diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/Makefile.objs | 1 | ||||
| -rw-r--r-- | util/main-loop.c | 15 | ||||
| -rw-r--r-- | util/qemu-timer.c | 12 | ||||
| -rw-r--r-- | util/rcu.c | 15 | ||||
| -rw-r--r-- | util/sys_membarrier.c | 50 |
5 files changed, 85 insertions, 8 deletions
diff --git a/util/Makefile.objs b/util/Makefile.objs index ae90b9963d..728c3541db 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -33,6 +33,7 @@ util-obj-y += throttle.o util-obj-y += getauxval.o util-obj-y += readline.o util-obj-y += rcu.o +util-obj-$(CONFIG_MEMBARRIER) += sys_membarrier.o util-obj-y += qemu-coroutine.o qemu-coroutine-lock.o qemu-coroutine-io.o util-obj-y += qemu-coroutine-sleep.o util-obj-y += coroutine-$(CONFIG_COROUTINE_BACKEND).o diff --git a/util/main-loop.c b/util/main-loop.c index 7558eb5f53..992f9b0f34 100644 --- a/util/main-loop.c +++ b/util/main-loop.c @@ -29,6 +29,7 @@ #include "qemu/sockets.h" // struct in_addr needed for libslirp.h #include "sysemu/qtest.h" #include "sysemu/cpus.h" +#include "sysemu/replay.h" #include "slirp/libslirp.h" #include "qemu/main-loop.h" #include "block/aio.h" @@ -245,18 +246,19 @@ static int os_host_main_loop_wait(int64_t timeout) timeout = SCALE_MS; } + if (timeout) { spin_counter = 0; - qemu_mutex_unlock_iothread(); } else { spin_counter++; } + qemu_mutex_unlock_iothread(); + replay_mutex_unlock(); ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout); - if (timeout) { - qemu_mutex_lock_iothread(); - } + replay_mutex_lock(); + qemu_mutex_lock_iothread(); glib_pollfds_poll(); @@ -463,8 +465,13 @@ static int os_host_main_loop_wait(int64_t timeout) poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout); qemu_mutex_unlock_iothread(); + + replay_mutex_unlock(); + g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns); + replay_mutex_lock(); + qemu_mutex_lock_iothread(); if (g_poll_ret > 0) { for (i = 0; i < w->num; i++) { diff --git a/util/qemu-timer.c b/util/qemu-timer.c index 82d56507a2..2ed1bf2778 100644 --- a/util/qemu-timer.c +++ b/util/qemu-timer.c @@ -622,6 +622,18 @@ int64_t qemu_clock_get_ns(QEMUClockType type) } } +uint64_t qemu_clock_get_last(QEMUClockType type) +{ + QEMUClock *clock = qemu_clock_ptr(type); + return clock->last; +} + +void qemu_clock_set_last(QEMUClockType type, uint64_t last) +{ + QEMUClock *clock = qemu_clock_ptr(type); + clock->last = last; +} + void qemu_clock_register_reset_notifier(QEMUClockType type, Notifier *notifier) { diff --git a/util/rcu.c b/util/rcu.c index f4d09c8304..5676c22bd1 100644 --- a/util/rcu.c +++ b/util/rcu.c @@ -92,10 +92,11 @@ static void wait_for_readers(void) atomic_set(&index->waiting, true); } - /* Here, order the stores to index->waiting before the - * loads of index->ctr. + /* Here, order the stores to index->waiting before the loads of + * index->ctr. Pairs with smp_mb_placeholder() in rcu_read_unlock(), + * ensuring that the loads of index->ctr are sequentially consistent. */ - smp_mb(); + smp_mb_global(); QLIST_FOREACH_SAFE(index, ®istry, node, tmp) { if (!rcu_gp_ongoing(&index->ctr)) { @@ -142,8 +143,13 @@ static void wait_for_readers(void) void synchronize_rcu(void) { qemu_mutex_lock(&rcu_sync_lock); - qemu_mutex_lock(&rcu_registry_lock); + /* Write RCU-protected pointers before reading p_rcu_reader->ctr. + * Pairs with smp_mb_placeholder() in rcu_read_lock(). + */ + smp_mb_global(); + + qemu_mutex_lock(&rcu_registry_lock); if (!QLIST_EMPTY(®istry)) { /* In either case, the atomic_mb_set below blocks stores that free * old RCU-protected pointers. @@ -370,6 +376,7 @@ static void rcu_init_child(void) static void __attribute__((__constructor__)) rcu_init(void) { + smp_mb_global_init(); #ifdef CONFIG_POSIX pthread_atfork(rcu_init_lock, rcu_init_unlock, rcu_init_child); #endif diff --git a/util/sys_membarrier.c b/util/sys_membarrier.c new file mode 100644 index 0000000000..8dcb53e63e --- /dev/null +++ b/util/sys_membarrier.c @@ -0,0 +1,50 @@ +/* + * Process-global memory barriers + * + * Copyright (c) 2018 Red Hat, Inc. + * + * Author: Paolo Bonzini <pbonzini@redhat.com> + */ + +#include <qemu/osdep.h> +#include <qemu/sys_membarrier.h> +#include <qemu/error-report.h> + +#ifdef CONFIG_LINUX +#include <linux/membarrier.h> +#include <sys/syscall.h> + +static int +membarrier(int cmd, int flags) +{ + return syscall(__NR_membarrier, cmd, flags); +} +#endif + +void smp_mb_global(void) +{ +#if defined CONFIG_WIN32 + FlushProcessWriteBuffers(); +#elif defined CONFIG_LINUX + membarrier(MEMBARRIER_CMD_SHARED, 0); +#else +#error --enable-membarrier is not supported on this operating system. +#endif +} + +void smp_mb_global_init(void) +{ +#ifdef CONFIG_LINUX + int ret = membarrier(MEMBARRIER_CMD_QUERY, 0); + if (ret < 0) { + error_report("This QEMU binary requires the membarrier system call."); + error_report("Please upgrade your system to a newer version of Linux"); + exit(1); + } + if (!(ret & MEMBARRIER_CMD_SHARED)) { + error_report("This QEMU binary requires MEMBARRIER_CMD_SHARED support."); + error_report("Please upgrade your system to a newer version of Linux"); + exit(1); + } +#endif +} |