From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 1/2] x86: irq: Define a global vector for nested posted interrupts Date: Fri, 28 Apr 2017 12:16:20 +0200 Message-ID: References: <1493356439-7293-1-git-send-email-fanwenyi0529@gmail.com> <1493356439-7293-2-git-send-email-fanwenyi0529@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit To: fanwenyi0529@gmail.com, jmattson@google.com, kvm@vger.kernel.org, Ingo Molnar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35136 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S939018AbdD1KQZ (ORCPT ); Fri, 28 Apr 2017 06:16:25 -0400 In-Reply-To: <1493356439-7293-2-git-send-email-fanwenyi0529@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: Ingo, can you please ack this patch? Thanks, Paolo On 28/04/2017 07:13, fanwenyi0529@gmail.com wrote: > From: Wincy Van > > We are using the same vector for nested/non-nested posted > interrupts delivery, this may cause interrupts latency in > L1 since we can't kick the L2 vcpu out of vmx-nonroot mode. > > This patch introduces a new vector which is only for nested > posted interrupts to solve the problems above. > > Signed-off-by: Wincy Van > --- > arch/x86/entry/entry_64.S | 1 + > arch/x86/include/asm/entry_arch.h | 2 ++ > arch/x86/include/asm/hardirq.h | 1 + > arch/x86/include/asm/hw_irq.h | 2 ++ > arch/x86/include/asm/irq_vectors.h | 1 + > arch/x86/kernel/irq.c | 13 +++++++++++++ > arch/x86/kernel/irqinit.c | 2 ++ > 7 files changed, 22 insertions(+) > > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S > index 044d18e..c01e62c 100644 > --- a/arch/x86/entry/entry_64.S > +++ b/arch/x86/entry/entry_64.S > @@ -710,6 +710,7 @@ apicinterrupt X86_PLATFORM_IPI_VECTOR x86_platform_ipi smp_x86_platform_ipi > #ifdef CONFIG_HAVE_KVM > apicinterrupt3 POSTED_INTR_VECTOR kvm_posted_intr_ipi smp_kvm_posted_intr_ipi > apicinterrupt3 POSTED_INTR_WAKEUP_VECTOR kvm_posted_intr_wakeup_ipi smp_kvm_posted_intr_wakeup_ipi > +apicinterrupt3 POSTED_INTR_NESTED_VECTOR kvm_posted_intr_nested_ipi smp_kvm_posted_intr_nested_ipi > #endif > > #ifdef CONFIG_X86_MCE_THRESHOLD > diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h > index df00299..07b0695 100644 > --- a/arch/x86/include/asm/entry_arch.h > +++ b/arch/x86/include/asm/entry_arch.h > @@ -25,6 +25,8 @@ > smp_kvm_posted_intr_ipi) > BUILD_INTERRUPT3(kvm_posted_intr_wakeup_ipi, POSTED_INTR_WAKEUP_VECTOR, > smp_kvm_posted_intr_wakeup_ipi) > +BUILD_INTERRUPT3(kvm_posted_intr_nested_ipi, POSTED_INTR_NESTED_VECTOR, > + smp_kvm_posted_intr_nested_ipi) > #endif > > /* > diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h > index 59405a2..3a81b21 100644 > --- a/arch/x86/include/asm/hardirq.h > +++ b/arch/x86/include/asm/hardirq.h > @@ -15,6 +15,7 @@ > #ifdef CONFIG_HAVE_KVM > unsigned int kvm_posted_intr_ipis; > unsigned int kvm_posted_intr_wakeup_ipis; > + unsigned int kvm_posted_intr_nested_ipis; > #endif > unsigned int x86_platform_ipis; /* arch dependent */ > unsigned int apic_perf_irqs; > diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h > index b90e105..d6dbafb 100644 > --- a/arch/x86/include/asm/hw_irq.h > +++ b/arch/x86/include/asm/hw_irq.h > @@ -30,6 +30,7 @@ > extern asmlinkage void x86_platform_ipi(void); > extern asmlinkage void kvm_posted_intr_ipi(void); > extern asmlinkage void kvm_posted_intr_wakeup_ipi(void); > +extern asmlinkage void kvm_posted_intr_nested_ipi(void); > extern asmlinkage void error_interrupt(void); > extern asmlinkage void irq_work_interrupt(void); > > @@ -62,6 +63,7 @@ > #define trace_reboot_interrupt reboot_interrupt > #define trace_kvm_posted_intr_ipi kvm_posted_intr_ipi > #define trace_kvm_posted_intr_wakeup_ipi kvm_posted_intr_wakeup_ipi > +#define trace_kvm_posted_intr_nested_ipi kvm_posted_intr_nested_ipi > #endif /* CONFIG_TRACING */ > > #ifdef CONFIG_X86_LOCAL_APIC > diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h > index 6ca9fd6..30f2bc5 100644 > --- a/arch/x86/include/asm/irq_vectors.h > +++ b/arch/x86/include/asm/irq_vectors.h > @@ -98,6 +98,7 @@ > /* Vector for KVM to deliver posted interrupt IPI */ > #ifdef CONFIG_HAVE_KVM > #define POSTED_INTR_VECTOR 0xf2 > +#define POSTED_INTR_NESTED_VECTOR 0xf0 > #endif > > /* > diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c > index 4d8183b..9fed1e1 100644 > --- a/arch/x86/kernel/irq.c > +++ b/arch/x86/kernel/irq.c > @@ -313,6 +313,19 @@ __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs) > exiting_irq(); > set_irq_regs(old_regs); > } > + > +/* > + * Handler for POSTED_INTERRUPT_NESTED_VECTOR. > + */ > +__visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs) > +{ > + struct pt_regs *old_regs = set_irq_regs(regs); > + > + entering_ack_irq(); > + inc_irq_stat(kvm_posted_intr_nested_ipis); > + exiting_irq(); > + set_irq_regs(old_regs); > +} > #endif > > __visible void __irq_entry smp_trace_x86_platform_ipi(struct pt_regs *regs) > diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c > index 1423ab1..4c86c92 100644 > --- a/arch/x86/kernel/irqinit.c > +++ b/arch/x86/kernel/irqinit.c > @@ -150,6 +150,8 @@ static void __init apic_intr_init(void) > alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi); > /* IPI for KVM to deliver interrupt to wake up tasks */ > alloc_intr_gate(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi); > + /* IPI for KVM to deliver nested posted interrupt */ > + alloc_intr_gate(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi); > #endif > > /* IPI vectors for APIC spurious and error interrupts */ >