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qemu-patch-raspberry4
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icount: get rid of static variable 

This patch moves static last_delta variable into timers_state
structure to allow correct vmstate operations with icount shift=auto enabled.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <161701335066.1180180.7104085247702343395.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
stable-6.0
Pavel Dovgalyuk 2021-03-29 13:22:30 +03:00 committed by Paolo Bonzini
parent cb4d9e38bd
commit fe852ac2b3
3 changed files with 8 additions and 8 deletions
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5
softmmu/cpu-timers.c
View File

@ -188,11 +188,12 @@ static const VMStateDescription icount_vmstate_adjust_timers = {
static const VMStateDescription icount_vmstate_shift = {
.name = "timer/icount/shift",
.version_id = 1,
.minimum_version_id = 1,
.version_id = 2,
.minimum_version_id = 2,
.needed = icount_shift_state_needed,
.fields = (VMStateField[]) {
VMSTATE_INT16(icount_time_shift, TimersState),
VMSTATE_INT64(last_delta, TimersState),
VMSTATE_END_OF_LIST()
}
};

9
softmmu/icount.c
View File

@ -176,9 +176,6 @@ static void icount_adjust(void)
int64_t cur_icount;
int64_t delta;
/* Protected by TimersState mutex. */
static int64_t last_delta;
/* If the VM is not running, then do nothing. */
if (!runstate_is_running()) {
return;
@ -193,20 +190,20 @@ static void icount_adjust(void)
delta = cur_icount - cur_time;
/* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */
if (delta > 0
&& last_delta + ICOUNT_WOBBLE < delta * 2
&& timers_state.last_delta + ICOUNT_WOBBLE < delta * 2
&& timers_state.icount_time_shift > 0) {
/* The guest is getting too far ahead. Slow time down. */
qatomic_set(&timers_state.icount_time_shift,
timers_state.icount_time_shift - 1);
}
if (delta < 0
&& last_delta - ICOUNT_WOBBLE > delta * 2
&& timers_state.last_delta - ICOUNT_WOBBLE > delta * 2
&& timers_state.icount_time_shift < MAX_ICOUNT_SHIFT) {
/* The guest is getting too far behind. Speed time up. */
qatomic_set(&timers_state.icount_time_shift,
timers_state.icount_time_shift + 1);
}
last_delta = delta;
timers_state.last_delta = delta;
qatomic_set_i64(&timers_state.qemu_icount_bias,
cur_icount - (timers_state.qemu_icount
<< timers_state.icount_time_shift));

2
softmmu/timers-state.h
View File

@ -43,6 +43,8 @@ typedef struct TimersState {
/* Conversion factor from emulated instructions to virtual clock ticks. */
int16_t icount_time_shift;
/* Icount delta used for shift auto adjust. */
int64_t last_delta;
/* Compensate for varying guest execution speed. */
int64_t qemu_icount_bias;