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

2015-02-23 Thread Marcelo Tosatti 
On Fri, Dec 12, 2014 at 11:14:55PM +0800, Feng Wu wrote:
> 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.
> 
> Signed-off-by: Feng Wu 

Why an additional vector is necessary?

Can't you simply wakeup the vcpu from kvm_posted_intr_ipi, the posted
interrupt vector handler ?

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

2015-02-01 Thread Wu, Feng 


> -Original Message-
> From: H. Peter Anvin [mailto:h...@zytor.com]
> Sent: Saturday, January 31, 2015 2:19 AM
> To: Wu, Feng; t...@linutronix.de; mi...@redhat.com; x...@kernel.org;
> g...@kernel.org; pbonz...@redhat.com; dw...@infradead.org;
> j...@8bytes.org; alex.william...@redhat.com; jiang@linux.intel.com
> Cc: eric.au...@linaro.org; linux-ker...@vger.kernel.org;
> io...@lists.linux-foundation.org; kvm@vger.kernel.org
> Subject: Re: [v3 21/26] x86, irq: Define a global vector for VT-d
> Posted-Interrupts
> 
> On 12/12/2014 07:14 AM, Feng Wu wrote:
> > 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.
> >
> > Signed-off-by: Feng Wu 
> >
> 
> >  #ifdef CONFIG_HAVE_KVM
> > +void (*wakeup_handler_callback)(void) = NULL;
> > +EXPORT_SYMBOL_GPL(wakeup_handler_callback);
> > +
> 
> Stylistic nitpick: we generally don't explicitly initialize
> global/static pointer variables to NULL (that happens automatically anyway.)
> 
> Other than that,
> 
> Acked-by: H. Peter Anvin 

Thanks a lot for your review, Peter!

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

2015-01-30 Thread H. Peter Anvin 
On 12/12/2014 07:14 AM, Feng Wu wrote:
> 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.
> 
> Signed-off-by: Feng Wu 
>  

>  #ifdef CONFIG_HAVE_KVM
> +void (*wakeup_handler_callback)(void) = NULL;
> +EXPORT_SYMBOL_GPL(wakeup_handler_callback);
> +

Stylistic nitpick: we generally don't explicitly initialize
global/static pointer variables to NULL (that happens automatically anyway.)

Other than that,

Acked-by: H. Peter Anvin 

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

2014-12-18 Thread Wu, Feng 


> -Original Message-
> From: Zhang, Yang Z
> Sent: Thursday, December 18, 2014 10:55 PM
> To: Wu, Feng; t...@linutronix.de; mi...@redhat.com; h...@zytor.com;
> x...@kernel.org; g...@kernel.org; pbonz...@redhat.com;
> dw...@infradead.org; j...@8bytes.org; alex.william...@redhat.com;
> jiang@linux.intel.com
> Cc: eric.au...@linaro.org; linux-ker...@vger.kernel.org;
> io...@lists.linux-foundation.org; kvm@vger.kernel.org; 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 
"
in this patch. Thanks a lot!

Thanks,
Feng

> 
> > Signed-off-by: Feng Wu 
> > ---
> >  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; #endifunsigned 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

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

2014-12-18 Thread Zhang, Yang Z 
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.

> Signed-off-by: Feng Wu 
> ---
>  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_KVMunsigned int kvm_posted_intr_ipis;
>  +unsigned int kvm_posted_intr_wakeup_ipis; #endifunsigned 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_VECTOR0xf1 #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

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

2014-12-12 Thread Feng Wu 
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.

Signed-off-by: Feng Wu 
---
 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);