diff options
Diffstat (limited to 'cpu-exec.c')
| -rw-r--r-- | cpu-exec.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/cpu-exec.c b/cpu-exec.c index 67381176da..2ffeb6e40d 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -24,6 +24,9 @@ #include "qemu/atomic.h" #include "sysemu/qtest.h" #include "qemu/timer.h" +#include "exec/address-spaces.h" +#include "exec/memory-internal.h" +#include "qemu/rcu.h" /* -icount align implementation. */ @@ -141,6 +144,33 @@ void cpu_resume_from_signal(CPUState *cpu, void *puc) cpu->exception_index = -1; siglongjmp(cpu->jmp_env, 1); } + +void cpu_reload_memory_map(CPUState *cpu) +{ + AddressSpaceDispatch *d; + + if (qemu_in_vcpu_thread()) { + /* Do not let the guest prolong the critical section as much as it + * as it desires. + * + * Currently, this is prevented by the I/O thread's periodinc kicking + * of the VCPU thread (iothread_requesting_mutex, qemu_cpu_kick_thread) + * but this will go away once TCG's execution moves out of the global + * mutex. + * + * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which + * only protects cpu->as->dispatch. Since we reload it below, we can + * split the critical section. + */ + rcu_read_unlock(); + rcu_read_lock(); + } + + /* The CPU and TLB are protected by the iothread lock. */ + d = atomic_rcu_read(&cpu->as->dispatch); + cpu->memory_dispatch = d; + tlb_flush(cpu, 1); +} #endif /* Execute a TB, and fix up the CPU state afterwards if necessary */ @@ -352,6 +382,8 @@ int cpu_exec(CPUArchState *env) * an instruction scheduling constraint on modern architectures. */ smp_mb(); + rcu_read_lock(); + if (unlikely(exit_request)) { cpu->exit_request = 1; } @@ -548,6 +580,7 @@ int cpu_exec(CPUArchState *env) } /* for(;;) */ cc->cpu_exec_exit(cpu); + rcu_read_unlock(); /* fail safe : never use current_cpu outside cpu_exec() */ current_cpu = NULL; |