@@ -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
@@ -384,8 +385,10 @@ 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)) {
@@ -439,7 +442,9 @@ 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 */
@@ -465,9 +470,11 @@ 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;
@@ -522,7 +529,12 @@ 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;
@@ -652,8 +664,12 @@ 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(;;) */
@@ -994,8 +994,6 @@ 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;
@@ -1009,7 +1007,6 @@ 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);
@@ -1052,10 +1049,6 @@ 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);
}
@@ -1216,9 +1209,11 @@ 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
@@ -1393,27 +1388,14 @@ 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());
+ qemu_mutex_lock(&qemu_global_mutex);
iothread_locked = true;
}
void qemu_mutex_unlock_iothread(void)
{
+ g_assert(qemu_mutex_iothread_locked());
iothread_locked = false;
qemu_mutex_unlock(&qemu_global_mutex);
}
@@ -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"
@@ -504,6 +505,7 @@ 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;
@@ -512,7 +514,16 @@ 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;
}
@@ -523,15 +534,23 @@ 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);
}
-
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
@@ -2108,9 +2108,9 @@ 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);
@@ -2345,8 +2345,14 @@ 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);
}
@@ -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"
@@ -450,8 +450,8 @@ 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. */
tb_lock();
tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1);
cpu_loop_exit_noexc(cs);
@@ -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());
+
if (msr_pr) {
hcall_dprintf("Hypercall made with MSR[PR]=1\n");
env->gpr[3] = H_PRIVILEGE;
@@ -323,6 +323,7 @@ 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;
@@ -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) {
@@ -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)
@@ -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);
@@ -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;
}
@@ -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 */
@@ -1541,7 +1542,7 @@ 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)
{
@@ -1743,7 +1744,10 @@ 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)
@@ -1955,6 +1959,7 @@ 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;
}
@@ -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;
+ }
}
}