51 lines
1.2 KiB
C
51 lines
1.2 KiB
C
/*
|
|
* 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
|
|
}
|