On 03.05.2013, at 18:11, Mihai Caraman wrote:
> A change in the generic code highlighted that we were running with IRQs
> (soft) enabled on Book3E 64-bit when trying to restart interrupts from
> handle_exit(). This is a lesson to configure lockdep often :)
>
> There is no reason to exit guest with soft_enabled == 1, a local_irq_enable()
> call will do this for us so get rid of kvmppc_layz_ee() calls. With this fix
> we eliminate irqs_disabled() warnings and some guest and host hangs revealed
> under stress tests, but guests still exhibit some unresponsiveness.
>
> The unresponsiveness has to do with the fact that arch_local_irq_restore()
> does not guarantees to hard enable interrupts. To do so replace exception
> function calls like timer_interrupt() with irq_happened flags. The
> local_irq_enable() call takes care of replaying them and lets the interrupts
> hard enabled.
>
> Signed-off-by: Mihai Caraman <mihai.caraman@xxxxxxxxxxxxx>
Ben, could you please review?
Alex
> ---
> arch/powerpc/kvm/booke.c | 9 +++------
> 1 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index 1020119..82f155e 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -673,7 +673,6 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
> ret = s;
> goto out;
> }
> - kvmppc_lazy_ee_enable();
>
> kvm_guest_enter();
>
> @@ -789,16 +788,16 @@ static void kvmppc_restart_interrupt(struct kvm_vcpu *vcpu,
> switch (exit_nr) {
> case BOOKE_INTERRUPT_EXTERNAL:
> kvmppc_fill_pt_regs(®s);
> - do_IRQ(®s);
> + local_paca->irq_happened |= PACA_IRQ_EE;
> break;
> case BOOKE_INTERRUPT_DECREMENTER:
> kvmppc_fill_pt_regs(®s);
> - timer_interrupt(®s);
> + local_paca->irq_happened |= PACA_IRQ_DEC;
> break;
> #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_BOOK3E_64)
> case BOOKE_INTERRUPT_DOORBELL:
> kvmppc_fill_pt_regs(®s);
> - doorbell_exception(®s);
> + local_paca->irq_happened |= PACA_IRQ_DBELL;
> break;
> #endif
> case BOOKE_INTERRUPT_MACHINE_CHECK:
> @@ -1148,8 +1147,6 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
> if (s <= 0) {
> local_irq_enable();
> r = (s << 2) | RESUME_HOST | (r & RESUME_FLAG_NV);
> - } else {
> - kvmppc_lazy_ee_enable();
> }
> }
>
> --
> 1.7.4.1
>
>
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