diff options
| -rw-r--r-- | cpus.c | 9 | ||||
| -rw-r--r-- | qemu-options.hx | 12 | ||||
| -rw-r--r-- | vl.c | 3 |
3 files changed, 22 insertions, 2 deletions
@@ -520,11 +520,18 @@ void configure_icount(QemuOpts *opts, Error **errp) } return; } + + icount_sleep = qemu_opt_get_bool(opts, "sleep", true); if (icount_sleep) { icount_warp_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT, icount_warp_rt, NULL); } + icount_align_option = qemu_opt_get_bool(opts, "align", false); + + if (icount_align_option && !icount_sleep) { + error_setg(errp, "align=on and sleep=no are incompatible"); + } if (strcmp(option, "auto") != 0) { errno = 0; icount_time_shift = strtol(option, &rem_str, 0); @@ -535,6 +542,8 @@ void configure_icount(QemuOpts *opts, Error **errp) return; } else if (icount_align_option) { error_setg(errp, "shift=auto and align=on are incompatible"); + } else if (!icount_sleep) { + error_setg(errp, "shift=auto and sleep=no are incompatible"); } use_icount = 2; diff --git a/qemu-options.hx b/qemu-options.hx index b3db6cbe86..85883f165a 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3100,9 +3100,10 @@ re-inject them. ETEXI DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ - "-icount [shift=N|auto][,align=on|off]\n" \ + "-icount [shift=N|auto][,align=on|off][,sleep=no]\n" \ " enable virtual instruction counter with 2^N clock ticks per\n" \ - " instruction and enable aligning the host and virtual clocks\n", QEMU_ARCH_ALL) + " instruction, enable aligning the host and virtual clocks\n" \ + " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) STEXI @item -icount [shift=@var{N}|auto] @findex -icount @@ -3111,6 +3112,13 @@ instruction every 2^@var{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. +When the virtual cpu is sleeping, the virtual time will advance at default +speed unless @option{sleep=no} is specified. +With @option{sleep=no}, the virtual time will jump to the next timer deadline +instantly whenever the virtual cpu goes to sleep mode and will not advance +if no timer is enabled. This behavior give deterministic execution times from +the guest point of view. + 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 hierarchies. The number of instructions @@ -468,6 +468,9 @@ static QemuOptsList qemu_icount_opts = { }, { .name = "align", .type = QEMU_OPT_BOOL, + }, { + .name = "sleep", + .type = QEMU_OPT_BOOL, }, { /* end of list */ } }, |