7 files changed, 145 insertions, 29 deletions
diff --git a/include/qemu/accel.h b/include/qemu/accel.h
index b9d6d69eb8..4f4c283f6f 100644
--- a/include/qemu/accel.h
+++ b/include/qemu/accel.h
@@ -78,4 +78,17 @@ int accel_init_machine(AccelState *accel, MachineState *ms);
 void accel_setup_post(MachineState *ms);
 #endif /* !CONFIG_USER_ONLY */
 
+/**
+ * accel_cpu_instance_init:
+ * @cpu: The CPU that needs to do accel-specific object initializations.
+ */
+void accel_cpu_instance_init(CPUState *cpu);
+
+/**
+ * accel_cpu_realizefn:
+ * @cpu: The CPU that needs to call accel-specific cpu realization.
+ * @errp: currently unused.
+ */
+bool accel_cpu_realizefn(CPUState *cpu, Error **errp);
+
 #endif /* QEMU_ACCEL_H */
diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
index 4aaf992b5d..2d3bb8bbed 100644
--- a/include/qemu/bswap.h
+++ b/include/qemu/bswap.h
@@ -1,8 +1,6 @@
 #ifndef BSWAP_H
 #define BSWAP_H
 
-#include "fpu/softfloat-types.h"
-
 #ifdef CONFIG_MACHINE_BSWAP_H
 # include <sys/endian.h>
 # include <machine/bswap.h>
@@ -12,7 +10,18 @@
 # include <endian.h>
 #elif defined(CONFIG_BYTESWAP_H)
 # include <byteswap.h>
+#define BSWAP_FROM_BYTESWAP
+# else
+#define BSWAP_FROM_FALLBACKS
+#endif /* ! CONFIG_MACHINE_BSWAP_H */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "fpu/softfloat-types.h"
+
+#ifdef BSWAP_FROM_BYTESWAP
 static inline uint16_t bswap16(uint16_t x)
 {
     return bswap_16(x);
@@ -27,7 +36,9 @@ static inline uint64_t bswap64(uint64_t x)
 {
     return bswap_64(x);
 }
-# else
+#endif
+
+#ifdef BSWAP_FROM_FALLBACKS
 static inline uint16_t bswap16(uint16_t x)
 {
     return (((x & 0x00ff) << 8) |
@@ -53,7 +64,10 @@ static inline uint64_t bswap64(uint64_t x)
             ((x & 0x00ff000000000000ULL) >> 40) |
             ((x & 0xff00000000000000ULL) >> 56));
 }
-#endif /* ! CONFIG_MACHINE_BSWAP_H */
+#endif
+
+#undef BSWAP_FROM_BYTESWAP
+#undef BSWAP_FROM_FALLBACKS
 
 static inline void bswap16s(uint16_t *s)
 {
@@ -494,4 +508,8 @@ DO_STN_LDN_P(be)
 #undef le_bswaps
 #undef be_bswaps
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* BSWAP_H */
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index cf28bb2bcd..091c45248b 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -11,6 +11,12 @@
 #define QEMU_STATIC_ANALYSIS 1
 #endif
 
+#ifdef __cplusplus
+#define QEMU_EXTERN_C extern "C"
+#else
+#define QEMU_EXTERN_C extern
+#endif
+
 #define QEMU_NORETURN __attribute__ ((__noreturn__))
 
 #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index d6892fd208..98aef5647c 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -234,24 +234,6 @@ void event_notifier_set_handler(EventNotifier *e,
 
 GSource *iohandler_get_g_source(void);
 AioContext *iohandler_get_aio_context(void);
-#ifdef CONFIG_POSIX
-/**
- * qemu_add_child_watch: Register a child process for reaping.
- *
- * Under POSIX systems, a parent process must read the exit status of
- * its child processes using waitpid, or the operating system will not
- * free some of the resources attached to that process.
- *
- * This function directs the QEMU main loop to observe a child process
- * and call waitpid as soon as it exits; the watch is then removed
- * automatically.  It is useful whenever QEMU forks a child process
- * but will find out about its termination by other means such as a
- * "broken pipe".
- *
- * @pid: The pid that QEMU should observe.
- */
-int qemu_add_child_watch(pid_t pid);
-#endif
 
 /**
  * qemu_mutex_iothread_locked: Return lock status of the main loop mutex.
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index ba15be9c56..4c6f2390be 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -57,7 +57,7 @@
 #define daemon qemu_fake_daemon_function
 #include <stdlib.h>
 #undef daemon
-extern int daemon(int, int);
+QEMU_EXTERN_C int daemon(int, int);
 #endif
 
 #ifdef _WIN32
@@ -104,6 +104,15 @@ extern int daemon(int, int);
 #include <setjmp.h>
 #include <signal.h>
 
+#ifdef CONFIG_IOVEC
+#include <sys/uio.h>
+#endif
+
+#if defined(__linux__) && defined(__sparc__)
+/* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */
+#include <sys/shm.h>
+#endif
+
 #ifndef _WIN32
 #include <sys/wait.h>
 #else
@@ -111,6 +120,17 @@ extern int daemon(int, int);
 #define WEXITSTATUS(x) (x)
 #endif
 
+#ifdef __APPLE__
+#include <AvailabilityMacros.h>
+#endif
+
+/*
+ * This is somewhat like a system header; it must be outside any extern "C"
+ * block because it includes system headers itself, including glib.h,
+ * which will not compile if inside an extern "C" block.
+ */
+#include "glib-compat.h"
+
 #ifdef _WIN32
 #include "sysemu/os-win32.h"
 #endif
@@ -119,11 +139,10 @@ extern int daemon(int, int);
 #include "sysemu/os-posix.h"
 #endif
 
-#ifdef __APPLE__
-#include <AvailabilityMacros.h>
+#ifdef __cplusplus
+extern "C" {
 #endif
 
-#include "glib-compat.h"
 #include "qemu/typedefs.h"
 
 /*
@@ -459,7 +478,6 @@ void qemu_anon_ram_free(void *ptr, size_t size);
    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
 #elif defined(__linux__) && defined(__sparc__)
-#include <sys/shm.h>
 #  define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size, SHMLBA)
 #else
 #  define QEMU_VMALLOC_ALIGN qemu_real_host_page_size
@@ -539,8 +557,6 @@ struct iovec {
 
 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
-#else
-#include <sys/uio.h>
 #endif
 
 #ifdef _WIN32
@@ -722,4 +738,8 @@ static inline int platform_does_not_support_system(const char *command)
 }
 #endif /* !HAVE_SYSTEM_FUNCTION */
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/include/qemu/ratelimit.h b/include/qemu/ratelimit.h
index 01da8d63f1..003ea6d5a3 100644
--- a/include/qemu/ratelimit.h
+++ b/include/qemu/ratelimit.h
@@ -14,9 +14,11 @@
 #ifndef QEMU_RATELIMIT_H
 #define QEMU_RATELIMIT_H
 
+#include "qemu/lockable.h"
 #include "qemu/timer.h"
 
 typedef struct {
+    QemuMutex lock;
     int64_t slice_start_time;
     int64_t slice_end_time;
     uint64_t slice_quota;
@@ -40,6 +42,7 @@ static inline int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)
     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
     double delay_slices;
 
+    QEMU_LOCK_GUARD(&limit->lock);
     assert(limit->slice_quota && limit->slice_ns);
 
     if (limit->slice_end_time < now) {
@@ -65,9 +68,20 @@ static inline int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)
     return limit->slice_end_time - now;
 }
 
+static inline void ratelimit_init(RateLimit *limit)
+{
+    qemu_mutex_init(&limit->lock);
+}
+
+static inline void ratelimit_destroy(RateLimit *limit)
+{
+    qemu_mutex_destroy(&limit->lock);
+}
+
 static inline void ratelimit_set_speed(RateLimit *limit, uint64_t speed,
                                        uint64_t slice_ns)
 {
+    QEMU_LOCK_GUARD(&limit->lock);
     limit->slice_ns = slice_ns;
     limit->slice_quota = MAX(((double)speed * slice_ns) / 1000000000ULL, 1);
 }
diff --git a/include/qemu/transactions.h b/include/qemu/transactions.h
new file mode 100644
index 0000000000..92c5965235
--- /dev/null
+++ b/include/qemu/transactions.h
@@ -0,0 +1,63 @@
+/*
+ * Simple transactions API
+ *
+ * Copyright (c) 2021 Virtuozzo International GmbH.
+ *
+ * Author:
+ *  Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * = Generic transaction API =
+ *
+ * The intended usage is the following: you create "prepare" functions, which
+ * represents the actions. They will usually have Transaction* argument, and
+ * call tran_add() to register finalization callbacks. For finalization
+ * callbacks, prepare corresponding TransactionActionDrv structures.
+ *
+ * Then, when you need to make a transaction, create an empty Transaction by
+ * tran_create(), call your "prepare" functions on it, and finally call
+ * tran_abort() or tran_commit() to finalize the transaction by corresponding
+ * finalization actions in reverse order.
+ */
+
+#ifndef QEMU_TRANSACTIONS_H
+#define QEMU_TRANSACTIONS_H
+
+#include <gmodule.h>
+
+typedef struct TransactionActionDrv {
+    void (*abort)(void *opaque);
+    void (*commit)(void *opaque);
+    void (*clean)(void *opaque);
+} TransactionActionDrv;
+
+typedef struct Transaction Transaction;
+
+Transaction *tran_new(void);
+void tran_add(Transaction *tran, TransactionActionDrv *drv, void *opaque);
+void tran_abort(Transaction *tran);
+void tran_commit(Transaction *tran);
+
+static inline void tran_finalize(Transaction *tran, int ret)
+{
+    if (ret < 0) {
+        tran_abort(tran);
+    } else {
+        tran_commit(tran);
+    }
+}
+
+#endif /* QEMU_TRANSACTIONS_H */