diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/hardirq.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/idtentry.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/irq_vectors.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/idt.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/irq.c | 33 |
5 files changed, 47 insertions, 1 deletions
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h index 275e7fd20310..279afc01f1ac 100644 --- a/arch/x86/include/asm/hardirq.h +++ b/arch/x86/include/asm/hardirq.h @@ -20,6 +20,9 @@ typedef struct { unsigned int kvm_posted_intr_wakeup_ipis; unsigned int kvm_posted_intr_nested_ipis; #endif +#ifdef CONFIG_X86_USER_INTERRUPTS + unsigned int uintr_spurious_count; +#endif unsigned int x86_platform_ipis; /* arch dependent */ unsigned int apic_perf_irqs; unsigned int apic_irq_work_irqs; diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h index 1345088e9902..5929a6f9eeee 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -671,6 +671,10 @@ DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_WAKEUP_VECTOR, sysvec_kvm_posted_intr_wakeup DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR, sysvec_kvm_posted_intr_nested_ipi); #endif +#ifdef CONFIG_X86_USER_INTERRUPTS +DECLARE_IDTENTRY_SYSVEC(UINTR_NOTIFICATION_VECTOR, sysvec_uintr_spurious_interrupt); +#endif + #if IS_ENABLED(CONFIG_HYPERV) DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_hyperv_callback); DECLARE_IDTENTRY_SYSVEC(HYPERV_REENLIGHTENMENT_VECTOR, sysvec_hyperv_reenlightenment); diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index 43dcb9284208..d26faa504931 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -104,7 +104,10 @@ #define HYPERV_STIMER0_VECTOR 0xed #endif -#define LOCAL_TIMER_VECTOR 0xec +/* Vector for User interrupt notifications */ +#define UINTR_NOTIFICATION_VECTOR 0xec + +#define LOCAL_TIMER_VECTOR 0xeb #define NR_VECTORS 256 diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index df0fa695bb09..d8c45e0728f0 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -147,6 +147,9 @@ static const __initconst struct idt_data apic_idts[] = { INTG(POSTED_INTR_WAKEUP_VECTOR, asm_sysvec_kvm_posted_intr_wakeup_ipi), INTG(POSTED_INTR_NESTED_VECTOR, asm_sysvec_kvm_posted_intr_nested_ipi), # endif +#ifdef CONFIG_X86_USER_INTERRUPTS + INTG(UINTR_NOTIFICATION_VECTOR, asm_sysvec_uintr_spurious_interrupt), +#endif # ifdef CONFIG_IRQ_WORK INTG(IRQ_WORK_VECTOR, asm_sysvec_irq_work), # endif diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index e28f6a5d14f1..e3c35668c7c5 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -182,6 +182,12 @@ int arch_show_interrupts(struct seq_file *p, int prec) irq_stats(j)->kvm_posted_intr_wakeup_ipis); seq_puts(p, " Posted-interrupt wakeup event\n"); #endif +#ifdef CONFIG_X86_USER_INTERRUPTS + seq_printf(p, "%*s: ", prec, "UIS"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->uintr_spurious_count); + seq_puts(p, " User-interrupt spurious event\n"); +#endif return 0; } @@ -325,6 +331,33 @@ DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_nested_ipi) } #endif +#ifdef CONFIG_X86_USER_INTERRUPTS +/* + * Handler for UINTR_NOTIFICATION_VECTOR. + * + * The notification vector is used by the cpu to detect a User Interrupt. In + * the typical usage, the cpu would handle this interrupt and clear the local + * apic. + * + * However, it is possible that the kernel might receive this vector. This can + * happen if the receiver thread was running when the interrupt was sent but it + * got scheduled out before the interrupt was delivered. The kernel doesn't + * need to do anything other than clearing the local APIC. A pending user + * interrupt is always saved in the receiver's UPID which can be referenced + * when the receiver gets scheduled back. + * + * If the kernel receives a storm of these, it could mean an issue with the + * kernel's saving and restoring of the User Interrupt MSR state; Specifically, + * the notification vector bits in the IA32_UINTR_MISC_MSR. + */ +DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_uintr_spurious_interrupt) +{ + /* TODO: Add entry-exit tracepoints */ + ack_APIC_irq(); + inc_irq_stat(uintr_spurious_count); +} +#endif + #ifdef CONFIG_HOTPLUG_CPU /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */ |