From 210f84b0ca7743f3b2a9acfae81df668dbbb6a12 Mon Sep 17 00:00:00 2001 From: Wincy Van Date: Fri, 28 Apr 2017 13:13:58 +0800 Subject: [PATCH] x86: irq: Define a global vector for nested posted interrupts 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 Signed-off-by: Paolo Bonzini --- 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 | 3 ++- arch/x86/kernel/irq.c | 19 +++++++++++++++++++ arch/x86/kernel/irqinit.c | 2 ++ 7 files changed, 29 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index a9a8027a6c0e..d271fb79248f 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -705,6 +705,7 @@ 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 df002992d8fd..07b06955a05d 100644 --- a/arch/x86/include/asm/entry_arch.h +++ b/arch/x86/include/asm/entry_arch.h @@ -25,6 +25,8 @@ BUILD_INTERRUPT3(kvm_posted_intr_ipi, POSTED_INTR_VECTOR, 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 9b76cd331990..ad1ed531febc 100644 --- a/arch/x86/include/asm/hardirq.h +++ b/arch/x86/include/asm/hardirq.h @@ -15,6 +15,7 @@ typedef struct { #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 b90e1053049b..d6dbafbd4207 100644 --- a/arch/x86/include/asm/hw_irq.h +++ b/arch/x86/include/asm/hw_irq.h @@ -30,6 +30,7 @@ extern asmlinkage void apic_timer_interrupt(void); 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 @@ extern void trace_call_function_single_interrupt(void); #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 6ca9fd6234e1..aaf8d28b5d00 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -83,7 +83,6 @@ */ #define X86_PLATFORM_IPI_VECTOR 0xf7 -#define POSTED_INTR_WAKEUP_VECTOR 0xf1 /* * IRQ work vector: */ @@ -98,6 +97,8 @@ /* Vector for KVM to deliver posted interrupt IPI */ #ifdef CONFIG_HAVE_KVM #define POSTED_INTR_VECTOR 0xf2 +#define POSTED_INTR_WAKEUP_VECTOR 0xf1 +#define POSTED_INTR_NESTED_VECTOR 0xf0 #endif /* diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 4aa03c5a14c9..4ed0aba8dbc8 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -155,6 +155,12 @@ int arch_show_interrupts(struct seq_file *p, int prec) seq_printf(p, "%10u ", irq_stats(j)->kvm_posted_intr_ipis); seq_puts(p, " Posted-interrupt notification event\n"); + seq_printf(p, "%*s: ", prec, "NPI"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", + irq_stats(j)->kvm_posted_intr_nested_ipis); + seq_puts(p, " Nested posted-interrupt event\n"); + seq_printf(p, "%*s: ", prec, "PIW"); for_each_online_cpu(j) seq_printf(p, "%10u ", @@ -313,6 +319,19 @@ __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 7468c6987547..c7fd18526c3e 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 */ -- 2.20.1