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

Migration/Memory Pull for 10.2

- PeterX's fix on tls warning for preempt channel when migratino completes
- Arun's series to enhance error reporting for vTPM and migration framework
- PeterX's patch to cleanup multifd send TLS BYE messages
- Juraj's fix on postcopy start state transition when switchover failed
- Yanfei's fix to migrate APIC before VFIO-PCI to avoid irq fallbacks
- Dan's cleanup to simplify error reporting in qemu_fill_buffer()
- PeterM's fix on address space leak when cpu hot plug / unplug
- Steve's cpr-exec wholeset

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# gpg:                using EDDSA key B9184DC20CC457DACF7DD1A93B5FCCCDF3ABD706
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# gpg: Good signature from "Peter Xu <xzpeter@gmail.com>" [unknown]
# gpg:                 aka "Peter Xu <peterx@redhat.com>" [unknown]
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* tag 'staging-pull-request' of https://gitlab.com/peterx/qemu: (45 commits)
  migration-test: test cpr-exec
  vfio: cpr-exec mode
  migration: cpr-exec docs
  migration: cpr-exec mode
  migration: cpr-exec save and load
  migration: cpr-exec-command parameter
  oslib: qemu_clear_cloexec
  migration: add cpr_walk_fd
  migration: multi-mode notifier
  migration: simplify error reporting after channel read
  physmem: Destroy all CPU AddressSpaces on unrealize
  memory: New AS helper to serialize destroy+free
  include/system/memory.h: Clarify address_space_destroy() behaviour
  migration: ensure APIC is loaded prior to VFIO PCI devices
  migration: Fix state transition in postcopy_start() error handling
  migration/multifd/tls: Cleanup BYE message processing on sender side
  migration: HMP: Adjust the order of output fields
  migration: Make migration_has_failed() work even for CANCELLING
  io/crypto: Move tls premature termination handling into QIO layer
  backends/tpm: Propagate vTPM error on migration failure
  ...

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 194 insertions, 0 deletions

diff --git a/migration/cpr-exec.c b/migration/cpr-exec.c
new file mode 100644
index 0000000000..d57714bc5d
--- /dev/null
+++ b/migration/cpr-exec.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (c) 2021-2025 Oracle and/or its affiliates.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "qemu/memfd.h"
+#include "qapi/error.h"
+#include "qapi/type-helpers.h"
+#include "io/channel-file.h"
+#include "io/channel-socket.h"
+#include "block/block-global-state.h"
+#include "qemu/main-loop.h"
+#include "migration/cpr.h"
+#include "migration/qemu-file.h"
+#include "migration/migration.h"
+#include "migration/misc.h"
+#include "migration/vmstate.h"
+#include "system/runstate.h"
+#include "trace.h"
+
+#define CPR_EXEC_STATE_NAME "QEMU_CPR_EXEC_STATE"
+
+static QEMUFile *qemu_file_new_fd_input(int fd, const char *name)
+{
+    g_autoptr(QIOChannelFile) fioc = qio_channel_file_new_fd(fd);
+    QIOChannel *ioc = QIO_CHANNEL(fioc);
+    qio_channel_set_name(ioc, name);
+    return qemu_file_new_input(ioc);
+}
+
+static QEMUFile *qemu_file_new_fd_output(int fd, const char *name)
+{
+    g_autoptr(QIOChannelFile) fioc = qio_channel_file_new_fd(fd);
+    QIOChannel *ioc = QIO_CHANNEL(fioc);
+    qio_channel_set_name(ioc, name);
+    return qemu_file_new_output(ioc);
+}
+
+void cpr_exec_persist_state(QEMUFile *f)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(qemu_file_get_ioc(f));
+    int mfd = dup(fioc->fd);
+    char val[16];
+
+    /* Remember mfd in environment for post-exec load */
+    qemu_clear_cloexec(mfd);
+    snprintf(val, sizeof(val), "%d", mfd);
+    g_setenv(CPR_EXEC_STATE_NAME, val, 1);
+}
+
+static int cpr_exec_find_state(void)
+{
+    const char *val = g_getenv(CPR_EXEC_STATE_NAME);
+    int mfd;
+
+    assert(val);
+    g_unsetenv(CPR_EXEC_STATE_NAME);
+    assert(!qemu_strtoi(val, NULL, 10, &mfd));
+    return mfd;
+}
+
+bool cpr_exec_has_state(void)
+{
+    return g_getenv(CPR_EXEC_STATE_NAME) != NULL;
+}
+
+void cpr_exec_unpersist_state(void)
+{
+    int mfd;
+    const char *val = g_getenv(CPR_EXEC_STATE_NAME);
+
+    g_unsetenv(CPR_EXEC_STATE_NAME);
+    assert(val);
+    assert(!qemu_strtoi(val, NULL, 10, &mfd));
+    close(mfd);
+}
+
+QEMUFile *cpr_exec_output(Error **errp)
+{
+    int mfd;
+
+#ifdef CONFIG_LINUX
+    mfd = qemu_memfd_create(CPR_EXEC_STATE_NAME, 0, false, 0, 0, errp);
+#else
+    mfd = -1;
+#endif
+
+    if (mfd < 0) {
+        return NULL;
+    }
+
+    return qemu_file_new_fd_output(mfd, CPR_EXEC_STATE_NAME);
+}
+
+QEMUFile *cpr_exec_input(Error **errp)
+{
+    int mfd = cpr_exec_find_state();
+
+    lseek(mfd, 0, SEEK_SET);
+    return qemu_file_new_fd_input(mfd, CPR_EXEC_STATE_NAME);
+}
+
+static bool preserve_fd(int fd)
+{
+    qemu_clear_cloexec(fd);
+    return true;
+}
+
+static bool unpreserve_fd(int fd)
+{
+    qemu_set_cloexec(fd);
+    return true;
+}
+
+static void cpr_exec_preserve_fds(void)
+{
+    cpr_walk_fd(preserve_fd);
+}
+
+void cpr_exec_unpreserve_fds(void)
+{
+    cpr_walk_fd(unpreserve_fd);
+}
+
+static void cpr_exec_cb(void *opaque)
+{
+    MigrationState *s = migrate_get_current();
+    char **argv = strv_from_str_list(s->parameters.cpr_exec_command);
+    Error *err = NULL;
+
+    /*
+     * Clear the close-on-exec flag for all preserved fd's.  We cannot do so
+     * earlier because they should not persist across miscellaneous fork and
+     * exec calls that are performed during normal operation.
+     */
+    cpr_exec_preserve_fds();
+
+    trace_cpr_exec();
+    execvp(argv[0], argv);
+
+    /*
+     * exec should only fail if argv[0] is bogus, or has a permissions problem,
+     * or the system is very short on resources.
+     */
+    g_strfreev(argv);
+    cpr_exec_unpreserve_fds();
+
+    error_setg_errno(&err, errno, "execvp %s failed", argv[0]);
+    error_report_err(error_copy(err));
+    migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
+    migrate_set_error(s, err);
+
+    /* Note, we can go from state COMPLETED to FAILED */
+    migration_call_notifiers(s, MIG_EVENT_PRECOPY_FAILED, NULL);
+
+    err = NULL;
+    if (!migration_block_activate(&err)) {
+        /* error was already reported */
+        error_free(err);
+        return;
+    }
+
+    if (runstate_is_live(s->vm_old_state)) {
+        vm_start();
+    }
+}
+
+static int cpr_exec_notifier(NotifierWithReturn *notifier, MigrationEvent *e,
+                             Error **errp)
+{
+    MigrationState *s = migrate_get_current();
+
+    if (e->type == MIG_EVENT_PRECOPY_DONE) {
+        QEMUBH *cpr_exec_bh = qemu_bh_new(cpr_exec_cb, NULL);
+        assert(s->state == MIGRATION_STATUS_COMPLETED);
+        qemu_bh_schedule(cpr_exec_bh);
+        qemu_notify_event();
+    } else if (e->type == MIG_EVENT_PRECOPY_FAILED) {
+        cpr_exec_unpersist_state();
+    }
+    return 0;
+}
+
+void cpr_exec_init(void)
+{
+    static NotifierWithReturn exec_notifier;
+
+    migration_add_notifier_mode(&exec_notifier, cpr_exec_notifier,
+                                MIG_MODE_CPR_EXEC);
+}