From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from db8outboundpool.messaging.microsoft.com (mail-db8lp0188.outbound.messaging.microsoft.com [213.199.154.188]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Microsoft Secure Server Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 2715C2C00E3 for ; Sat, 4 May 2013 04:05:01 +1000 (EST) Date: Fri, 3 May 2013 13:04:47 -0500 From: Scott Wood Subject: Re: [PATCH] KVM: PPC: Book3E 64: Fix IRQs warnings and hangs To: Mihai Caraman In-Reply-To: <1367597470-22214-1-git-send-email-mihai.caraman@freescale.com> (from mihai.caraman@freescale.com on Fri May 3 11:11:10 2013) Message-ID: <1367604287.19391.2@snotra> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; delsp=Yes; format=Flowed Cc: Mihai Caraman , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 05/03/2013 11:11:10 AM, Mihai Caraman wrote: > A change in the generic code highlighted that we were running with =20 > IRQs > (soft) enabled on Book3E 64-bit when trying to restart interrupts from > handle_exit(). This is a lesson to configure lockdep often :) >=20 > There is no reason to exit guest with soft_enabled =3D=3D 1, a =20 > local_irq_enable() > call will do this for us so get rid of kvmppc_layz_ee() calls. With =20 > this fix > we eliminate irqs_disabled() warnings and some guest and host hangs =20 > revealed > under stress tests, but guests still exhibit some unresponsiveness. >=20 > The unresponsiveness has to do with the fact that =20 > arch_local_irq_restore() > does not guarantees to hard enable interrupts. Could you elaborate? If the saved IRQ state was "enabled", why =20 wouldn't arch_local_irq_restore() hard-enable IRQs? The last thing it =20 does is __hard_irq_enable(). Where is the arch_local_irq_restore() instance you're talking about? > 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 =20 > interrupts > hard enabled. Not sure what you mean by "lets the interrupts hard enabled"... Do you =20 mean the EE bit in regs->msr, as opposed to the EE bit in the current =20 MSR? > Signed-off-by: Mihai Caraman > --- > arch/powerpc/kvm/booke.c | 9 +++------ > 1 files changed, 3 insertions(+), 6 deletions(-) >=20 > 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, =20 > struct kvm_vcpu *vcpu) > ret =3D s; > goto out; > } > - kvmppc_lazy_ee_enable(); >=20 > kvm_guest_enter(); >=20 > @@ -789,16 +788,16 @@ static void kvmppc_restart_interrupt(struct =20 > kvm_vcpu *vcpu, > switch (exit_nr) { > case BOOKE_INTERRUPT_EXTERNAL: > kvmppc_fill_pt_regs(®s); > - do_IRQ(®s); > + local_paca->irq_happened |=3D PACA_IRQ_EE; > break; > case BOOKE_INTERRUPT_DECREMENTER: > kvmppc_fill_pt_regs(®s); > - timer_interrupt(®s); > + local_paca->irq_happened |=3D 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 |=3D PACA_IRQ_DBELL; > break; > #endif Aren't you breaking 32-bit here? -Scott=