RE: [v3 21/26] x86, irq: Define a global vector for VT-d Posted-Interrupts

From: Wu, Feng
Date: Thu Dec 18 2014 - 19:53:38 EST

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In reply to: Zhang, Yang Z: "RE: [v3 21/26] x86, irq: Define a global vector for VT-d Posted-Interrupts"
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> -----Original Message-----
> From: Zhang, Yang Z
> Sent: Thursday, December 18, 2014 10:55 PM
> To: Wu, Feng; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx;
> x86@xxxxxxxxxx; gleb@xxxxxxxxxx; pbonzini@xxxxxxxxxx;
> dwmw2@xxxxxxxxxxxxx; joro@xxxxxxxxxx; alex.williamson@xxxxxxxxxx;
> jiang.liu@xxxxxxxxxxxxxxx
> Cc: eric.auger@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Wu, Feng
> Subject: RE: [v3 21/26] x86, irq: Define a global vector for VT-d
> Posted-Interrupts
>
> Feng Wu wrote on 2014-12-12:
> > Currently, we use a global vector as the Posted-Interrupts
> > Notification Event for all the vCPUs in the system. We need to
> > introduce another global vector for VT-d Posted-Interrtups, which will
> > be used to wakeup the sleep vCPU when an external interrupt from a
> direct-assigned device happens for that vCPU.
> >
>
> Hi Feng,
>
> Since the idea of two global vectors mechanism is from me, please add me to
> the comments.

No problem, Yang, I will add a "suggested-by Yang Zhang <yang.z.zhang@xxxxxxxxx>"
in this patch. Thanks a lot!

Thanks,
Feng

>
> > Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
> > ---
> > 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/entry_64.S | 2 ++
> > arch/x86/kernel/irq.c | 27
> +++++++++++++++++++++++++++
> > arch/x86/kernel/irqinit.c | 2 ++
> > 7 files changed, 37 insertions(+)
> > diff --git a/arch/x86/include/asm/entry_arch.h
> > b/arch/x86/include/asm/entry_arch.h index dc5fa66..27ca0af 100644 ---
> > a/arch/x86/include/asm/entry_arch.h +++
> > b/arch/x86/include/asm/entry_arch.h @@ -23,6 +23,8 @@
> > BUILD_INTERRUPT(x86_platform_ipi, X86_PLATFORM_IPI_VECTOR) #ifdef
> > CONFIG_HAVE_KVM 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)
> > #endif
> >
> > /*
> > diff --git a/arch/x86/include/asm/hardirq.h
> > b/arch/x86/include/asm/hardirq.h index 0f5fb6b..9866065 100644
> > --- a/arch/x86/include/asm/hardirq.h
> > +++ b/arch/x86/include/asm/hardirq.h
> > @@ -14,6 +14,7 @@ typedef struct {
> > #endif #ifdef CONFIG_HAVE_KVM unsigned int kvm_posted_intr_ipis;
> > + unsigned int kvm_posted_intr_wakeup_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 e7ae6eb..38fac9b 100644
> > --- a/arch/x86/include/asm/hw_irq.h
> > +++ b/arch/x86/include/asm/hw_irq.h
> > @@ -29,6 +29,7 @@
> > 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 error_interrupt(void); extern asmlinkage void
> > irq_work_interrupt(void);
> >
> > @@ -92,6 +93,7 @@ extern void
> > trace_call_function_single_interrupt(void);
> > #define trace_irq_move_cleanup_interrupt irq_move_cleanup_interrupt
> > #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
> > #endif /* CONFIG_TRACING */
> >
> > struct irq_domain;
> > diff --git a/arch/x86/include/asm/irq_vectors.h
> > b/arch/x86/include/asm/irq_vectors.h index b26cb12..dca94f2 100644 ---
> > a/arch/x86/include/asm/irq_vectors.h +++
> > b/arch/x86/include/asm/irq_vectors.h @@ -105,6 +105,7 @@
> > /* Vector for KVM to deliver posted interrupt IPI */ #ifdef
> > CONFIG_HAVE_KVM #define POSTED_INTR_VECTOR 0xf2 +#define
> > POSTED_INTR_WAKEUP_VECTOR 0xf1 #endif
> >
> > /*
> > diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
> > index e61c14a..a598447 100644 --- a/arch/x86/kernel/entry_64.S +++
> > b/arch/x86/kernel/entry_64.S @@ -960,6 +960,8 @@ apicinterrupt
> > X86_PLATFORM_IPI_VECTOR \ #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
> > #endif
> >
> > #ifdef CONFIG_X86_MCE_THRESHOLD
> > diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index
> > 922d285..47408c3 100644
> > --- a/arch/x86/kernel/irq.c
> > +++ b/arch/x86/kernel/irq.c
> > @@ -237,6 +237,9 @@ __visible void smp_x86_platform_ipi(struct pt_regs
> > *regs) }
> >
> > #ifdef CONFIG_HAVE_KVM
> > +void (*wakeup_handler_callback)(void) = NULL;
> > +EXPORT_SYMBOL_GPL(wakeup_handler_callback); +
> > /*
> > * Handler for POSTED_INTERRUPT_VECTOR.
> > */
> > @@ -256,6 +259,30 @@ __visible void smp_kvm_posted_intr_ipi(struct
> > pt_regs *regs)
> >
> > set_irq_regs(old_regs);
> > }
> > +
> > +/*
> > + * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
> > + */
> > +__visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs) {
> > + struct pt_regs *old_regs = set_irq_regs(regs);
> > +
> > + ack_APIC_irq();
> > +
> > + irq_enter();
> > +
> > + exit_idle();
> > +
> > + inc_irq_stat(kvm_posted_intr_wakeup_ipis);
> > +
> > + if (wakeup_handler_callback)
> > + wakeup_handler_callback();
> > +
> > + irq_exit();
> > +
> > + set_irq_regs(old_regs);
> > +}
> > +
> > #endif
> >
> > __visible void smp_trace_x86_platform_ipi(struct pt_regs *regs) diff
> > --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index
> > 70e181e..844673c 100644 --- a/arch/x86/kernel/irqinit.c +++
> > b/arch/x86/kernel/irqinit.c @@ -144,6 +144,8 @@ static void __init
> > apic_intr_init(void) #ifdef CONFIG_HAVE_KVM
> > /* IPI for KVM to deliver posted interrupt */
> > 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);
> > #endif
> >
> > /* IPI vectors for APIC spurious and error interrupts */
>
>
> Best regards,
> Yang
>

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Next message: Steven Stewart-Gallus: "When should I not use CLONE_IO?"
Previous message: Laurent Pinchart: "Re: [PATCH] clocksource: sh_tmu: Set cpu_possible_mask to fix SMP broadcast"
In reply to: Zhang, Yang Z: "RE: [v3 21/26] x86, irq: Define a global vector for VT-d Posted-Interrupts"
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