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From: Steve Sistare <steven.sistare@oracle.com>
To: qemu-devel@nongnu.org
Cc: Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>,
	David Hildenbrand <david@redhat.com>,
	Igor Mammedov <imammedo@redhat.com>,
	Eduardo Habkost <eduardo@habkost.net>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	Philippe Mathieu-Daude <philmd@linaro.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"Daniel P. Berrange" <berrange@redhat.com>,
	Markus Armbruster <armbru@redhat.com>,
	Steve Sistare <steven.sistare@oracle.com>
Subject: [PATCH V1 06/26] migration: precreate vmstate for exec
Date: Mon, 29 Apr 2024 08:55:15 -0700	[thread overview]
Message-ID: <1714406135-451286-7-git-send-email-steven.sistare@oracle.com> (raw)
In-Reply-To: <1714406135-451286-1-git-send-email-steven.sistare@oracle.com>

Provide migration_precreate_save for saving precreate vmstate across exec.
Create a memfd, save its value in the environment, and serialize state
to it.  Reverse the process in migration_precreate_load.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 include/migration/misc.h |   5 ++
 migration/meson.build    |   1 +
 migration/precreate.c    | 139 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 145 insertions(+)
 create mode 100644 migration/precreate.c

diff --git a/include/migration/misc.h b/include/migration/misc.h
index c9e200f..cf30351 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -56,6 +56,11 @@ AnnounceParameters *migrate_announce_params(void);
 
 void dump_vmstate_json_to_file(FILE *out_fp);
 
+/* migration/precreate.c */
+int migration_precreate_save(Error **errp);
+void migration_precreate_unsave(void);
+int migration_precreate_load(Error **errp);
+
 /* migration/migration.c */
 void migration_object_init(void);
 void migration_shutdown(void);
diff --git a/migration/meson.build b/migration/meson.build
index f76b1ba..50e7cb2 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -26,6 +26,7 @@ system_ss.add(files(
   'ram-compress.c',
   'options.c',
   'postcopy-ram.c',
+  'precreate.c',
   'savevm.c',
   'socket.c',
   'tls.c',
diff --git a/migration/precreate.c b/migration/precreate.c
new file mode 100644
index 0000000..0bf5e1f
--- /dev/null
+++ b/migration/precreate.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qemu/memfd.h"
+#include "qapi/error.h"
+#include "io/channel-file.h"
+#include "migration/misc.h"
+#include "migration/qemu-file.h"
+#include "migration/savevm.h"
+
+#define PRECREATE_STATE_NAME "QEMU_PRECREATE_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);
+}
+
+static int memfd_create_named(const char *name, Error **errp)
+{
+    int mfd;
+    char val[16];
+
+    mfd = memfd_create(name, 0);
+    if (mfd < 0) {
+        error_setg_errno(errp, errno, "memfd_create failed");
+        return -1;
+    }
+
+    /* Remember mfd in environment for post-exec load */
+    qemu_clear_cloexec(mfd);
+    snprintf(val, sizeof(val), "%d", mfd);
+    g_setenv(name, val, 1);
+
+    return mfd;
+}
+
+static int memfd_find_named(const char *name, int *mfd_p, Error **errp)
+{
+    const char *val = g_getenv(name);
+
+    if (!val) {
+        *mfd_p = -1;
+        return 0;       /* No memfd was created, not an error */
+    }
+    g_unsetenv(name);
+    if (qemu_strtoi(val, NULL, 10, mfd_p)) {
+        error_setg(errp, "Bad %s env value %s", PRECREATE_STATE_NAME, val);
+        return -1;
+    }
+    lseek(*mfd_p, 0, SEEK_SET);
+    return 0;
+}
+
+static void memfd_delete_named(const char *name)
+{
+    int mfd;
+    const char *val = g_getenv(name);
+
+    if (val) {
+        g_unsetenv(name);
+        if (!qemu_strtoi(val, NULL, 10, &mfd)) {
+            close(mfd);
+        }
+    }
+}
+
+static QEMUFile *qemu_file_new_memfd_output(const char *name, Error **errp)
+{
+    int mfd = memfd_create_named(name, errp);
+
+    if (mfd < 0) {
+        return NULL;
+    }
+
+    return qemu_file_new_fd_output(mfd, name);
+}
+
+static QEMUFile *qemu_file_new_memfd_input(const char *name, Error **errp)
+{
+    int ret, mfd;
+
+    ret = memfd_find_named(name, &mfd, errp);
+    if (ret || mfd < 0) {
+        return NULL;
+    }
+
+    return qemu_file_new_fd_input(mfd, name);
+}
+
+int migration_precreate_save(Error **errp)
+{
+    QEMUFile *f = qemu_file_new_memfd_output(PRECREATE_STATE_NAME, errp);
+
+    if (!f) {
+        return -1;
+    } else if (qemu_savevm_precreate_save(f, errp)) {
+        memfd_delete_named(PRECREATE_STATE_NAME);
+        return -1;
+    } else {
+        /* Do not close f, as mfd must remain open. */
+        return 0;
+    }
+}
+
+void migration_precreate_unsave(void)
+{
+    memfd_delete_named(PRECREATE_STATE_NAME);
+}
+
+int migration_precreate_load(Error **errp)
+{
+    int ret;
+    QEMUFile *f = qemu_file_new_memfd_input(PRECREATE_STATE_NAME, errp);
+
+    if (!f) {
+        return -1;
+    }
+    ret = qemu_savevm_precreate_load(f, errp);
+    qemu_fclose(f);
+    g_unsetenv(PRECREATE_STATE_NAME);
+    return ret;
+}
-- 
1.8.3.1



  parent reply	other threads:[~2024-04-29 15:57 UTC|newest]

Thread overview: 113+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-29 15:55 [PATCH V1 00/26] Live update: cpr-exec Steve Sistare
2024-04-29 15:55 ` [PATCH V1 01/26] oslib: qemu_clear_cloexec Steve Sistare
2024-05-06 23:27   ` Fabiano Rosas
2024-05-07  8:56     ` Daniel P. Berrangé
2024-05-07 13:54       ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 02/26] vl: helper to request re-exec Steve Sistare
2024-04-29 15:55 ` [PATCH V1 03/26] migration: SAVEVM_FOREACH Steve Sistare
2024-05-06 23:17   ` Fabiano Rosas
2024-05-13 19:27     ` Steven Sistare
2024-05-27 18:14       ` Peter Xu
2024-04-29 15:55 ` [PATCH V1 04/26] migration: delete unused parameter mis Steve Sistare
2024-05-06 21:50   ` Fabiano Rosas
2024-05-27 18:02   ` Peter Xu
2024-04-29 15:55 ` [PATCH V1 05/26] migration: precreate vmstate Steve Sistare
2024-05-07 21:02   ` Fabiano Rosas
2024-05-13 19:28     ` Steven Sistare
2024-05-24 13:56   ` Fabiano Rosas
2024-05-27 18:16   ` Peter Xu
2024-05-28 15:09     ` Steven Sistare via
2024-05-29 18:39       ` Peter Xu
2024-05-30 17:04         ` Steven Sistare via
2024-04-29 15:55 ` Steve Sistare [this message]
2024-05-06 23:34   ` [PATCH V1 06/26] migration: precreate vmstate for exec Fabiano Rosas
2024-05-13 19:28     ` Steven Sistare
2024-05-13 21:21       ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 07/26] migration: VMStateId Steve Sistare
2024-05-07 21:03   ` Fabiano Rosas
2024-05-27 18:20   ` Peter Xu
2024-05-28 15:10     ` Steven Sistare via
2024-05-28 17:44       ` Peter Xu
2024-05-29 17:30         ` Steven Sistare via
2024-05-29 18:53           ` Peter Xu
2024-05-30 17:11             ` Steven Sistare via
2024-05-30 18:03               ` Peter Xu
2024-04-29 15:55 ` [PATCH V1 08/26] migration: vmstate_info_void_ptr Steve Sistare
2024-05-07 21:33   ` Fabiano Rosas
2024-05-27 18:31   ` Peter Xu
2024-05-28 15:10     ` Steven Sistare via
2024-05-28 18:21       ` Peter Xu
2024-05-29 17:30         ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 09/26] migration: vmstate_register_named Steve Sistare
2024-05-09 14:19   ` Fabiano Rosas
2024-05-09 14:32     ` Fabiano Rosas
2024-05-13 19:29       ` Steven Sistare
2024-04-29 15:55 ` [PATCH V1 10/26] migration: vmstate_unregister_named Steve Sistare
2024-04-29 15:55 ` [PATCH V1 11/26] migration: vmstate_register at init time Steve Sistare
2024-04-29 15:55 ` [PATCH V1 12/26] migration: vmstate factory object Steve Sistare
2024-04-29 15:55 ` [PATCH V1 13/26] physmem: ram_block_create Steve Sistare
2024-05-13 18:37   ` Fabiano Rosas
2024-05-13 19:30     ` Steven Sistare
2024-04-29 15:55 ` [PATCH V1 14/26] physmem: hoist guest_memfd creation Steve Sistare
2024-04-29 15:55 ` [PATCH V1 15/26] physmem: hoist host memory allocation Steve Sistare
2024-04-29 15:55 ` [PATCH V1 16/26] physmem: set ram block idstr earlier Steve Sistare
2024-04-29 15:55 ` [PATCH V1 17/26] machine: memfd-alloc option Steve Sistare
2024-05-28 21:12   ` Peter Xu
2024-05-29 17:31     ` Steven Sistare via
2024-05-29 19:14       ` Peter Xu
2024-05-30 17:11         ` Steven Sistare via
2024-05-30 18:14           ` Peter Xu
2024-05-31 19:32             ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 18/26] migration: cpr-exec-args parameter Steve Sistare
2024-05-02 12:23   ` Markus Armbruster
2024-05-02 16:00     ` Steven Sistare
2024-05-21  8:13   ` Daniel P. Berrangé
2024-04-29 15:55 ` [PATCH V1 19/26] physmem: preserve ram blocks for cpr Steve Sistare
2024-05-28 21:44   ` Peter Xu
2024-05-29 17:31     ` Steven Sistare via
2024-05-29 19:25       ` Peter Xu
2024-05-30 17:12         ` Steven Sistare via
2024-05-30 18:39           ` Peter Xu
2024-05-31 19:32             ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 20/26] migration: cpr-exec mode Steve Sistare
2024-05-02 12:23   ` Markus Armbruster
2024-05-02 16:00     ` Steven Sistare
2024-05-03  6:26       ` Markus Armbruster
2024-05-21  8:20   ` Daniel P. Berrangé
2024-05-24 14:58   ` Fabiano Rosas
2024-05-27 18:54     ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 21/26] migration: migrate_add_blocker_mode Steve Sistare
2024-05-09 17:47   ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 22/26] migration: ram block cpr-exec blockers Steve Sistare
2024-05-09 18:01   ` Fabiano Rosas
2024-05-13 19:29     ` Steven Sistare
2024-04-29 15:55 ` [PATCH V1 23/26] migration: misc " Steve Sistare
2024-05-09 18:05   ` Fabiano Rosas
2024-05-24 12:40   ` Fabiano Rosas
2024-05-27 19:02     ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 24/26] seccomp: cpr-exec blocker Steve Sistare
2024-05-09 18:16   ` Fabiano Rosas
2024-05-10  7:54   ` Daniel P. Berrangé
2024-05-13 19:29     ` Steven Sistare
2024-05-21  7:14       ` Daniel P. Berrangé
2024-04-29 15:55 ` [PATCH V1 25/26] migration: fix mismatched GPAs during cpr-exec Steve Sistare
2024-05-09 18:39   ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 26/26] migration: only-migratable-modes Steve Sistare
2024-05-09 19:14   ` Fabiano Rosas
2024-05-13 19:48     ` Steven Sistare
2024-05-13 21:57       ` Fabiano Rosas
2024-05-21  8:05   ` Daniel P. Berrangé
2024-05-02 16:13 ` cpr-exec doc (was Re: [PATCH V1 00/26] Live update: cpr-exec) Steven Sistare
2024-05-02 18:15   ` Peter Xu
2024-05-20 18:30 ` [PATCH V1 00/26] Live update: cpr-exec Steven Sistare
2024-05-20 22:28   ` Fabiano Rosas
2024-05-21  2:31     ` Peter Xu
2024-05-21 11:46       ` Steven Sistare
2024-05-27 17:45         ` Peter Xu
2024-05-28 15:10           ` Steven Sistare via
2024-05-28 16:42             ` Peter Xu
2024-05-30 17:17               ` Steven Sistare via
2024-05-30 19:23                 ` Peter Xu
2024-05-24 13:02 ` Fabiano Rosas
2024-05-24 14:07   ` Steven Sistare
2024-05-27 18:07 ` Peter Xu

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