From: Gleb Natapov <[email protected]> mp_state, unlike other cpu state, can be changed not only from vcpu context it belongs to, but by other vcpus too. That makes its loading from kernel/saving back not safe if mp_state value is changed inside kernel between load and save. For example vcpu 1 loads mp_sate into user-space and the state is RUNNING, vcpu 0 sends INIT/SIPI to vcpu 1 so in-kernel mp_sate becomes SIPI, vcpu 1 save user-space copy into kernel and calls vcpu_run(). SIPI sate is lost.
The patch copies mp_sate into kernel only when it is knows that int-kernel value is outdated. This happens on reset and vmload. Signed-off-by: Gleb Natapov <[email protected]> Signed-off-by: Marcelo Tosatti <[email protected]> diff --git a/hw/apic.c b/hw/apic.c index b8fe529..3910507 100644 --- a/hw/apic.c +++ b/hw/apic.c @@ -512,6 +512,7 @@ void apic_init_reset(CPUState *env) if (kvm_enabled() && kvm_irqchip_in_kernel()) { env->mp_state = env->halted ? KVM_MP_STATE_UNINITIALIZED : KVM_MP_STATE_RUNNABLE; + kvm_load_mpstate(env); } #endif } diff --git a/monitor.c b/monitor.c index 7f0f5a9..dd8f2ca 100644 --- a/monitor.c +++ b/monitor.c @@ -350,6 +350,7 @@ static CPUState *mon_get_cpu(void) mon_set_cpu(0); } cpu_synchronize_state(cur_mon->mon_cpu); + kvm_save_mpstate(cur_mon->mon_cpu); return cur_mon->mon_cpu; } @@ -377,6 +378,7 @@ static void do_info_cpus(Monitor *mon) for(env = first_cpu; env != NULL; env = env->next_cpu) { cpu_synchronize_state(env); + kvm_save_mpstate(env); monitor_printf(mon, "%c CPU #%d:", (env == mon->mon_cpu) ? '*' : ' ', env->cpu_index); diff --git a/qemu-kvm.c b/qemu-kvm.c index b6c36e0..e168db2 100644 --- a/qemu-kvm.c +++ b/qemu-kvm.c @@ -1579,11 +1579,6 @@ static void on_vcpu(CPUState *env, void (*func)(void *data), void *data) void kvm_arch_get_registers(CPUState *env) { kvm_arch_save_regs(env); - kvm_arch_save_mpstate(env); -#ifdef KVM_CAP_MP_STATE - if (kvm_irqchip_in_kernel()) - env->halted = (env->mp_state == KVM_MP_STATE_HALTED); -#endif } static void do_kvm_cpu_synchronize_state(void *_env) @@ -1677,6 +1672,10 @@ static void kvm_do_save_mpstate(void *_env) CPUState *env = _env; kvm_arch_save_mpstate(env); +#ifdef KVM_CAP_MP_STATE + if (kvm_irqchip_in_kernel()) + env->halted = (env->mp_state == KVM_MP_STATE_HALTED); +#endif } void kvm_save_mpstate(CPUState *env) diff --git a/qemu-kvm.h b/qemu-kvm.h index 863911d..6a886b1 100644 --- a/qemu-kvm.h +++ b/qemu-kvm.h @@ -1142,7 +1142,6 @@ void kvm_arch_get_registers(CPUState *env); static inline void kvm_arch_put_registers(CPUState *env) { kvm_load_registers(env); - kvm_load_mpstate(env); } void kvm_cpu_synchronize_state(CPUState *env); diff --git a/target-i386/machine.c b/target-i386/machine.c index e640dad..16d9c57 100644 --- a/target-i386/machine.c +++ b/target-i386/machine.c @@ -324,6 +324,7 @@ static void cpu_pre_save(void *opaque) int i, bit; cpu_synchronize_state(env); + kvm_save_mpstate(env); /* FPU */ env->fpus_vmstate = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11; @@ -385,6 +386,8 @@ static int cpu_post_load(void *opaque, int version_id) } tlb_flush(env, 1); + kvm_load_mpstate(env); + return 0; } -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
