Re: [PATCH 15/21] qemu-kvm: Clean up mpstate synchronization

Jan Kiszka
2010-02-02T12:32:30Z

Gleb Natapov wrote:
> On Tue, Feb 02, 2010 at 09:19:01AM +0100, Jan Kiszka wrote:
>> Push mpstate reading/writing into kvm_arch_load/save_regs and, on x86,
>> properly synchronize with halted in the accessor functions.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>> hw/apic.c | 7 ----
>> qemu-kvm-ia64.c | 4 ++-
>> qemu-kvm-x86.c | 88 +++++++++++++++++++++++++++---------------------
>> qemu-kvm.c | 30 -----------------
>> qemu-kvm.h | 15 --------
>> target-i386/machine.c | 6 ---
>> target-ia64/machine.c | 3 ++
>> 7 files changed, 55 insertions(+), 98 deletions(-)
>>
>> diff --git a/hw/apic.c b/hw/apic.c
>> index 3e03e10..092c61e 100644
>> --- a/hw/apic.c
>> +++ b/hw/apic.c
>> @@ -507,13 +507,6 @@ void apic_init_reset(CPUState *env)
>> s->wait_for_sipi = 1;
>>
>> env->halted = !(s->apicbase & MSR_IA32_APICBASE_BSP);
>> -#ifdef KVM_CAP_MP_STATE
>> - 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
>> }
>>
>> static void apic_startup(APICState *s, int vector_num)
>> diff --git a/qemu-kvm-ia64.c b/qemu-kvm-ia64.c
>> index fc8110e..39bcbeb 100644
>> --- a/qemu-kvm-ia64.c
>> +++ b/qemu-kvm-ia64.c
>> @@ -124,7 +124,9 @@ void kvm_arch_cpu_reset(CPUState *env)
>> {
>> if (kvm_irqchip_in_kernel(kvm_context)) {
>> #ifdef KVM_CAP_MP_STATE
>> - kvm_reset_mpstate(env->kvm_cpu_state.vcpu_ctx);
>> + struct kvm_mp_state mp_state = {.mp_state = KVM_MP_STATE_UNINITIALIZED
>> + };
>> + kvm_set_mpstate(env, &mp_state);
>> #endif
>> } else {
>> env->interrupt_request &= ~CPU_INTERRUPT_HARD;
>> diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
>> index 63cd095..6b5895f 100644
>> --- a/qemu-kvm-x86.c
>> +++ b/qemu-kvm-x86.c
>> @@ -754,6 +754,48 @@ static int get_msr_entry(struct kvm_msr_entry *entry, CPUState *env)
>> return 0;
>> }
>>
>> +static void kvm_arch_save_mpstate(CPUState *env)
>> +{
>> +#ifdef KVM_CAP_MP_STATE
>> + int r;
>> + struct kvm_mp_state mp_state;
>> +
>> + r = kvm_get_mpstate(env, &mp_state);
>> + if (r < 0) {
>> + env->mp_state = -1;
>> + } else {
>> + env->mp_state = mp_state.mp_state;
>> + if (kvm_irqchip_in_kernel()) {
>> + env->halted = (env->mp_state == KVM_MP_STATE_HALTED);
>> + }
>> + }
>> +#else
>> + env->mp_state = -1;
>> +#endif
>> +}
>> +
>> +static void kvm_arch_load_mpstate(CPUState *env)
>> +{
>> +#ifdef KVM_CAP_MP_STATE
>> + struct kvm_mp_state mp_state;
>> +
>> + /*
>> + * -1 indicates that the host did not support GET_MP_STATE ioctl,
>> + * so don't touch it.
>> + */
>> + if (env->mp_state != -1) {
>> + if (kvm_irqchip_in_kernel()) {
>> + env->mp_state = env->halted ? KVM_MP_STATE_UNINITIALIZED :
>> + KVM_MP_STATE_RUNNABLE;
> When irqchip is in kernel env->halted doesn't contain any relevant
> information, so this is incorrect. Actually env->halted is updated only
> to show correct cpu state during "info cpus".

OK, copied from apic_init_reset, see above. So that hunk was probably at
least useless, and now it's harmfull. Will drop this and only sync from
mp_state -> halted.

Thanks,
Jan

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