This patch series tries to introduce a mechanism using side channel pipe for RAM via SCM_RIGHTS with unix domain socket protocol migration.
This side channel is used for the page flipping by vmsplice, which is the internal mechanism for localhost migration that we are trying to add to QEMU. The backgroud info and previous patch series for reference, Localhost migration http://lists.nongnu.org/archive/html/qemu-devel/2013-08/msg02916.html migration: Introduce side channel for RAM http://lists.gnu.org/archive/html/qemu-devel/2013-09/msg04043.html I have picked patches from the localhost migration series and rebased it on the series of side channel, now it is a complete series that passed the basic test. Please let me know if there is anything needs to be fixed or improved. Your suggestions and comments are very welcome, and thanks to Paolo for his continued review and useful suggestions. Changes since V3: Address comments from Paolo including: - Get rid of useless check in send_pipefd() and the override of before_ram_iterate, send pipefd in the first save_page call, qemu_get_byte() in the first ram_load correspondingly. - Add new argument ram_addr_t to hook_ram_load to cut half of the data transferred on the socket. - Add transition from 'debug' to 'memory-stale'. - Other minor fixes. Changes since V2: Address comments from Paolo including: - Doc improvement for QAPI. - Use callback get_buffer as the only one receiver. - Rename the new RunState flipping-migrate to memory-stale, and add transition from 'prelaunch' to 'memory-stale'. - Other minor fixes. Changes since V1: Address suggestions from Paolo Bonzini including: - Use Unix socket QEMUFile as basis of code and adjust the way of overriding RDMA hooks. - Involve the vmsplice for page flipping. - Add new RunState RUN_STATE_FLIPPING_MIGRATE and add it to runstate_needs_reset() for the adjustment of the current migration process with page flipping. Lei Li (17): QAPI: introduce magration capability unix_page_flipping migration: add migrate_unix_page_flipping() qmp-command.hx: add missing docs for migration capabilites migration-local: add QEMUFileLocal with socket based QEMUFile migration-local: introduce qemu_fopen_socket_local() migration-local: add send_pipefd() save_page: replace block_offset with a MemoryRegion migration-local: override save_page for page transmit savevm: adjust ram_control_save_page with page flipping add unix_msgfd_lookup() to callback get_buffer add argument ram_addr_t to hook_ram_load migration-local: override hook_ram_load migration-unix: replace qemu_fopen_socket with qemu_fopen_socket_local add new RanState RAN_STATE_MEMORY_STALE migration-unix: page flipping support on unix outgoing migration: adjust migration_thread() process for unix_page_flipping hmp: better fomat for info migrate_capabilities Makefile.target | 1 + arch_init.c | 4 +- migration-local.c | 512 ++++++++++++++++++++++++++++++++++++++++++ hmp.c | 5 +- include/migration/migration.h | 3 + include/migration/qemu-file.h | 2 + migration-unix.c | 27 ++- migration-rdma.c | 4 +- migration.c | 18 +- qapi-schema.json | 18 +- qmp-commands.hx | 8 + savevm.c | 21 +- vl.c | 12 +- 13 files changed, 617 insertions(+), 27 deletions(-) create mode 100644 migration-local.c