qemu/qemu.git/migration, branch master

monitor: move HMP-specific to monitor-hmp-internal.h

2026-08-29T08:07:45+00:00

Move HMP-specific declarations to its own CONFIG_HMP guarded header. Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Marc-André Lureau Message-ID: <20260828-qemu-no-hmp-v5-48-9227de146347@redhat.com>

build-sys: make HMP source files conditional on have_hmp

2026-08-29T08:07:45+00:00

Exclude all *-hmp-cmds.c files and HMP-only source files from the build when HMP is disabled. Also conditionalise the hmp-commands.hx header generation and the test-hmp qtest. Acked-by: Dr. David Alan Gilbert Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Marc-André Lureau Message-ID: <20260828-qemu-no-hmp-v5-45-9227de146347@redhat.com>

Guard HMP command implementations with CONFIG_HMP

2026-08-29T08:07:45+00:00

Add #ifdef CONFIG_HMP around all hmp_* function implementations and their HMP-only helpers across subsystems. This covers monitor_register_hmp* callers, hmp_info_* handlers, and HMP-only helper functions like slirp_lookup. To link succesfully, use empty cmds tables in hmp-cmds.c (to be removed once meson build-sys is updated with !hmp support later in the series) Reviewed-by: Jason J. Herne Reviewed-by: Daniel P. Berrangé Signed-off-by: Marc-André Lureau Message-ID: <20260828-qemu-no-hmp-v5-41-9227de146347@redhat.com>

monitor: tighten monitor_printf*()

2026-08-29T08:07:45+00:00

Rename monitor_printf->monitor_hmp_printf, monitor_vprintf-> monitor_hmp_vprintf, and monitor_printc->monitor_hmp_printc, changing the first parameter from Monitor * to MonitorHMP * to enforce type safety. The implementation is also simplified: monitor_hmp_vprintf now directly calls g_strdup_vprintf + monitor_puts, removing the virtual dispatch via moncls->vprintf. The dev_print() callbacks are temporarily using the MONITOR_HMP(mon) cast, they are fixed in the following commits. Early return in qemu_vprintf() if "hmp" is NULL, relying on monitor_hmp_vprintf() handling NULL case is a bit uncommon. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Marc-André Lureau Message-ID: <20260828-qemu-no-hmp-v5-37-9227de146347@redhat.com>

monitor: make hmp_handle_error() take MonitorHMP

2026-08-29T08:07:44+00:00

Mostly mechanical, with a few adjustments around it. Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Daniel P. Berrangé Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Marc-André Lureau Message-ID: <20260828-qemu-no-hmp-v5-32-9227de146347@redhat.com>

monitor: change HMPCommand cmd to take MonitorHMP

2026-08-29T08:07:44+00:00

HMP commands are specific to the HMP monitor, so make the cmd function pointer in HMPCommand take MonitorHMP * instead of Monitor *. This strengthens type safety and makes the HMP-specific nature of these handlers explicit. Handler functions are renamed to take MonitorHMP *hmp, with a local Monitor *mon = MONITOR(hmp) added where the body needs the base type. Following patches will drop it, since most functions are HMP specific. Reviewed-by: Daniel P. Berrangé Reviewed-by: Jason J. Herne Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Marc-André Lureau Message-ID: <20260828-qemu-no-hmp-v5-31-9227de146347@redhat.com>

migration/postcopy: fix page_requested leak for vhost-user shared pages

2026-08-28T12:09:32+00:00

With postcopy-preempt enabled, a postcopy migration of a guest with a vhost-user device can hang at the very end on the destination, after all pages are transferred (query-migrate: status=postcopy-active, remaining=0). Root cause is an add/del key mismatch on mis->page_requested: - add: a backend fault goes through postcopy_request_shared_page() -> postcopy_request_page() -> migrate_send_rp_req_pages(), which inserts the request and bumps page_requested_count keyed by client_addr. - del: qemu_ufd_copy_ioctl() removes the entry and drops the counter keyed by this QEMU process's host address for the page. client_addr is a VA in the external vhost-user backend's address space and never equals QEMU's host address, so the removal misses and the counter leaks. postcopy_ram_incoming_cleanup() then waits for it to reach zero forever, which also stalls the source (it waits for the return path). Racing threads: dst: postcopy_ram_listen_thread -> postcopy_ram_incoming_cleanup -> qemu_cond_wait_impl (waits for page_requested_count==0) (postcopy_preempt_thread already placed/woke the pages) src: migration_thread -> migration_completion -> await_return_path_close_on_source -> qemu_thread_join (source_return_path_thread blocked in recvmsg) The leak is only triggered when the vhost-user backend faults on a page that has not been received yet: only then does the request take the shared-fault slow path and register an entry in page_requested. If that page is subsequently delivered while the request is still outstanding, its entry is never removed. (Pages already present when the backend faults just take the wake path and never register.) So a run may leak only a few entries (9 of ~244k requests in our repro) yet still hang. Fix: key the request with the same host address the removal uses (rb->host + aligned_rbo) instead of client_addr. The backend wake still happens at placement time via postcopy_wake_shared(). Signed-off-by: hongmianquan Reviewed-by: Peter Xu Signed-off-by: Fabiano Rosas

migration: Harden vmstate_size

2026-08-28T12:09:32+00:00

Protect vmstate_size against overflow of the on-stack 64bit integer during multiplication. The data at size_indirect.offset comes from the migration stream. Acked-by: Peter Xu Signed-off-by: Fabiano Rosas

migration: Harden vmstate_handle_alloc

2026-08-28T12:09:32+00:00

Harden the vmstate_handle_alloc function against overflow of the 64bit integers it consumes and failure to allocate due to an exceedingly large request. Acked-by: Peter Xu Signed-off-by: Fabiano Rosas

migration: Check more vmstate flags

2026-08-28T12:09:31+00:00

Add more checks for vmstate flags constraints. Acked-by: Peter Xu Signed-off-by: Fabiano Rosas