Return to the main loop where we'll be waken again.
This avoid a tricky race with signals introduced in
commit 219c101fa7f ("Add HVF WFI handler").
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
include/system/hvf_int.h | 1 -
accel/hvf/hvf-accel-ops.c | 5 +--
target/arm/hvf/hvf.c | 74 +++------------------------------------
3 files changed, 8 insertions(+), 72 deletions(-)
diff --git a/include/system/hvf_int.h b/include/system/hvf_int.h
index d842d4b2b99..c8e407a1463 100644
--- a/include/system/hvf_int.h
+++ b/include/system/hvf_int.h
@@ -47,7 +47,6 @@ struct AccelCPUState {
#ifdef __aarch64__
hv_vcpu_exit_t *exit;
bool vtimer_masked;
- sigset_t unblock_ipi_mask;
bool guest_debug_enabled;
#endif
};
diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
index bbb0b385fe9..e9dd2d24745 100644
--- a/accel/hvf/hvf-accel-ops.c
+++ b/accel/hvf/hvf-accel-ops.c
@@ -128,14 +128,15 @@ static int hvf_init_vcpu(CPUState *cpu)
cpu->accel = g_new0(AccelCPUState, 1);
/* init cpu signals */
+ sigset_t unblock_ipi_mask;
struct sigaction sigact;
memset(&sigact, 0, sizeof(sigact));
sigact.sa_handler = dummy_signal;
sigaction(SIG_IPI, &sigact, NULL);
- pthread_sigmask(SIG_BLOCK, NULL, &cpu->accel->unblock_ipi_mask);
- sigdelset(&cpu->accel->unblock_ipi_mask, SIG_IPI);
+ pthread_sigmask(SIG_BLOCK, NULL, &unblock_ipi_mask);
+ sigdelset(&unblock_ipi_mask, SIG_IPI);
#ifdef __aarch64__
r = hv_vcpu_create(&cpu->accel->fd,
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 1abb4a7d7a9..5fc9b217a11 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -301,7 +301,7 @@ void hvf_arm_init_debug(void)
#define TMR_CTL_IMASK (1 << 1)
#define TMR_CTL_ISTATUS (1 << 2)
-static void hvf_wfi(CPUState *cpu);
+static int hvf_wfi(CPUState *cpu);
static uint32_t chosen_ipa_bit_size;
@@ -1703,81 +1703,17 @@ static uint64_t hvf_vtimer_val_raw(void)
return mach_absolute_time() - hvf_state->vtimer_offset;
}
-static uint64_t hvf_vtimer_val(void)
+static int hvf_wfi(CPUState *cpu)
{
- if (!runstate_is_running()) {
- /* VM is paused, the vtimer value is in vtimer.vtimer_val */
- return vtimer.vtimer_val;
- }
-
- return hvf_vtimer_val_raw();
-}
-
-static void hvf_wait_for_ipi(CPUState *cpu, struct timespec *ts)
-{
- /*
- * Use pselect to sleep so that other threads can IPI us while we're
- * sleeping.
- */
- qatomic_set_mb(&cpu->thread_kicked, false);
- bql_unlock();
- pselect(0, 0, 0, 0, ts, &cpu->accel->unblock_ipi_mask);
- bql_lock();
-}
-
-static void hvf_wfi(CPUState *cpu)
-{
- ARMCPU *arm_cpu = ARM_CPU(cpu);
- struct timespec ts;
- hv_return_t r;
- uint64_t ctl;
- uint64_t cval;
- int64_t ticks_to_sleep;
- uint64_t seconds;
- uint64_t nanos;
- uint32_t cntfrq;
-
if (cpu_has_work(cpu)) {
/*
* Don't bother to go into our "low power state" if
* we would just wake up immediately.
*/
- return;
+ return 0;
}
- r = hv_vcpu_get_sys_reg(cpu->accel->fd, HV_SYS_REG_CNTV_CTL_EL0, &ctl);
- assert_hvf_ok(r);
-
- if (!(ctl & 1) || (ctl & 2)) {
- /* Timer disabled or masked, just wait for an IPI. */
- hvf_wait_for_ipi(cpu, NULL);
- return;
- }
-
- r = hv_vcpu_get_sys_reg(cpu->accel->fd, HV_SYS_REG_CNTV_CVAL_EL0, &cval);
- assert_hvf_ok(r);
-
- ticks_to_sleep = cval - hvf_vtimer_val();
- if (ticks_to_sleep < 0) {
- return;
- }
-
- cntfrq = gt_cntfrq_period_ns(arm_cpu);
- seconds = muldiv64(ticks_to_sleep, cntfrq, NANOSECONDS_PER_SECOND);
- ticks_to_sleep -= muldiv64(seconds, NANOSECONDS_PER_SECOND, cntfrq);
- nanos = ticks_to_sleep * cntfrq;
-
- /*
- * Don't sleep for less than the time a context switch would take,
- * so that we can satisfy fast timer requests on the same CPU.
- * Measurements on M1 show the sweet spot to be ~2ms.
- */
- if (!seconds && nanos < (2 * SCALE_MS)) {
- return;
- }
-
- ts = (struct timespec) { seconds, nanos };
- hvf_wait_for_ipi(cpu, &ts);
+ return EXCP_HLT;
}
/* Must be called by the owning thread */
@@ -1967,7 +1903,7 @@ static int hvf_handle_exception(CPUState *cpu, hv_vcpu_exit_exception_t *excp)
case EC_WFX_TRAP:
advance_pc = true;
if (!(syndrome & WFX_IS_WFE)) {
- hvf_wfi(cpu);
+ ret = hvf_wfi(cpu);
}
break;
case EC_AA64_HVC:
--
2.51.0