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Re: [Qemu-ppc] [PATCH v8 08/25] tcg: drop global lock during TCG code ex
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From: |
Alex Bennée |
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Subject: |
Re: [Qemu-ppc] [PATCH v8 08/25] tcg: drop global lock during TCG code execution |
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Date: |
Mon, 30 Jan 2017 09:57:08 +0000 |
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User-agent: |
mu4e 0.9.19; emacs 25.1.91.6 |
Pranith Kumar <address@hidden> writes:
> Alex Bennée writes:
>
>> From: Jan Kiszka <address@hidden>
>>
>> This finally allows TCG to benefit from the iothread introduction: Drop
>> the global mutex while running pure TCG CPU code. Reacquire the lock
>> when entering MMIO or PIO emulation, or when leaving the TCG loop.
>>
>> We have to revert a few optimization for the current TCG threading
>> model, namely kicking the TCG thread in qemu_mutex_lock_iothread and not
>> kicking it in qemu_cpu_kick. We also need to disable RAM block
>> reordering until we have a more efficient locking mechanism at hand.
>>
>> Still, a Linux x86 UP guest and my Musicpal ARM model boot fine here.
>> These numbers demonstrate where we gain something:
>>
>> 20338 jan 20 0 331m 75m 6904 R 99 0.9 0:50.95 qemu-system-arm
>> 20337 jan 20 0 331m 75m 6904 S 20 0.9 0:26.50 qemu-system-arm
>>
>> The guest CPU was fully loaded, but the iothread could still run mostly
>> independent on a second core. Without the patch we don't get beyond
>>
>> 32206 jan 20 0 330m 73m 7036 R 82 0.9 1:06.00 qemu-system-arm
>> 32204 jan 20 0 330m 73m 7036 S 21 0.9 0:17.03 qemu-system-arm
>>
>> We don't benefit significantly, though, when the guest is not fully
>> loading a host CPU.
>>
>> Signed-off-by: Jan Kiszka <address@hidden>
>> Message-Id: <address@hidden>
>> [FK: Rebase, fix qemu_devices_reset deadlock, rm address_space_* mutex]
>> Signed-off-by: KONRAD Frederic <address@hidden>
>> [EGC: fixed iothread lock for cpu-exec IRQ handling]
>> Signed-off-by: Emilio G. Cota <address@hidden>
>> [AJB: -smp single-threaded fix, clean commit msg, BQL fixes]
>> Signed-off-by: Alex Bennée <address@hidden>
>> Reviewed-by: Richard Henderson <address@hidden>
>>
>> ---
>> v8:
>> - merged in BQL fixes for PPC target: ppc_set_irq
>> - merged in BQL fixes for ARM target: ARM_CP_IO helpers
>> - merged in BQL fixes for ARM target: arm_call_el_change_hook
>>
>> v5 (ajb, base patches):
>> - added an assert to BQL unlock/lock functions instead of hanging
>> - ensure all cpu->interrupt_requests *modifications* protected by BQL
>> - add a re-read on cpu->interrupt_request for correctness
>> - BQL fixes for:
>> - assert BQL held for PPC hypercalls (emulate_spar_hypercall)
>> - SCLP service calls on s390x
>> - merge conflict with kick timer patch
>> v4 (ajb, base patches):
>> - protect cpu->interrupt updates with BQL
>> - fix wording io_mem_notdirty calls
>> - s/we/with/
>> v3 (ajb, base-patches):
>> - stale iothread_unlocks removed (cpu_exit/resume_from_signal deals
>> with it in the longjmp).
>> - fix re-base conflicts
>> v2 (ajb):
>> - merge with tcg: grab iothread lock in cpu-exec interrupt handling
>> - use existing fns for tracking lock state
>> - lock iothread for mem_region
>> - add assert on mem region modification
>> - ensure smm_helper holds iothread
>> - Add JK s-o-b
>> - Fix-up FK s-o-b annotation
>> v1 (ajb, base-patches):
>> - SMP failure now fixed by previous commit
>>
>> Changes from Fred Konrad (mttcg-v7 via paolo):
>> * Rebase on the current HEAD.
>> * Fixes a deadlock in qemu_devices_reset().
>> * Remove the mutex in address_space_*
>> ---
>> cpu-exec.c | 20 ++++++++++++++++++--
>> cpus.c | 28 +++++-----------------------
>> cputlb.c | 21 ++++++++++++++++++++-
>> exec.c | 12 +++++++++---
>> hw/core/irq.c | 1 +
>> hw/i386/kvmvapic.c | 4 ++--
>> hw/intc/arm_gicv3_cpuif.c | 3 +++
>> hw/ppc/ppc.c | 16 +++++++++++++++-
>> hw/ppc/spapr.c | 3 +++
>> include/qom/cpu.h | 1 +
>> memory.c | 2 ++
>> qom/cpu.c | 10 ++++++++++
>> target/arm/helper.c | 6 ++++++
>> target/arm/op_helper.c | 43 +++++++++++++++++++++++++++++++++++++++----
>> target/i386/smm_helper.c | 7 +++++++
>> target/s390x/misc_helper.c | 5 ++++-
>> translate-all.c | 9 +++++++--
>> translate-common.c | 21 +++++++++++----------
>> 18 files changed, 163 insertions(+), 49 deletions(-)
>>
>> diff --git a/cpu-exec.c b/cpu-exec.c
>> index f9e836c8dd..f42a128bdf 100644
>> --- a/cpu-exec.c
>> +++ b/cpu-exec.c
>> @@ -29,6 +29,7 @@
>> #include "qemu/rcu.h"
>> #include "exec/tb-hash.h"
>> #include "exec/log.h"
>> +#include "qemu/main-loop.h"
>> #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
>> #include "hw/i386/apic.h"
>> #endif
>> @@ -388,8 +389,10 @@ static inline bool cpu_handle_halt(CPUState *cpu)
>> if ((cpu->interrupt_request & CPU_INTERRUPT_POLL)
>> && replay_interrupt()) {
>> X86CPU *x86_cpu = X86_CPU(cpu);
>> + qemu_mutex_lock_iothread();
>> apic_poll_irq(x86_cpu->apic_state);
>> cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
>> + qemu_mutex_unlock_iothread();
>> }
>> #endif
>> if (!cpu_has_work(cpu)) {
>> @@ -443,7 +446,9 @@ static inline bool cpu_handle_exception(CPUState *cpu,
>> int *ret)
>> #else
>> if (replay_exception()) {
>> CPUClass *cc = CPU_GET_CLASS(cpu);
>> + qemu_mutex_lock_iothread();
>> cc->do_interrupt(cpu);
>> + qemu_mutex_unlock_iothread();
>> cpu->exception_index = -1;
>> } else if (!replay_has_interrupt()) {
>> /* give a chance to iothread in replay mode */
>> @@ -469,9 +474,11 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
>> TranslationBlock **last_tb)
>> {
>> CPUClass *cc = CPU_GET_CLASS(cpu);
>> - int interrupt_request = cpu->interrupt_request;
>>
>> - if (unlikely(interrupt_request)) {
>> + if (unlikely(atomic_read(&cpu->interrupt_request))) {
>> + int interrupt_request;
>> + qemu_mutex_lock_iothread();
>> + interrupt_request = cpu->interrupt_request;
>> if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
>> /* Mask out external interrupts for this step. */
>> interrupt_request &= ~CPU_INTERRUPT_SSTEP_MASK;
>> @@ -526,7 +533,12 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
>> the program flow was changed */
>> *last_tb = NULL;
>> }
>> +
>> + /* If we exit via cpu_loop_exit/longjmp it is reset in cpu_exec */
>> + qemu_mutex_unlock_iothread();
>> }
>> +
>> +
>> if (unlikely(atomic_read(&cpu->exit_request) ||
>> replay_has_interrupt())) {
>> atomic_set(&cpu->exit_request, 0);
>> cpu->exception_index = EXCP_INTERRUPT;
>> @@ -656,8 +668,12 @@ int cpu_exec(CPUState *cpu)
>> g_assert(cpu == current_cpu);
>> g_assert(cc == CPU_GET_CLASS(cpu));
>> #endif /* buggy compiler */
>> +
>> cpu->can_do_io = 1;
>> tb_lock_reset();
>> + if (qemu_mutex_iothread_locked()) {
>> + qemu_mutex_unlock_iothread();
>> + }
>> }
>> } /* for(;;) */
>>
>> diff --git a/cpus.c b/cpus.c
>> index 6d64199831..c48bc8d5b3 100644
>> --- a/cpus.c
>> +++ b/cpus.c
>> @@ -1026,8 +1026,6 @@ static void qemu_kvm_init_cpu_signals(CPUState *cpu)
>> #endif /* _WIN32 */
>>
>> static QemuMutex qemu_global_mutex;
>> -static QemuCond qemu_io_proceeded_cond;
>> -static unsigned iothread_requesting_mutex;
>>
>> static QemuThread io_thread;
>>
>> @@ -1041,7 +1039,6 @@ void qemu_init_cpu_loop(void)
>> qemu_init_sigbus();
>> qemu_cond_init(&qemu_cpu_cond);
>> qemu_cond_init(&qemu_pause_cond);
>> - qemu_cond_init(&qemu_io_proceeded_cond);
>> qemu_mutex_init(&qemu_global_mutex);
>>
>> qemu_thread_get_self(&io_thread);
>> @@ -1084,10 +1081,6 @@ static void qemu_tcg_wait_io_event(CPUState *cpu)
>>
>> start_tcg_kick_timer();
>>
>> - while (iothread_requesting_mutex) {
>> - qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex);
>> - }
>> -
>> CPU_FOREACH(cpu) {
>> qemu_wait_io_event_common(cpu);
>> }
>> @@ -1248,9 +1241,11 @@ static int tcg_cpu_exec(CPUState *cpu)
>> cpu->icount_decr.u16.low = decr;
>> cpu->icount_extra = count;
>> }
>> + qemu_mutex_unlock_iothread();
>> cpu_exec_start(cpu);
>> ret = cpu_exec(cpu);
>> cpu_exec_end(cpu);
>> + qemu_mutex_lock_iothread();
>> #ifdef CONFIG_PROFILER
>> tcg_time += profile_getclock() - ti;
>> #endif
>> @@ -1478,27 +1473,14 @@ bool qemu_mutex_iothread_locked(void)
>>
>> void qemu_mutex_lock_iothread(void)
>> {
>> - atomic_inc(&iothread_requesting_mutex);
>> - /* In the simple case there is no need to bump the VCPU thread out of
>> - * TCG code execution.
>> - */
>> - if (!tcg_enabled() || qemu_in_vcpu_thread() ||
>> - !first_cpu || !first_cpu->created) {
>> - qemu_mutex_lock(&qemu_global_mutex);
>> - atomic_dec(&iothread_requesting_mutex);
>> - } else {
>> - if (qemu_mutex_trylock(&qemu_global_mutex)) {
>> - qemu_cpu_kick_rr_cpu();
>> - qemu_mutex_lock(&qemu_global_mutex);
>> - }
>> - atomic_dec(&iothread_requesting_mutex);
>> - qemu_cond_broadcast(&qemu_io_proceeded_cond);
>> - }
>> + g_assert(!qemu_mutex_iothread_locked());
>
> How about using tcg_debug_assert here...
>
>> + qemu_mutex_lock(&qemu_global_mutex);
>> iothread_locked = true;
>> }
>>
>> void qemu_mutex_unlock_iothread(void)
>> {
>> + g_assert(qemu_mutex_iothread_locked());
>
> ... and here?
The iothread mutex is widely used in QEMU for bits other than TCG. In
fact I think it was introduced when KVM support was merged. As such I
don't want to remove these asserts from KVM mode.
It does mean this patch is slowly accreteing fixes for the BQL being
taken up by system emulation code though.
>
>> iothread_locked = false;
>> qemu_mutex_unlock(&qemu_global_mutex);
>> }
>> diff --git a/cputlb.c b/cputlb.c
>> index 6c39927455..1cc9d9da51 100644
>> --- a/cputlb.c
>> +++ b/cputlb.c
>> @@ -18,6 +18,7 @@
>> */
>>
>> #include "qemu/osdep.h"
>> +#include "qemu/main-loop.h"
>> #include "cpu.h"
>> #include "exec/exec-all.h"
>> #include "exec/memory.h"
>> @@ -495,6 +496,7 @@ static uint64_t io_readx(CPUArchState *env,
>> CPUIOTLBEntry *iotlbentry,
>> hwaddr physaddr = iotlbentry->addr;
>> MemoryRegion *mr = iotlb_to_region(cpu, physaddr, iotlbentry->attrs);
>> uint64_t val;
>> + bool locked = false;
>>
>> physaddr = (physaddr & TARGET_PAGE_MASK) + addr;
>> cpu->mem_io_pc = retaddr;
>> @@ -503,7 +505,16 @@ static uint64_t io_readx(CPUArchState *env,
>> CPUIOTLBEntry *iotlbentry,
>> }
>>
>> cpu->mem_io_vaddr = addr;
>> +
>> + if (mr->global_locking) {
>> + qemu_mutex_lock_iothread();
>> + locked = true;
>> + }
>> memory_region_dispatch_read(mr, physaddr, &val, size,
>> iotlbentry->attrs);
>> + if (locked) {
>> + qemu_mutex_unlock_iothread();
>> + }
>> +
>> return val;
>> }
>>
>> @@ -514,15 +525,23 @@ static void io_writex(CPUArchState *env, CPUIOTLBEntry
>> *iotlbentry,
>> CPUState *cpu = ENV_GET_CPU(env);
>> hwaddr physaddr = iotlbentry->addr;
>> MemoryRegion *mr = iotlb_to_region(cpu, physaddr, iotlbentry->attrs);
>> + bool locked = false;
>>
>> physaddr = (physaddr & TARGET_PAGE_MASK) + addr;
>> if (mr != &io_mem_rom && mr != &io_mem_notdirty && !cpu->can_do_io) {
>> cpu_io_recompile(cpu, retaddr);
>> }
>> -
>
> I am not really opposed but, I like having this line.. not sure why
> you are removing it? :)
Over zealous whitespace trimming, I can put it back ;-)
>
>> cpu->mem_io_vaddr = addr;
>> cpu->mem_io_pc = retaddr;
>> +
>> + if (mr->global_locking) {
>> + qemu_mutex_lock_iothread();
>> + locked = true;
>> + }
>> memory_region_dispatch_write(mr, physaddr, val, size,
>> iotlbentry->attrs);
>> + if (locked) {
>> + qemu_mutex_unlock_iothread();
>> + }
>> }
>>
>> /* Return true if ADDR is present in the victim tlb, and has been copied
>> diff --git a/exec.c b/exec.c
>> index f2bed92b64..87cf0db91e 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -2133,9 +2133,9 @@ static void check_watchpoint(int offset, int len,
>> MemTxAttrs attrs, int flags)
>> }
>> cpu->watchpoint_hit = wp;
>>
>> - /* The tb_lock will be reset when cpu_loop_exit or
>> - * cpu_loop_exit_noexc longjmp back into the cpu_exec
>> - * main loop.
>> + /* Both tb_lock and iothread_mutex will be reset when
>> + * cpu_loop_exit or cpu_loop_exit_noexc longjmp
>> + * back into the cpu_exec main loop.
>> */
>> tb_lock();
>> tb_check_watchpoint(cpu);
>> @@ -2370,8 +2370,14 @@ static void io_mem_init(void)
>> memory_region_init_io(&io_mem_rom, NULL, &unassigned_mem_ops, NULL,
>> NULL, UINT64_MAX);
>> memory_region_init_io(&io_mem_unassigned, NULL, &unassigned_mem_ops,
>> NULL,
>> NULL, UINT64_MAX);
>> +
>> + /* io_mem_notdirty calls tb_invalidate_phys_page_fast,
>> + * which can be called without the iothread mutex.
>> + */
>> memory_region_init_io(&io_mem_notdirty, NULL, ¬dirty_mem_ops, NULL,
>> NULL, UINT64_MAX);
>> + memory_region_clear_global_locking(&io_mem_notdirty);
>> +
>> memory_region_init_io(&io_mem_watch, NULL, &watch_mem_ops, NULL,
>> NULL, UINT64_MAX);
>> }
>> diff --git a/hw/core/irq.c b/hw/core/irq.c
>> index 49ff2e64fe..b98d1d69f5 100644
>> --- a/hw/core/irq.c
>> +++ b/hw/core/irq.c
>> @@ -22,6 +22,7 @@
>> * THE SOFTWARE.
>> */
>> #include "qemu/osdep.h"
>> +#include "qemu/main-loop.h"
>> #include "qemu-common.h"
>> #include "hw/irq.h"
>> #include "qom/object.h"
>> diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c
>> index 702e281dc8..b3c49b2c61 100644
>> --- a/hw/i386/kvmvapic.c
>> +++ b/hw/i386/kvmvapic.c
>> @@ -451,8 +451,8 @@ static void patch_instruction(VAPICROMState *s, X86CPU
>> *cpu, target_ulong ip)
>> resume_all_vcpus();
>>
>> if (!kvm_enabled()) {
>> - /* tb_lock will be reset when cpu_loop_exit_noexc longjmps
>> - * back into the cpu_exec loop. */
>> + /* Both tb_lock and iothread_mutex will be reset when
>> + * longjmps back into the cpu_exec loop. */
>
> missing cpu_loop_exit_noexc?
Well cpu_exec is the main loop, even if cpu_loop_exit_noexc is what
takes you there. I'll see if I can make it clearer:
/* Both tb_lock and iothread_mutex will be reset when
cpu_loop_exit_noexc longjmps back into the cpu_exec loop */
>
>> tb_lock();
>> tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1);
>> cpu_loop_exit_noexc(cs);
>> diff --git a/hw/intc/arm_gicv3_cpuif.c b/hw/intc/arm_gicv3_cpuif.c
>> index a9ee7fddf9..2624d8d909 100644
>> --- a/hw/intc/arm_gicv3_cpuif.c
>> +++ b/hw/intc/arm_gicv3_cpuif.c
>> @@ -14,6 +14,7 @@
>>
>> #include "qemu/osdep.h"
>> #include "qemu/bitops.h"
>> +#include "qemu/main-loop.h"
>> #include "trace.h"
>> #include "gicv3_internal.h"
>> #include "cpu.h"
>> @@ -733,6 +734,8 @@ void gicv3_cpuif_update(GICv3CPUState *cs)
>> ARMCPU *cpu = ARM_CPU(cs->cpu);
>> CPUARMState *env = &cpu->env;
>>
>> + g_assert(qemu_mutex_iothread_locked());
>> +
>
> tcg_debug_assert()?
Depends if KVM can use this for emulation as well (which I think it can).
>
>> trace_gicv3_cpuif_update(gicv3_redist_affid(cs), cs->hppi.irq,
>> cs->hppi.grp, cs->hppi.prio);
>>
>> diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
>> index 8945869009..59c3faa6c8 100644
>> --- a/hw/ppc/ppc.c
>> +++ b/hw/ppc/ppc.c
>> @@ -62,7 +62,16 @@ void ppc_set_irq(PowerPCCPU *cpu, int n_IRQ, int level)
>> {
>> CPUState *cs = CPU(cpu);
>> CPUPPCState *env = &cpu->env;
>> - unsigned int old_pending = env->pending_interrupts;
>> + unsigned int old_pending;
>> + bool locked = false;
>> +
>> + /* We may already have the BQL if coming from the reset path */
>> + if (!qemu_mutex_iothread_locked()) {
>> + locked = true;
>> + qemu_mutex_lock_iothread();
>> + }
>> +
>> + old_pending = env->pending_interrupts;
>>
>> if (level) {
>> env->pending_interrupts |= 1 << n_IRQ;
>> @@ -80,9 +89,14 @@ void ppc_set_irq(PowerPCCPU *cpu, int n_IRQ, int level)
>> #endif
>> }
>>
>> +
>> LOG_IRQ("%s: %p n_IRQ %d level %d => pending %08" PRIx32
>> "req %08x\n", __func__, env, n_IRQ, level,
>> env->pending_interrupts, CPU(cpu)->interrupt_request);
>> +
>> + if (locked) {
>> + qemu_mutex_unlock_iothread();
>> + }
>> }
>>
>> /* PowerPC 6xx / 7xx internal IRQ controller */
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index a642e663d4..745743d64b 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -1012,6 +1012,9 @@ static void emulate_spapr_hypercall(PowerPCCPU *cpu)
>> {
>> CPUPPCState *env = &cpu->env;
>>
>> + /* The TCG path should also be holding the BQL at this point */
>> + g_assert(qemu_mutex_iothread_locked());
>> +
>
> tcg_debug_assert()?
>
>> if (msr_pr) {
>> hcall_dprintf("Hypercall made with MSR[PR]=1\n");
>> env->gpr[3] = H_PRIVILEGE;
>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>> index 11db2015a4..1a06ae5938 100644
>> --- a/include/qom/cpu.h
>> +++ b/include/qom/cpu.h
>> @@ -325,6 +325,7 @@ struct CPUState {
>> bool unplug;
>> bool crash_occurred;
>> bool exit_request;
>> + /* updates protected by BQL */
>> uint32_t interrupt_request;
>> int singlestep_enabled;
>> int64_t icount_extra;
>> diff --git a/memory.c b/memory.c
>> index 2bfc37f65c..7d7b285e41 100644
>> --- a/memory.c
>> +++ b/memory.c
>> @@ -917,6 +917,8 @@ void memory_region_transaction_commit(void)
>> AddressSpace *as;
>>
>> assert(memory_region_transaction_depth);
>> + assert(qemu_mutex_iothread_locked());
>> +
>> --memory_region_transaction_depth;
>> if (!memory_region_transaction_depth) {
>> if (memory_region_update_pending) {
>> diff --git a/qom/cpu.c b/qom/cpu.c
>> index 7f575879f6..bd77c05cd0 100644
>> --- a/qom/cpu.c
>> +++ b/qom/cpu.c
>> @@ -113,9 +113,19 @@ static void cpu_common_get_memory_mapping(CPUState *cpu,
>> error_setg(errp, "Obtaining memory mappings is unsupported on this
>> CPU.");
>> }
>>
>> +/* Resetting the IRQ comes from across the code base so we take the
>> + * BQL here if we need to. cpu_interrupt assumes it is held.*/
>> void cpu_reset_interrupt(CPUState *cpu, int mask)
>> {
>> + bool need_lock = !qemu_mutex_iothread_locked();
>> +
>> + if (need_lock) {
>> + qemu_mutex_lock_iothread();
>> + }
>> cpu->interrupt_request &= ~mask;
>> + if (need_lock) {
>> + qemu_mutex_unlock_iothread();
>> + }
>> }
>>
>> void cpu_exit(CPUState *cpu)
>> diff --git a/target/arm/helper.c b/target/arm/helper.c
>> index 7111c8cf18..84d789be93 100644
>> --- a/target/arm/helper.c
>> +++ b/target/arm/helper.c
>> @@ -6693,6 +6693,12 @@ void arm_cpu_do_interrupt(CPUState *cs)
>> arm_cpu_do_interrupt_aarch32(cs);
>> }
>>
>> + /* Hooks may change global state so BQL should be held, also the
>> + * BQL needs to be held for any modification of
>> + * cs->interrupt_request.
>> + */
>> + g_assert(qemu_mutex_iothread_locked());
>> +
>> arm_call_el_change_hook(cpu);
>>
>> if (!kvm_enabled()) {
>> diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c
>> index ba796d898e..e1a883c595 100644
>> --- a/target/arm/op_helper.c
>> +++ b/target/arm/op_helper.c
>> @@ -18,6 +18,7 @@
>> */
>> #include "qemu/osdep.h"
>> #include "qemu/log.h"
>> +#include "qemu/main-loop.h"
>> #include "cpu.h"
>> #include "exec/helper-proto.h"
>> #include "internals.h"
>> @@ -487,7 +488,9 @@ void HELPER(cpsr_write_eret)(CPUARMState *env, uint32_t
>> val)
>> */
>> env->regs[15] &= (env->thumb ? ~1 : ~3);
>>
>> + qemu_mutex_lock_iothread();
>> arm_call_el_change_hook(arm_env_get_cpu(env));
>> + qemu_mutex_unlock_iothread();
>> }
>>
>> /* Access to user mode registers from privileged modes. */
>> @@ -735,28 +738,58 @@ void HELPER(set_cp_reg)(CPUARMState *env, void *rip,
>> uint32_t value)
>> {
>> const ARMCPRegInfo *ri = rip;
>>
>> - ri->writefn(env, ri, value);
>> + if (ri->type & ARM_CP_IO) {
>> + qemu_mutex_lock_iothread();
>> + ri->writefn(env, ri, value);
>> + qemu_mutex_unlock_iothread();
>> + } else {
>> + ri->writefn(env, ri, value);
>> + }
>> }
>>
>> uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip)
>> {
>> const ARMCPRegInfo *ri = rip;
>> + uint32_t res;
>>
>> - return ri->readfn(env, ri);
>> + if (ri->type & ARM_CP_IO) {
>> + qemu_mutex_lock_iothread();
>> + res = ri->readfn(env, ri);
>> + qemu_mutex_unlock_iothread();
>> + } else {
>> + res = ri->readfn(env, ri);
>> + }
>> +
>> + return res;
>> }
>>
>> void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value)
>> {
>> const ARMCPRegInfo *ri = rip;
>>
>> - ri->writefn(env, ri, value);
>> + if (ri->type & ARM_CP_IO) {
>> + qemu_mutex_lock_iothread();
>> + ri->writefn(env, ri, value);
>> + qemu_mutex_unlock_iothread();
>> + } else {
>> + ri->writefn(env, ri, value);
>> + }
>> }
>>
>> uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
>> {
>> const ARMCPRegInfo *ri = rip;
>> + uint64_t res;
>> +
>> + if (ri->type & ARM_CP_IO) {
>> + qemu_mutex_lock_iothread();
>> + res = ri->readfn(env, ri);
>> + qemu_mutex_unlock_iothread();
>> + } else {
>> + res = ri->readfn(env, ri);
>> + }
>>
>> - return ri->readfn(env, ri);
>> + return res;
>> }
>>
>> void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm)
>> @@ -989,7 +1022,9 @@ void HELPER(exception_return)(CPUARMState *env)
>> cur_el, new_el, env->pc);
>> }
>>
>> + qemu_mutex_lock_iothread();
>> arm_call_el_change_hook(arm_env_get_cpu(env));
>> + qemu_mutex_unlock_iothread();
>>
>> return;
>>
>> diff --git a/target/i386/smm_helper.c b/target/i386/smm_helper.c
>> index 4dd6a2c544..f051a77c4a 100644
>> --- a/target/i386/smm_helper.c
>> +++ b/target/i386/smm_helper.c
>> @@ -18,6 +18,7 @@
>> */
>>
>> #include "qemu/osdep.h"
>> +#include "qemu/main-loop.h"
>> #include "cpu.h"
>> #include "exec/helper-proto.h"
>> #include "exec/log.h"
>> @@ -42,11 +43,14 @@ void helper_rsm(CPUX86State *env)
>> #define SMM_REVISION_ID 0x00020000
>> #endif
>>
>> +/* Called with iothread lock taken */
>> void cpu_smm_update(X86CPU *cpu)
>> {
>> CPUX86State *env = &cpu->env;
>> bool smm_enabled = (env->hflags & HF_SMM_MASK);
>>
>> + g_assert(qemu_mutex_iothread_locked());
>> +
>> if (cpu->smram) {
>> memory_region_set_enabled(cpu->smram, smm_enabled);
>> }
>> @@ -333,7 +337,10 @@ void helper_rsm(CPUX86State *env)
>> }
>> env->hflags2 &= ~HF2_SMM_INSIDE_NMI_MASK;
>> env->hflags &= ~HF_SMM_MASK;
>> +
>> + qemu_mutex_lock_iothread();
>> cpu_smm_update(cpu);
>> + qemu_mutex_unlock_iothread();
>>
>> qemu_log_mask(CPU_LOG_INT, "SMM: after RSM\n");
>> log_cpu_state_mask(CPU_LOG_INT, CPU(cpu), CPU_DUMP_CCOP);
>> diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c
>> index c9604ea9c7..3cb942e8bb 100644
>> --- a/target/s390x/misc_helper.c
>> +++ b/target/s390x/misc_helper.c
>> @@ -25,6 +25,7 @@
>> #include "exec/helper-proto.h"
>> #include "sysemu/kvm.h"
>> #include "qemu/timer.h"
>> +#include "qemu/main-loop.h"
>> #include "exec/address-spaces.h"
>> #ifdef CONFIG_KVM
>> #include <linux/kvm.h>
>> @@ -109,11 +110,13 @@ void program_interrupt(CPUS390XState *env, uint32_t
>> code, int ilen)
>> /* SCLP service call */
>> uint32_t HELPER(servc)(CPUS390XState *env, uint64_t r1, uint64_t r2)
>> {
>> + qemu_mutex_lock_iothread();
>> int r = sclp_service_call(env, r1, r2);
>> if (r < 0) {
>> program_interrupt(env, -r, 4);
>> - return 0;
>> + r = 0;
>> }
>> + qemu_mutex_unlock_iothread();
>> return r;
>> }
>>
>> diff --git a/translate-all.c b/translate-all.c
>> index 055436a676..41b36f04c6 100644
>> --- a/translate-all.c
>> +++ b/translate-all.c
>> @@ -55,6 +55,7 @@
>> #include "translate-all.h"
>> #include "qemu/bitmap.h"
>> #include "qemu/timer.h"
>> +#include "qemu/main-loop.h"
>> #include "exec/log.h"
>>
>> /* #define DEBUG_TB_INVALIDATE */
>> @@ -1521,7 +1522,7 @@ void tb_invalidate_phys_page_range(tb_page_addr_t
>> start, tb_page_addr_t end,
>> #ifdef CONFIG_SOFTMMU
>> /* len must be <= 8 and start must be a multiple of len.
>> * Called via softmmu_template.h when code areas are written to with
>> - * tb_lock held.
>> + * iothread mutex not held.
>> */
>> void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len)
>> {
>
> Shouldn't this be both tb_lock and iothread mutex?
>
>> @@ -1723,7 +1724,10 @@ void tb_check_watchpoint(CPUState *cpu)
>>
>> #ifndef CONFIG_USER_ONLY
>> /* in deterministic execution mode, instructions doing device I/Os
>> - must be at the end of the TB */
>> + * must be at the end of the TB.
>> + *
>> + * Called by softmmu_template.h, with iothread mutex not held.
>> + */
>> void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
>> {
>> #if defined(TARGET_MIPS) || defined(TARGET_SH4)
>> @@ -1935,6 +1939,7 @@ void dump_opcount_info(FILE *f, fprintf_function
>> cpu_fprintf)
>>
>> void cpu_interrupt(CPUState *cpu, int mask)
>> {
>> + g_assert(qemu_mutex_iothread_locked());
>> cpu->interrupt_request |= mask;
>> cpu->tcg_exit_req = 1;
>> }
>> diff --git a/translate-common.c b/translate-common.c
>> index 5e989cdf70..d504dd0d33 100644
>> --- a/translate-common.c
>> +++ b/translate-common.c
>> @@ -21,6 +21,7 @@
>> #include "qemu-common.h"
>> #include "qom/cpu.h"
>> #include "sysemu/cpus.h"
>> +#include "qemu/main-loop.h"
>>
>> uintptr_t qemu_real_host_page_size;
>> intptr_t qemu_real_host_page_mask;
>> @@ -30,6 +31,7 @@ intptr_t qemu_real_host_page_mask;
>> static void tcg_handle_interrupt(CPUState *cpu, int mask)
>> {
>> int old_mask;
>> + g_assert(qemu_mutex_iothread_locked());
>>
>> old_mask = cpu->interrupt_request;
>> cpu->interrupt_request |= mask;
>> @@ -40,17 +42,16 @@ static void tcg_handle_interrupt(CPUState *cpu, int mask)
>> */
>> if (!qemu_cpu_is_self(cpu)) {
>> qemu_cpu_kick(cpu);
>> - return;
>> - }
>> -
>> - if (use_icount) {
>> - cpu->icount_decr.u16.high = 0xffff;
>> - if (!cpu->can_do_io
>> - && (mask & ~old_mask) != 0) {
>> - cpu_abort(cpu, "Raised interrupt while not in I/O function");
>> - }
>> } else {
>> - cpu->tcg_exit_req = 1;
>> + if (use_icount) {
>> + cpu->icount_decr.u16.high = 0xffff;
>> + if (!cpu->can_do_io
>> + && (mask & ~old_mask) != 0) {
>> + cpu_abort(cpu, "Raised interrupt while not in I/O
>> function");
>> + }
>> + } else {
>> + cpu->tcg_exit_req = 1;
>> + }
>> }
>> }
>
> Reviewed-by: Pranith Kumar <address@hidden>
Thanks.
--
Alex Bennée