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authorPeter Maydell2018-03-16 12:05:03 +0100
committerPeter Maydell2018-03-16 12:05:03 +0100
commit3788c7b6e56fa34ee2a73e41706eb2a2447ba75a (patch)
tree8f016e7c9175686b4d7c2d1847c8cc877102dc6b /util/sys_membarrier.c
parentMerge remote-tracking branch 'remotes/awilliam/tags/vfio-update-20180313.0' i... (diff)
parenttcg: fix cpu_io_recompile (diff)
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging
* Record-replay lockstep execution, log dumper and fixes (Alex, Pavel) * SCSI fix to pass maximum transfer size (Daniel Barboza) * chardev fixes and improved iothread support (Daniel Berrangé, Peter) * checkpatch tweak (Eric) * make help tweak (Marc-André) * make more PCI NICs available with -net or -nic (myself) * change default q35 NIC to e1000e (myself) * SCSI support for NDOB bit (myself) * membarrier system call support (myself) * SuperIO refactoring (Philippe) * miscellaneous cleanups and fixes (Thomas) # gpg: Signature made Mon 12 Mar 2018 16:10:52 GMT # gpg: using RSA key BFFBD25F78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * remotes/bonzini/tags/for-upstream: (69 commits) tcg: fix cpu_io_recompile replay: update documentation replay: save vmstate of the asynchronous events replay: don't process async events when warping the clock scripts/replay-dump.py: replay log dumper replay: avoid recursive call of checkpoints replay: check return values of fwrite replay: push replay_mutex_lock up the call tree replay: don't destroy mutex at exit replay: make locking visible outside replay code replay/replay-internal.c: track holding of replay_lock replay/replay.c: bump REPLAY_VERSION again replay: save prior value of the host clock replay: added replay log format description replay: fix save/load vm for non-empty queue replay: fixed replay_enable_events replay: fix processing async events cpu-exec: fix exception_index handling hw/i386/pc: Factor out the superio code hw/alpha/dp264: Use the TYPE_SMC37C669_SUPERIO ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org> # Conflicts: # default-configs/i386-softmmu.mak # default-configs/x86_64-softmmu.mak
Diffstat (limited to 'util/sys_membarrier.c')
-rw-r--r--util/sys_membarrier.c50
1 files changed, 50 insertions, 0 deletions
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
+}