Re: [PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
On 02.12.20 02:52, Peter Collingbourne wrote:
On Tue, Dec 1, 2020 at 5:39 PM Alexander Graf wrote:
On 02.12.20 02:32, Peter Collingbourne wrote:
On Tue, Dec 1, 2020 at 3:24 PM Alexander Graf wrote:
On 01.12.20 22:00, Peter Collingbourne wrote:
Sleep on WFx until the VTIMER is due but allow ourselves to be woken
up on IPI.
Signed-off-by: Peter Collingbourne
---
v2:
- simplify locking further
- wait indefinitely on disabled or masked timers
accel/hvf/hvf-cpus.c | 5 +-
include/sysemu/hvf_int.h | 3 +-
target/arm/hvf/hvf.c | 116 ++-
3 files changed, 43 insertions(+), 81 deletions(-)
diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
index 4360f64671..b2c8fb57f6 100644
--- a/accel/hvf/hvf-cpus.c
+++ b/accel/hvf/hvf-cpus.c
@@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
sigact.sa_handler = dummy_signal;
sigaction(SIG_IPI, , NULL);
-pthread_sigmask(SIG_BLOCK, NULL, );
-sigdelset(, SIG_IPI);
-pthread_sigmask(SIG_SETMASK, , NULL);
+pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
+sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
#ifdef __aarch64__
r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t **)>hvf->exit,
NULL);
diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
index c56baa3ae8..13adf6ea77 100644
--- a/include/sysemu/hvf_int.h
+++ b/include/sysemu/hvf_int.h
@@ -62,8 +62,7 @@ extern HVFState *hvf_state;
struct hvf_vcpu_state {
uint64_t fd;
void *exit;
-struct timespec ts;
-bool sleeping;
+sigset_t unblock_ipi_mask;
};
void assert_hvf_ok(hv_return_t ret);
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 8fe10966d2..3321d48aa2 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -2,6 +2,7 @@
* QEMU Hypervisor.framework support for Apple Silicon
* Copyright 2020 Alexander Graf
+ * Copyright 2020 Google LLC
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
@@ -18,6 +19,7 @@
#include "sysemu/hw_accel.h"
#include
+#include
#include "exec/address-spaces.h"
#include "hw/irq.h"
@@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
void hvf_kick_vcpu_thread(CPUState *cpu)
{
-if (cpu->hvf->sleeping) {
-/*
- * When sleeping, make sure we always send signals. Also, clear the
- * timespec, so that an IPI that arrives between setting hvf->sleeping
- * and the nanosleep syscall still aborts the sleep.
- */
-cpu->thread_kicked = false;
-cpu->hvf->ts = (struct timespec){ };
-cpus_kick_thread(cpu);
-} else {
-hv_vcpus_exit(>hvf->fd, 1);
-}
+cpus_kick_thread(cpu);
+hv_vcpus_exit(>hvf->fd, 1);
}
static int hvf_inject_interrupts(CPUState *cpu)
@@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
return 0;
}
+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_mb_set(>thread_kicked, false);
+qemu_mutex_unlock_iothread();
+pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
+qemu_mutex_lock_iothread();
+}
+
int hvf_vcpu_exec(CPUState *cpu)
{
ARMCPU *arm_cpu = ARM_CPU(cpu);
@@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
hv_return_t r;
int ret = 0;
-qemu_mutex_unlock_iothread();
-
do {
bool advance_pc = false;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_wait_io_event_common(cpu);
-qemu_mutex_unlock_iothread();
flush_cpu_state(cpu);
@@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
}
if (cpu->halted) {
-qemu_mutex_lock_iothread();
return EXCP_HLT;
}
+qemu_mutex_unlock_iothread();
assert_hvf_ok(hv_vcpu_run(cpu->hvf->fd));
/* handle VMEXIT */
@@ -385,15 +385,14 @@ int hvf_vcpu_exec(CPUState *cpu)
uint64_t syndrome = hvf_exit->exception.syndrome;
uint32_t ec = syn_get_ec(syndrome);
+qemu_mutex_lock_iothread();
switch (exit_reason) {
case HV_EXIT_REASON_EXCEPTION:
/* This is the main one, handle below. */
break;
case HV_EXIT_REASON_VTIMER_ACTIVATED:
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_set_irq(arm_cpu->gt_timer_outputs[GTIMER_VIRT], 1);
-qemu_mutex_unlock_iothread();
continue;
case HV_EXIT_REASON_CANCELED:
/* we got kicked, no exit to process */
@@ -413,7 +412,6 @@ int hvf_vcpu_exec(CPUState *cpu)
uint32_t srt = (syndrome >> 16) & 0x1f;
Re: [PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
On Tue, Dec 1, 2020 at 5:54 PM Alexander Graf wrote:
>
>
> On 02.12.20 02:52, Peter Collingbourne wrote:
> > On Tue, Dec 1, 2020 at 5:39 PM Alexander Graf wrote:
> >>
> >> On 02.12.20 02:32, Peter Collingbourne wrote:
> >>> On Tue, Dec 1, 2020 at 3:24 PM Alexander Graf wrote:
> On 01.12.20 22:00, Peter Collingbourne wrote:
> > Sleep on WFx until the VTIMER is due but allow ourselves to be woken
> > up on IPI.
> >
> > Signed-off-by: Peter Collingbourne
> > ---
> > v2:
> > - simplify locking further
> > - wait indefinitely on disabled or masked timers
> >
> > accel/hvf/hvf-cpus.c | 5 +-
> > include/sysemu/hvf_int.h | 3 +-
> > target/arm/hvf/hvf.c | 116
> > ++-
> > 3 files changed, 43 insertions(+), 81 deletions(-)
> >
> > diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
> > index 4360f64671..b2c8fb57f6 100644
> > --- a/accel/hvf/hvf-cpus.c
> > +++ b/accel/hvf/hvf-cpus.c
> > @@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
> > sigact.sa_handler = dummy_signal;
> > sigaction(SIG_IPI, , NULL);
> >
> > -pthread_sigmask(SIG_BLOCK, NULL, );
> > -sigdelset(, SIG_IPI);
> > -pthread_sigmask(SIG_SETMASK, , NULL);
> > +pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
> > +sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
> >
> > #ifdef __aarch64__
> > r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t
> > **)>hvf->exit, NULL);
> > diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
> > index c56baa3ae8..13adf6ea77 100644
> > --- a/include/sysemu/hvf_int.h
> > +++ b/include/sysemu/hvf_int.h
> > @@ -62,8 +62,7 @@ extern HVFState *hvf_state;
> > struct hvf_vcpu_state {
> > uint64_t fd;
> > void *exit;
> > -struct timespec ts;
> > -bool sleeping;
> > +sigset_t unblock_ipi_mask;
> > };
> >
> > void assert_hvf_ok(hv_return_t ret);
> > diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
> > index 8fe10966d2..3321d48aa2 100644
> > --- a/target/arm/hvf/hvf.c
> > +++ b/target/arm/hvf/hvf.c
> > @@ -2,6 +2,7 @@
> > * QEMU Hypervisor.framework support for Apple Silicon
> >
> > * Copyright 2020 Alexander Graf
> > + * Copyright 2020 Google LLC
> > *
> > * This work is licensed under the terms of the GNU GPL, version 2
> > or later.
> > * See the COPYING file in the top-level directory.
> > @@ -18,6 +19,7 @@
> > #include "sysemu/hw_accel.h"
> >
> > #include
> > +#include
> >
> > #include "exec/address-spaces.h"
> > #include "hw/irq.h"
> > @@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
> >
> > void hvf_kick_vcpu_thread(CPUState *cpu)
> > {
> > -if (cpu->hvf->sleeping) {
> > -/*
> > - * When sleeping, make sure we always send signals. Also,
> > clear the
> > - * timespec, so that an IPI that arrives between setting
> > hvf->sleeping
> > - * and the nanosleep syscall still aborts the sleep.
> > - */
> > -cpu->thread_kicked = false;
> > -cpu->hvf->ts = (struct timespec){ };
> > -cpus_kick_thread(cpu);
> > -} else {
> > -hv_vcpus_exit(>hvf->fd, 1);
> > -}
> > +cpus_kick_thread(cpu);
> > +hv_vcpus_exit(>hvf->fd, 1);
> > }
> >
> > static int hvf_inject_interrupts(CPUState *cpu)
> > @@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
> > return 0;
> > }
> >
> > +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_mb_set(>thread_kicked, false);
> > +qemu_mutex_unlock_iothread();
> > +pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
> > +qemu_mutex_lock_iothread();
> > +}
> > +
> > int hvf_vcpu_exec(CPUState *cpu)
> > {
> > ARMCPU *arm_cpu = ARM_CPU(cpu);
> > @@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
> > hv_return_t r;
> > int ret = 0;
> >
> > -qemu_mutex_unlock_iothread();
> > -
> > do {
> > bool advance_pc = false;
> >
> > -qemu_mutex_lock_iothread();
> > current_cpu = cpu;
> > qemu_wait_io_event_common(cpu);
> > -qemu_mutex_unlock_iothread();
> >
> > flush_cpu_state(cpu);
> >
> > @@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
> > }
> >
Re: [PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
On Tue, Dec 1, 2020 at 5:39 PM Alexander Graf wrote:
>
>
> On 02.12.20 02:32, Peter Collingbourne wrote:
> > On Tue, Dec 1, 2020 at 3:24 PM Alexander Graf wrote:
> >>
> >> On 01.12.20 22:00, Peter Collingbourne wrote:
> >>> Sleep on WFx until the VTIMER is due but allow ourselves to be woken
> >>> up on IPI.
> >>>
> >>> Signed-off-by: Peter Collingbourne
> >>> ---
> >>> v2:
> >>> - simplify locking further
> >>> - wait indefinitely on disabled or masked timers
> >>>
> >>>accel/hvf/hvf-cpus.c | 5 +-
> >>>include/sysemu/hvf_int.h | 3 +-
> >>>target/arm/hvf/hvf.c | 116 ++-
> >>>3 files changed, 43 insertions(+), 81 deletions(-)
> >>>
> >>> diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
> >>> index 4360f64671..b2c8fb57f6 100644
> >>> --- a/accel/hvf/hvf-cpus.c
> >>> +++ b/accel/hvf/hvf-cpus.c
> >>> @@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
> >>>sigact.sa_handler = dummy_signal;
> >>>sigaction(SIG_IPI, , NULL);
> >>>
> >>> -pthread_sigmask(SIG_BLOCK, NULL, );
> >>> -sigdelset(, SIG_IPI);
> >>> -pthread_sigmask(SIG_SETMASK, , NULL);
> >>> +pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
> >>> +sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
> >>>
> >>>#ifdef __aarch64__
> >>>r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t
> >>> **)>hvf->exit, NULL);
> >>> diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
> >>> index c56baa3ae8..13adf6ea77 100644
> >>> --- a/include/sysemu/hvf_int.h
> >>> +++ b/include/sysemu/hvf_int.h
> >>> @@ -62,8 +62,7 @@ extern HVFState *hvf_state;
> >>>struct hvf_vcpu_state {
> >>>uint64_t fd;
> >>>void *exit;
> >>> -struct timespec ts;
> >>> -bool sleeping;
> >>> +sigset_t unblock_ipi_mask;
> >>>};
> >>>
> >>>void assert_hvf_ok(hv_return_t ret);
> >>> diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
> >>> index 8fe10966d2..3321d48aa2 100644
> >>> --- a/target/arm/hvf/hvf.c
> >>> +++ b/target/arm/hvf/hvf.c
> >>> @@ -2,6 +2,7 @@
> >>> * QEMU Hypervisor.framework support for Apple Silicon
> >>>
> >>> * Copyright 2020 Alexander Graf
> >>> + * Copyright 2020 Google LLC
> >>> *
> >>> * This work is licensed under the terms of the GNU GPL, version 2 or
> >>> later.
> >>> * See the COPYING file in the top-level directory.
> >>> @@ -18,6 +19,7 @@
> >>>#include "sysemu/hw_accel.h"
> >>>
> >>>#include
> >>> +#include
> >>>
> >>>#include "exec/address-spaces.h"
> >>>#include "hw/irq.h"
> >>> @@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
> >>>
> >>>void hvf_kick_vcpu_thread(CPUState *cpu)
> >>>{
> >>> -if (cpu->hvf->sleeping) {
> >>> -/*
> >>> - * When sleeping, make sure we always send signals. Also, clear
> >>> the
> >>> - * timespec, so that an IPI that arrives between setting
> >>> hvf->sleeping
> >>> - * and the nanosleep syscall still aborts the sleep.
> >>> - */
> >>> -cpu->thread_kicked = false;
> >>> -cpu->hvf->ts = (struct timespec){ };
> >>> -cpus_kick_thread(cpu);
> >>> -} else {
> >>> -hv_vcpus_exit(>hvf->fd, 1);
> >>> -}
> >>> +cpus_kick_thread(cpu);
> >>> +hv_vcpus_exit(>hvf->fd, 1);
> >>>}
> >>>
> >>>static int hvf_inject_interrupts(CPUState *cpu)
> >>> @@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
> >>>return 0;
> >>>}
> >>>
> >>> +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_mb_set(>thread_kicked, false);
> >>> +qemu_mutex_unlock_iothread();
> >>> +pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
> >>> +qemu_mutex_lock_iothread();
> >>> +}
> >>> +
> >>>int hvf_vcpu_exec(CPUState *cpu)
> >>>{
> >>>ARMCPU *arm_cpu = ARM_CPU(cpu);
> >>> @@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
> >>>hv_return_t r;
> >>>int ret = 0;
> >>>
> >>> -qemu_mutex_unlock_iothread();
> >>> -
> >>>do {
> >>>bool advance_pc = false;
> >>>
> >>> -qemu_mutex_lock_iothread();
> >>>current_cpu = cpu;
> >>>qemu_wait_io_event_common(cpu);
> >>> -qemu_mutex_unlock_iothread();
> >>>
> >>>flush_cpu_state(cpu);
> >>>
> >>> @@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
> >>>}
> >>>
> >>>if (cpu->halted) {
> >>> -qemu_mutex_lock_iothread();
> >>>return EXCP_HLT;
> >>>}
> >>>
> >>> +qemu_mutex_unlock_iothread();
> >>>assert_hvf_ok(hv_vcpu_run(cpu->hvf->fd));
> >>>
> >>>/* handle VMEXIT */
> >>> @@ -385,15 +385,14 @@ int hvf_vcpu_exec(CPUState *cpu)
> >>>uint64_t syndrome = hvf_exit->exception.syndrome;
>
Re: [PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
On 02.12.20 02:32, Peter Collingbourne wrote:
On Tue, Dec 1, 2020 at 3:24 PM Alexander Graf wrote:
On 01.12.20 22:00, Peter Collingbourne wrote:
Sleep on WFx until the VTIMER is due but allow ourselves to be woken
up on IPI.
Signed-off-by: Peter Collingbourne
---
v2:
- simplify locking further
- wait indefinitely on disabled or masked timers
accel/hvf/hvf-cpus.c | 5 +-
include/sysemu/hvf_int.h | 3 +-
target/arm/hvf/hvf.c | 116 ++-
3 files changed, 43 insertions(+), 81 deletions(-)
diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
index 4360f64671..b2c8fb57f6 100644
--- a/accel/hvf/hvf-cpus.c
+++ b/accel/hvf/hvf-cpus.c
@@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
sigact.sa_handler = dummy_signal;
sigaction(SIG_IPI, , NULL);
-pthread_sigmask(SIG_BLOCK, NULL, );
-sigdelset(, SIG_IPI);
-pthread_sigmask(SIG_SETMASK, , NULL);
+pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
+sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
#ifdef __aarch64__
r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t **)>hvf->exit,
NULL);
diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
index c56baa3ae8..13adf6ea77 100644
--- a/include/sysemu/hvf_int.h
+++ b/include/sysemu/hvf_int.h
@@ -62,8 +62,7 @@ extern HVFState *hvf_state;
struct hvf_vcpu_state {
uint64_t fd;
void *exit;
-struct timespec ts;
-bool sleeping;
+sigset_t unblock_ipi_mask;
};
void assert_hvf_ok(hv_return_t ret);
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 8fe10966d2..3321d48aa2 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -2,6 +2,7 @@
* QEMU Hypervisor.framework support for Apple Silicon
* Copyright 2020 Alexander Graf
+ * Copyright 2020 Google LLC
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
@@ -18,6 +19,7 @@
#include "sysemu/hw_accel.h"
#include
+#include
#include "exec/address-spaces.h"
#include "hw/irq.h"
@@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
void hvf_kick_vcpu_thread(CPUState *cpu)
{
-if (cpu->hvf->sleeping) {
-/*
- * When sleeping, make sure we always send signals. Also, clear the
- * timespec, so that an IPI that arrives between setting hvf->sleeping
- * and the nanosleep syscall still aborts the sleep.
- */
-cpu->thread_kicked = false;
-cpu->hvf->ts = (struct timespec){ };
-cpus_kick_thread(cpu);
-} else {
-hv_vcpus_exit(>hvf->fd, 1);
-}
+cpus_kick_thread(cpu);
+hv_vcpus_exit(>hvf->fd, 1);
}
static int hvf_inject_interrupts(CPUState *cpu)
@@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
return 0;
}
+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_mb_set(>thread_kicked, false);
+qemu_mutex_unlock_iothread();
+pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
+qemu_mutex_lock_iothread();
+}
+
int hvf_vcpu_exec(CPUState *cpu)
{
ARMCPU *arm_cpu = ARM_CPU(cpu);
@@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
hv_return_t r;
int ret = 0;
-qemu_mutex_unlock_iothread();
-
do {
bool advance_pc = false;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_wait_io_event_common(cpu);
-qemu_mutex_unlock_iothread();
flush_cpu_state(cpu);
@@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
}
if (cpu->halted) {
-qemu_mutex_lock_iothread();
return EXCP_HLT;
}
+qemu_mutex_unlock_iothread();
assert_hvf_ok(hv_vcpu_run(cpu->hvf->fd));
/* handle VMEXIT */
@@ -385,15 +385,14 @@ int hvf_vcpu_exec(CPUState *cpu)
uint64_t syndrome = hvf_exit->exception.syndrome;
uint32_t ec = syn_get_ec(syndrome);
+qemu_mutex_lock_iothread();
switch (exit_reason) {
case HV_EXIT_REASON_EXCEPTION:
/* This is the main one, handle below. */
break;
case HV_EXIT_REASON_VTIMER_ACTIVATED:
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_set_irq(arm_cpu->gt_timer_outputs[GTIMER_VIRT], 1);
-qemu_mutex_unlock_iothread();
continue;
case HV_EXIT_REASON_CANCELED:
/* we got kicked, no exit to process */
@@ -413,7 +412,6 @@ int hvf_vcpu_exec(CPUState *cpu)
uint32_t srt = (syndrome >> 16) & 0x1f;
uint64_t val = 0;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
DPRINTF("data abort: [pc=0x%llx va=0x%016llx
Re: [PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
On Tue, Dec 1, 2020 at 3:24 PM Alexander Graf wrote:
>
>
> On 01.12.20 22:00, Peter Collingbourne wrote:
> > Sleep on WFx until the VTIMER is due but allow ourselves to be woken
> > up on IPI.
> >
> > Signed-off-by: Peter Collingbourne
> > ---
> > v2:
> > - simplify locking further
> > - wait indefinitely on disabled or masked timers
> >
> > accel/hvf/hvf-cpus.c | 5 +-
> > include/sysemu/hvf_int.h | 3 +-
> > target/arm/hvf/hvf.c | 116 ++-
> > 3 files changed, 43 insertions(+), 81 deletions(-)
> >
> > diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
> > index 4360f64671..b2c8fb57f6 100644
> > --- a/accel/hvf/hvf-cpus.c
> > +++ b/accel/hvf/hvf-cpus.c
> > @@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
> > sigact.sa_handler = dummy_signal;
> > sigaction(SIG_IPI, , NULL);
> >
> > -pthread_sigmask(SIG_BLOCK, NULL, );
> > -sigdelset(, SIG_IPI);
> > -pthread_sigmask(SIG_SETMASK, , NULL);
> > +pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
> > +sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
> >
> > #ifdef __aarch64__
> > r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t **)>hvf->exit,
> > NULL);
> > diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
> > index c56baa3ae8..13adf6ea77 100644
> > --- a/include/sysemu/hvf_int.h
> > +++ b/include/sysemu/hvf_int.h
> > @@ -62,8 +62,7 @@ extern HVFState *hvf_state;
> > struct hvf_vcpu_state {
> > uint64_t fd;
> > void *exit;
> > -struct timespec ts;
> > -bool sleeping;
> > +sigset_t unblock_ipi_mask;
> > };
> >
> > void assert_hvf_ok(hv_return_t ret);
> > diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
> > index 8fe10966d2..3321d48aa2 100644
> > --- a/target/arm/hvf/hvf.c
> > +++ b/target/arm/hvf/hvf.c
> > @@ -2,6 +2,7 @@
> >* QEMU Hypervisor.framework support for Apple Silicon
> >
> >* Copyright 2020 Alexander Graf
> > + * Copyright 2020 Google LLC
> >*
> >* This work is licensed under the terms of the GNU GPL, version 2 or
> > later.
> >* See the COPYING file in the top-level directory.
> > @@ -18,6 +19,7 @@
> > #include "sysemu/hw_accel.h"
> >
> > #include
> > +#include
> >
> > #include "exec/address-spaces.h"
> > #include "hw/irq.h"
> > @@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
> >
> > void hvf_kick_vcpu_thread(CPUState *cpu)
> > {
> > -if (cpu->hvf->sleeping) {
> > -/*
> > - * When sleeping, make sure we always send signals. Also, clear the
> > - * timespec, so that an IPI that arrives between setting
> > hvf->sleeping
> > - * and the nanosleep syscall still aborts the sleep.
> > - */
> > -cpu->thread_kicked = false;
> > -cpu->hvf->ts = (struct timespec){ };
> > -cpus_kick_thread(cpu);
> > -} else {
> > -hv_vcpus_exit(>hvf->fd, 1);
> > -}
> > +cpus_kick_thread(cpu);
> > +hv_vcpus_exit(>hvf->fd, 1);
> > }
> >
> > static int hvf_inject_interrupts(CPUState *cpu)
> > @@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
> > return 0;
> > }
> >
> > +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_mb_set(>thread_kicked, false);
> > +qemu_mutex_unlock_iothread();
> > +pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
> > +qemu_mutex_lock_iothread();
> > +}
> > +
> > int hvf_vcpu_exec(CPUState *cpu)
> > {
> > ARMCPU *arm_cpu = ARM_CPU(cpu);
> > @@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
> > hv_return_t r;
> > int ret = 0;
> >
> > -qemu_mutex_unlock_iothread();
> > -
> > do {
> > bool advance_pc = false;
> >
> > -qemu_mutex_lock_iothread();
> > current_cpu = cpu;
> > qemu_wait_io_event_common(cpu);
> > -qemu_mutex_unlock_iothread();
> >
> > flush_cpu_state(cpu);
> >
> > @@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
> > }
> >
> > if (cpu->halted) {
> > -qemu_mutex_lock_iothread();
> > return EXCP_HLT;
> > }
> >
> > +qemu_mutex_unlock_iothread();
> > assert_hvf_ok(hv_vcpu_run(cpu->hvf->fd));
> >
> > /* handle VMEXIT */
> > @@ -385,15 +385,14 @@ int hvf_vcpu_exec(CPUState *cpu)
> > uint64_t syndrome = hvf_exit->exception.syndrome;
> > uint32_t ec = syn_get_ec(syndrome);
> >
> > +qemu_mutex_lock_iothread();
> > switch (exit_reason) {
> > case HV_EXIT_REASON_EXCEPTION:
> > /* This is the main one, handle below. */
> > break;
> > case HV_EXIT_REASON_VTIMER_ACTIVATED:
> > -qemu_mutex_lock_iothread();
> > current_cpu = cpu;
> >
Re: [PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
On 01.12.20 22:00, Peter Collingbourne wrote:
Sleep on WFx until the VTIMER is due but allow ourselves to be woken
up on IPI.
Signed-off-by: Peter Collingbourne
---
v2:
- simplify locking further
- wait indefinitely on disabled or masked timers
accel/hvf/hvf-cpus.c | 5 +-
include/sysemu/hvf_int.h | 3 +-
target/arm/hvf/hvf.c | 116 ++-
3 files changed, 43 insertions(+), 81 deletions(-)
diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
index 4360f64671..b2c8fb57f6 100644
--- a/accel/hvf/hvf-cpus.c
+++ b/accel/hvf/hvf-cpus.c
@@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
sigact.sa_handler = dummy_signal;
sigaction(SIG_IPI, , NULL);
-pthread_sigmask(SIG_BLOCK, NULL, );
-sigdelset(, SIG_IPI);
-pthread_sigmask(SIG_SETMASK, , NULL);
+pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
+sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
#ifdef __aarch64__
r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t **)>hvf->exit,
NULL);
diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
index c56baa3ae8..13adf6ea77 100644
--- a/include/sysemu/hvf_int.h
+++ b/include/sysemu/hvf_int.h
@@ -62,8 +62,7 @@ extern HVFState *hvf_state;
struct hvf_vcpu_state {
uint64_t fd;
void *exit;
-struct timespec ts;
-bool sleeping;
+sigset_t unblock_ipi_mask;
};
void assert_hvf_ok(hv_return_t ret);
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 8fe10966d2..3321d48aa2 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -2,6 +2,7 @@
* QEMU Hypervisor.framework support for Apple Silicon
* Copyright 2020 Alexander Graf
+ * Copyright 2020 Google LLC
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
@@ -18,6 +19,7 @@
#include "sysemu/hw_accel.h"
#include
+#include
#include "exec/address-spaces.h"
#include "hw/irq.h"
@@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
void hvf_kick_vcpu_thread(CPUState *cpu)
{
-if (cpu->hvf->sleeping) {
-/*
- * When sleeping, make sure we always send signals. Also, clear the
- * timespec, so that an IPI that arrives between setting hvf->sleeping
- * and the nanosleep syscall still aborts the sleep.
- */
-cpu->thread_kicked = false;
-cpu->hvf->ts = (struct timespec){ };
-cpus_kick_thread(cpu);
-} else {
-hv_vcpus_exit(>hvf->fd, 1);
-}
+cpus_kick_thread(cpu);
+hv_vcpus_exit(>hvf->fd, 1);
}
static int hvf_inject_interrupts(CPUState *cpu)
@@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
return 0;
}
+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_mb_set(>thread_kicked, false);
+qemu_mutex_unlock_iothread();
+pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
+qemu_mutex_lock_iothread();
+}
+
int hvf_vcpu_exec(CPUState *cpu)
{
ARMCPU *arm_cpu = ARM_CPU(cpu);
@@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
hv_return_t r;
int ret = 0;
-qemu_mutex_unlock_iothread();
-
do {
bool advance_pc = false;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_wait_io_event_common(cpu);
-qemu_mutex_unlock_iothread();
flush_cpu_state(cpu);
@@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
}
if (cpu->halted) {
-qemu_mutex_lock_iothread();
return EXCP_HLT;
}
+qemu_mutex_unlock_iothread();
assert_hvf_ok(hv_vcpu_run(cpu->hvf->fd));
/* handle VMEXIT */
@@ -385,15 +385,14 @@ int hvf_vcpu_exec(CPUState *cpu)
uint64_t syndrome = hvf_exit->exception.syndrome;
uint32_t ec = syn_get_ec(syndrome);
+qemu_mutex_lock_iothread();
switch (exit_reason) {
case HV_EXIT_REASON_EXCEPTION:
/* This is the main one, handle below. */
break;
case HV_EXIT_REASON_VTIMER_ACTIVATED:
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_set_irq(arm_cpu->gt_timer_outputs[GTIMER_VIRT], 1);
-qemu_mutex_unlock_iothread();
continue;
case HV_EXIT_REASON_CANCELED:
/* we got kicked, no exit to process */
@@ -413,7 +412,6 @@ int hvf_vcpu_exec(CPUState *cpu)
uint32_t srt = (syndrome >> 16) & 0x1f;
uint64_t val = 0;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
DPRINTF("data abort: [pc=0x%llx va=0x%016llx pa=0x%016llx isv=%x "
@@ -446,8 +444,6 @@ int hvf_vcpu_exec(CPUState *cpu)
hvf_set_reg(cpu,
[PATCH v2 1/2] arm/hvf: Optimize and simplify WFI handling
Sleep on WFx until the VTIMER is due but allow ourselves to be woken
up on IPI.
Signed-off-by: Peter Collingbourne
---
v2:
- simplify locking further
- wait indefinitely on disabled or masked timers
accel/hvf/hvf-cpus.c | 5 +-
include/sysemu/hvf_int.h | 3 +-
target/arm/hvf/hvf.c | 116 ++-
3 files changed, 43 insertions(+), 81 deletions(-)
diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
index 4360f64671..b2c8fb57f6 100644
--- a/accel/hvf/hvf-cpus.c
+++ b/accel/hvf/hvf-cpus.c
@@ -344,9 +344,8 @@ static int hvf_init_vcpu(CPUState *cpu)
sigact.sa_handler = dummy_signal;
sigaction(SIG_IPI, , NULL);
-pthread_sigmask(SIG_BLOCK, NULL, );
-sigdelset(, SIG_IPI);
-pthread_sigmask(SIG_SETMASK, , NULL);
+pthread_sigmask(SIG_BLOCK, NULL, >hvf->unblock_ipi_mask);
+sigdelset(>hvf->unblock_ipi_mask, SIG_IPI);
#ifdef __aarch64__
r = hv_vcpu_create(>hvf->fd, (hv_vcpu_exit_t **)>hvf->exit,
NULL);
diff --git a/include/sysemu/hvf_int.h b/include/sysemu/hvf_int.h
index c56baa3ae8..13adf6ea77 100644
--- a/include/sysemu/hvf_int.h
+++ b/include/sysemu/hvf_int.h
@@ -62,8 +62,7 @@ extern HVFState *hvf_state;
struct hvf_vcpu_state {
uint64_t fd;
void *exit;
-struct timespec ts;
-bool sleeping;
+sigset_t unblock_ipi_mask;
};
void assert_hvf_ok(hv_return_t ret);
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 8fe10966d2..3321d48aa2 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -2,6 +2,7 @@
* QEMU Hypervisor.framework support for Apple Silicon
* Copyright 2020 Alexander Graf
+ * Copyright 2020 Google LLC
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
@@ -18,6 +19,7 @@
#include "sysemu/hw_accel.h"
#include
+#include
#include "exec/address-spaces.h"
#include "hw/irq.h"
@@ -320,18 +322,8 @@ int hvf_arch_init_vcpu(CPUState *cpu)
void hvf_kick_vcpu_thread(CPUState *cpu)
{
-if (cpu->hvf->sleeping) {
-/*
- * When sleeping, make sure we always send signals. Also, clear the
- * timespec, so that an IPI that arrives between setting hvf->sleeping
- * and the nanosleep syscall still aborts the sleep.
- */
-cpu->thread_kicked = false;
-cpu->hvf->ts = (struct timespec){ };
-cpus_kick_thread(cpu);
-} else {
-hv_vcpus_exit(>hvf->fd, 1);
-}
+cpus_kick_thread(cpu);
+hv_vcpus_exit(>hvf->fd, 1);
}
static int hvf_inject_interrupts(CPUState *cpu)
@@ -349,6 +341,18 @@ static int hvf_inject_interrupts(CPUState *cpu)
return 0;
}
+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_mb_set(>thread_kicked, false);
+qemu_mutex_unlock_iothread();
+pselect(0, 0, 0, 0, ts, >hvf->unblock_ipi_mask);
+qemu_mutex_lock_iothread();
+}
+
int hvf_vcpu_exec(CPUState *cpu)
{
ARMCPU *arm_cpu = ARM_CPU(cpu);
@@ -357,15 +361,11 @@ int hvf_vcpu_exec(CPUState *cpu)
hv_return_t r;
int ret = 0;
-qemu_mutex_unlock_iothread();
-
do {
bool advance_pc = false;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_wait_io_event_common(cpu);
-qemu_mutex_unlock_iothread();
flush_cpu_state(cpu);
@@ -374,10 +374,10 @@ int hvf_vcpu_exec(CPUState *cpu)
}
if (cpu->halted) {
-qemu_mutex_lock_iothread();
return EXCP_HLT;
}
+qemu_mutex_unlock_iothread();
assert_hvf_ok(hv_vcpu_run(cpu->hvf->fd));
/* handle VMEXIT */
@@ -385,15 +385,14 @@ int hvf_vcpu_exec(CPUState *cpu)
uint64_t syndrome = hvf_exit->exception.syndrome;
uint32_t ec = syn_get_ec(syndrome);
+qemu_mutex_lock_iothread();
switch (exit_reason) {
case HV_EXIT_REASON_EXCEPTION:
/* This is the main one, handle below. */
break;
case HV_EXIT_REASON_VTIMER_ACTIVATED:
-qemu_mutex_lock_iothread();
current_cpu = cpu;
qemu_set_irq(arm_cpu->gt_timer_outputs[GTIMER_VIRT], 1);
-qemu_mutex_unlock_iothread();
continue;
case HV_EXIT_REASON_CANCELED:
/* we got kicked, no exit to process */
@@ -413,7 +412,6 @@ int hvf_vcpu_exec(CPUState *cpu)
uint32_t srt = (syndrome >> 16) & 0x1f;
uint64_t val = 0;
-qemu_mutex_lock_iothread();
current_cpu = cpu;
DPRINTF("data abort: [pc=0x%llx va=0x%016llx pa=0x%016llx isv=%x "
@@ -446,8 +444,6 @@ int hvf_vcpu_exec(CPUState *cpu)
hvf_set_reg(cpu, srt, val);
}
-qemu_mutex_unlock_iothread();
-
advance_pc = true;
break;
}
@@ -493,68
