summaryrefslogtreecommitdiffstats
path: root/qemu-doc.texi
diff options
context:
space:
mode:
Diffstat (limited to 'qemu-doc.texi')
-rw-r--r--qemu-doc.texi11
1 files changed, 11 insertions, 0 deletions
diff --git a/qemu-doc.texi b/qemu-doc.texi
index e864117..057b9f6 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -965,6 +965,17 @@ On M68K this implements the "ColdFire GDB" interface used by libgloss.
Note that this allows guest direct access to the host filesystem,
so should only be used with trusted guest OS.
+
+@item -icount [N|auto]
+Enable virtual instruction counter. The virtual cpu will execute one
+instruction every 2^N ns of virtual time. If @code{auto} is specified
+then the virtual cpu speed will be automatically adjusted to keep virtual
+time within a few seconds of real time.
+
+Note that while this option can give deterministic behavior, it does not
+provide cycle accurate emulation. Modern CPUs contain superscalar out of
+order cores with complex cache heirachies. The number of instructions
+executed often has little or no correlation with actual performance.
@end table
@c man end
OpenPOWER on IntegriCloud