/block/meson.build index 500878f082..b7c68b83a3 100644 --- a/block/meson.build +++ b/block/meson.build @@ -46,6 +46,7 @@ block_ss.add(files( ), zstd, zlib, gnutls) softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('blkreplay.c')) +softmmu_ss.add(files('block-ram-registrar.c')) if get_option('qcow1').allowed() block_ss.add(files('qcow.c')) diff --git a/include/sysemu/block-ram-registrar.h b/include/sysemu/block-ram-registrar.h new file mode 100644 index 0000000000..d8b2f7942b --- /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 */ |