diff options
Diffstat (limited to 'system/qemu-kvm/patches/deprecate-time-drift-fix.patch')
| -rw-r--r-- | system/qemu-kvm/patches/deprecate-time-drift-fix.patch | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/system/qemu-kvm/patches/deprecate-time-drift-fix.patch b/system/qemu-kvm/patches/deprecate-time-drift-fix.patch new file mode 100644 index 0000000000..56def2d391 --- /dev/null +++ b/system/qemu-kvm/patches/deprecate-time-drift-fix.patch @@ -0,0 +1,150 @@ +From d527b774878defc27f317cdde19b5c54fd0d5666 Mon Sep 17 00:00:00 2001 +From: Jan Kiszka <jan.kiszka@siemens.com> +Date: Sun, 15 Jan 2012 12:06:12 +0100 +Subject: [PATCH] qemu-kvm: Deprecate time drift fix + +Remove this divergence from upstream. It is practically unused today as +the default mode is in-kernel irqchip. We keep the command line switch +for now, adding a warning that there is no effect anymore. + +The feature can be reintroduced to upstream once we have IRQ paths with +feedback support. + +Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> +Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> +--- + hw/i8254.c | 28 ++-------------------------- + hw/i8259.c | 17 ----------------- + qemu-options.hx | 4 ++-- + vl.c | 4 ++-- + 4 files changed, 6 insertions(+), 47 deletions(-) + +diff --git a/hw/i8254.c b/hw/i8254.c +index d73a5f2..50ecceb 100644 +--- a/hw/i8254.c ++++ b/hw/i8254.c +@@ -347,11 +347,6 @@ static uint32_t pit_ioport_read(void *opaque, uint32_t addr) + return ret; + } + +-/* global counters for time-drift fix */ +-int64_t timer_acks=0, timer_interrupts=0, timer_ints_to_push=0; +- +-extern int time_drift_fix; +- + static void pit_irq_timer_update(PITChannelState *s, int64_t current_time) + { + int64_t expire_time; +@@ -362,35 +357,16 @@ static void pit_irq_timer_update(PITChannelState *s, int64_t current_time) + expire_time = pit_get_next_transition_time(s, current_time); + irq_level = pit_get_out1(s, current_time); + qemu_set_irq(s->irq, irq_level); +- if (time_drift_fix && irq_level==1) { +- /* FIXME: fine tune timer_max_fix (max fix per tick). +- * Should it be 1 (double time), 2 , 4, 10 ? +- * Currently setting it to 5% of PIT-ticks-per-second (per PIT-tick) +- */ +- const long pit_ticks_per_sec = (s->count>0) ? (PIT_FREQ/s->count) : 0; +- const long timer_max_fix = pit_ticks_per_sec/20; +- const long delta = timer_interrupts - timer_acks; +- const long max_delta = pit_ticks_per_sec * 60; /* one minute */ +- if ((delta > max_delta) && (pit_ticks_per_sec > 0)) { +- printf("time drift is too long, %ld seconds were lost\n", delta/pit_ticks_per_sec); +- timer_acks = timer_interrupts; +- timer_ints_to_push = 0; +- } else if (delta > 0) { +- timer_ints_to_push = MIN(delta, timer_max_fix); +- } +- timer_interrupts++; +- } + #ifdef DEBUG_PIT + printf("irq_level=%d next_delay=%f\n", + irq_level, + (double)(expire_time - current_time) / get_ticks_per_sec()); + #endif + s->next_transition_time = expire_time; +- if (expire_time != -1) { ++ if (expire_time != -1) + qemu_mod_timer(s->irq_timer, expire_time); +- } else { ++ else + qemu_del_timer(s->irq_timer); +- } + } + + static void pit_irq_timer(void *opaque) +diff --git a/hw/i8259.c b/hw/i8259.c +index 7e17071..0632ea2 100644 +--- a/hw/i8259.c ++++ b/hw/i8259.c +@@ -210,9 +210,6 @@ static void pic_intack(PicState *s, int irq) + pic_update_irq(s); + } + +-extern int time_drift_fix; +-extern int64_t timer_acks, timer_ints_to_push; +- + int pic_read_irq(PicState *s) + { + int irq, irq2, intno; +@@ -232,20 +229,6 @@ int pic_read_irq(PicState *s) + intno = s->irq_base + irq; + } + pic_intack(s, irq); +- +- /* FIXME: limit to x86, or better, to platforms where irq0 is the +- * timer interrupts. */ +- +- if (time_drift_fix && s->master && irq == 0) { +- timer_acks++; +- if (timer_ints_to_push > 0) { +- timer_ints_to_push--; +- /* simulate an edge irq0, like the one generated by i8254 */ +- pic_set_irq(s, 0, 0); +- pic_set_irq(s, 0, 1); +- } +- } +- + } else { + /* spurious IRQ on host controller */ + irq = 7; +diff --git a/qemu-options.hx b/qemu-options.hx +index c645f87..d567ba3 100644 +--- a/qemu-options.hx ++++ b/qemu-options.hx +@@ -2633,8 +2633,8 @@ DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, + "-no-kvm-pit-reinjection\n" + " disable KVM kernel mode PIT interrupt reinjection\n", + QEMU_ARCH_I386) +-DEF("tdf", 0, QEMU_OPTION_tdf, +- "-tdf enable guest time drift compensation\n", QEMU_ARCH_ALL) ++HXCOMM -tdf is deprecated and ignored today ++DEF("tdf", 0, QEMU_OPTION_tdf, "", QEMU_ARCH_ALL) + DEF("kvm-shadow-memory", HAS_ARG, QEMU_OPTION_kvm_shadow_memory, + "-kvm-shadow-memory MEGABYTES\n" + " allocate MEGABYTES for kvm mmu shadowing\n", +diff --git a/vl.c b/vl.c +index c009eb8..1a77de1 100644 +--- a/vl.c ++++ b/vl.c +@@ -222,7 +222,6 @@ const char *watchdog; + QEMUOptionRom option_rom[MAX_OPTION_ROMS]; + int nb_option_roms; + int semihosting_enabled = 0; +-int time_drift_fix = 0; + unsigned int kvm_shadow_memory = 0; + int old_param = 0; + const char *qemu_name; +@@ -2955,7 +2954,8 @@ int main(int argc, char **argv, char **envp) + semihosting_enabled = 1; + break; + case QEMU_OPTION_tdf: +- time_drift_fix = 1; ++ fprintf(stderr, "Warning: user space PIT time drift fix " ++ "is no longer supported.\n"); + break; + case QEMU_OPTION_kvm_shadow_memory: + kvm_shadow_memory = (int64_t)atoi(optarg) * 1024 * 1024 / 4096; +-- +1.7.6.5 + |