diff options
Diffstat (limited to 'kvm-all.c')
| -rw-r--r-- | kvm-all.c | 150 |
1 files changed, 139 insertions, 11 deletions
@@ -120,6 +120,7 @@ bool kvm_vm_attributes_allowed; bool kvm_direct_msi_allowed; bool kvm_ioeventfd_any_length_allowed; bool kvm_msi_use_devid; +static bool kvm_immediate_exit; static const KVMCapabilityInfo kvm_required_capabilites[] = { KVM_CAP_INFO(USER_MEMORY), @@ -1619,6 +1620,7 @@ static int kvm_init(MachineState *ms) goto err; } + kvm_immediate_exit = kvm_check_extension(s, KVM_CAP_IMMEDIATE_EXIT); s->nr_slots = kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS); /* If unspecified, use the default value */ @@ -1893,6 +1895,61 @@ void kvm_cpu_synchronize_post_init(CPUState *cpu) run_on_cpu(cpu, do_kvm_cpu_synchronize_post_init, RUN_ON_CPU_NULL); } +#ifdef KVM_HAVE_MCE_INJECTION +static __thread void *pending_sigbus_addr; +static __thread int pending_sigbus_code; +static __thread bool have_sigbus_pending; +#endif + +static void kvm_cpu_kick(CPUState *cpu) +{ + atomic_set(&cpu->kvm_run->immediate_exit, 1); +} + +static void kvm_cpu_kick_self(void) +{ + if (kvm_immediate_exit) { + kvm_cpu_kick(current_cpu); + } else { + qemu_cpu_kick_self(); + } +} + +static void kvm_eat_signals(CPUState *cpu) +{ + struct timespec ts = { 0, 0 }; + siginfo_t siginfo; + sigset_t waitset; + sigset_t chkset; + int r; + + if (kvm_immediate_exit) { + atomic_set(&cpu->kvm_run->immediate_exit, 0); + /* Write kvm_run->immediate_exit before the cpu->exit_request + * write in kvm_cpu_exec. + */ + smp_wmb(); + return; + } + + sigemptyset(&waitset); + sigaddset(&waitset, SIG_IPI); + + do { + r = sigtimedwait(&waitset, &siginfo, &ts); + if (r == -1 && !(errno == EAGAIN || errno == EINTR)) { + perror("sigtimedwait"); + exit(1); + } + + r = sigpending(&chkset); + if (r == -1) { + perror("sigpending"); + exit(1); + } + } while (sigismember(&chkset, SIG_IPI)); +} + int kvm_cpu_exec(CPUState *cpu) { struct kvm_run *run = cpu->kvm_run; @@ -1901,7 +1958,7 @@ int kvm_cpu_exec(CPUState *cpu) DPRINTF("kvm_cpu_exec()\n"); if (kvm_arch_process_async_events(cpu)) { - cpu->exit_request = 0; + atomic_set(&cpu->exit_request, 0); return EXCP_HLT; } @@ -1916,23 +1973,39 @@ int kvm_cpu_exec(CPUState *cpu) } kvm_arch_pre_run(cpu, run); - if (cpu->exit_request) { + if (atomic_read(&cpu->exit_request)) { DPRINTF("interrupt exit requested\n"); /* * KVM requires us to reenter the kernel after IO exits to complete * instruction emulation. This self-signal will ensure that we * leave ASAP again. */ - qemu_cpu_kick_self(); + kvm_cpu_kick_self(); } + /* Read cpu->exit_request before KVM_RUN reads run->immediate_exit. + * Matching barrier in kvm_eat_signals. + */ + smp_rmb(); + run_ret = kvm_vcpu_ioctl(cpu, KVM_RUN, 0); attrs = kvm_arch_post_run(cpu, run); +#ifdef KVM_HAVE_MCE_INJECTION + if (unlikely(have_sigbus_pending)) { + qemu_mutex_lock_iothread(); + kvm_arch_on_sigbus_vcpu(cpu, pending_sigbus_code, + pending_sigbus_addr); + have_sigbus_pending = false; + qemu_mutex_unlock_iothread(); + } +#endif + if (run_ret < 0) { if (run_ret == -EINTR || run_ret == -EAGAIN) { DPRINTF("io window exit\n"); + kvm_eat_signals(cpu); ret = EXCP_INTERRUPT; break; } @@ -2026,7 +2099,7 @@ int kvm_cpu_exec(CPUState *cpu) vm_stop(RUN_STATE_INTERNAL_ERROR); } - cpu->exit_request = 0; + atomic_set(&cpu->exit_request, 0); return ret; } @@ -2372,16 +2445,12 @@ void kvm_remove_all_breakpoints(CPUState *cpu) } #endif /* !KVM_CAP_SET_GUEST_DEBUG */ -int kvm_set_signal_mask(CPUState *cpu, const sigset_t *sigset) +static int kvm_set_signal_mask(CPUState *cpu, const sigset_t *sigset) { KVMState *s = kvm_state; struct kvm_signal_mask *sigmask; int r; - if (!sigset) { - return kvm_vcpu_ioctl(cpu, KVM_SET_SIGNAL_MASK, NULL); - } - sigmask = g_malloc(sizeof(*sigmask) + sizeof(*sigset)); sigmask->len = s->sigmask_len; @@ -2391,14 +2460,73 @@ int kvm_set_signal_mask(CPUState *cpu, const sigset_t *sigset) return r; } + +static void kvm_ipi_signal(int sig) +{ + if (current_cpu) { + assert(kvm_immediate_exit); + kvm_cpu_kick(current_cpu); + } +} + +void kvm_init_cpu_signals(CPUState *cpu) +{ + int r; + sigset_t set; + struct sigaction sigact; + + memset(&sigact, 0, sizeof(sigact)); + sigact.sa_handler = kvm_ipi_signal; + sigaction(SIG_IPI, &sigact, NULL); + + pthread_sigmask(SIG_BLOCK, NULL, &set); +#if defined KVM_HAVE_MCE_INJECTION + sigdelset(&set, SIGBUS); + pthread_sigmask(SIG_SETMASK, &set, NULL); +#endif + sigdelset(&set, SIG_IPI); + if (kvm_immediate_exit) { + r = pthread_sigmask(SIG_SETMASK, &set, NULL); + } else { + r = kvm_set_signal_mask(cpu, &set); + } + if (r) { + fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r)); + exit(1); + } +} + +/* Called asynchronously in VCPU thread. */ int kvm_on_sigbus_vcpu(CPUState *cpu, int code, void *addr) { - return kvm_arch_on_sigbus_vcpu(cpu, code, addr); +#ifdef KVM_HAVE_MCE_INJECTION + if (have_sigbus_pending) { + return 1; + } + have_sigbus_pending = true; + pending_sigbus_addr = addr; + pending_sigbus_code = code; + atomic_set(&cpu->exit_request, 1); + return 0; +#else + return 1; +#endif } +/* Called synchronously (via signalfd) in main thread. */ int kvm_on_sigbus(int code, void *addr) { - return kvm_arch_on_sigbus(code, addr); +#ifdef KVM_HAVE_MCE_INJECTION + /* Action required MCE kills the process if SIGBUS is blocked. Because + * that's what happens in the I/O thread, where we handle MCE via signalfd, + * we can only get action optional here. + */ + assert(code != BUS_MCEERR_AR); + kvm_arch_on_sigbus_vcpu(first_cpu, code, addr); + return 0; +#else + return 1; +#endif } int kvm_create_device(KVMState *s, uint64_t type, bool test) |