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[Qemu-devel] Re: [COMMIT 733318e] don't call cpu_sychronize_state from r
From: |
Jan Kiszka |
Subject: |
[Qemu-devel] Re: [COMMIT 733318e] don't call cpu_sychronize_state from reset handlers |
Date: |
Fri, 11 Sep 2009 13:15:49 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
Anthony Liguori wrote:
> From: Glauber Costa <address@hidden>
>
> Doing this will make the vcpu ioctl be issued from the I/O thread, instead
> of cpu thread. The correct behaviour is to call it from within the cpu thread,
> as soon as we are ready to go.
Note that in the good old days, this used to work properly (in qemu-kvm)
as registers write-back was routed through on_vcpu.
>
> Signed-off-by: Glauber Costa <address@hidden>
> Signed-off-by: Anthony Liguori <aliguori-r/address@hidden>
>
> diff --git a/hw/apic.c b/hw/apic.c
> index 2c414c1..9f1d25e 100644
> --- a/hw/apic.c
> +++ b/hw/apic.c
> @@ -938,8 +938,6 @@ static void apic_reset(void *opaque)
> APICState *s = opaque;
> int bsp;
>
> - cpu_synchronize_state(s->cpu_env);
> -
> bsp = cpu_is_bsp(s->cpu_env);
> s->apicbase = 0xfee00000 |
> (bsp ? MSR_IA32_APICBASE_BSP : 0) | MSR_IA32_APICBASE_ENABLE;
> diff --git a/vl.c b/vl.c
> index 8e5d9db..c6c6a6b 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3683,10 +3683,12 @@ static void *kvm_cpu_thread_fn(void *arg)
> while (!qemu_system_ready)
> qemu_cond_timedwait(&qemu_system_cond, &qemu_global_mutex, 100);
>
> + cpu_synchronize_state(env);
> +
> while (1) {
> + qemu_wait_io_event(env);
> if (cpu_can_run(env))
> qemu_cpu_exec(env);
> - qemu_wait_io_event(env);
> }
>
> return NULL;
> @@ -3711,6 +3713,9 @@ static void *tcg_cpu_thread_fn(void *arg)
> while (!qemu_system_ready)
> qemu_cond_timedwait(&qemu_system_cond, &qemu_global_mutex, 100);
>
> + for (env = first_cpu; env != NULL; env = env->next_cpu) {
> + cpu_synchronize_state(env);
> + }
> while (1) {
> tcg_cpu_exec();
> qemu_wait_io_event(cur_cpu);
>
This unfortunately breaks upstream KVM (Linux fails to detect the tiemr
IRQ properly). Is there a fix already in sight? I lost a bit overview of
all on_vcpu refactorings and kvm-register sync "simplifications".
Jan
--
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux
- [Qemu-devel] Re: [COMMIT 733318e] don't call cpu_sychronize_state from reset handlers,
Jan Kiszka <=