| Message ID | 1437996911-18985-1-git-send-email-julien.grall@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 27/07/15 12:35, Julien Grall wrote: > Currently, the event channel rebind code is gated with the presence of > the vector callback. > > The virtual interrupt controller on ARM has the concept of per-CPU > interrupt (PPI) which allow us to support per-VCPU event channel. > Therefore there is no need of vector callback for ARM. > > Xen is already using a free PPI to notify the guest VCPU of an event. > Furthermore, the xen code initialization in Linux (see > arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ. > > Introduce new helper xen_support_evtchn_rebind to allow architecture > decide whether rebind an event is support or not. It will always return > 1 on ARM and keep the same behavior on x86. > > This is also allow us to drop the usage of xen_have_vector_callback > entirely in the ARM code. This did not apply cleanly. Please always base patches on Linus's master branch. This also breaks the x86 build. /local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h: In function ‘xen_support_evtchn_rebind’: /local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h:29:85: error: ‘xen_have_vector_callback’ undeclared (first use in this function) return (!xen_hvm_domain() || xen_have_vector_callback); > --- a/arch/arm/include/asm/xen/events.h > +++ b/arch/arm/include/asm/xen/events.h > @@ -20,4 +20,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) > atomic64_t, \ > counter), (val)) > > +/* Rebind event channel is supported by default */ > +static inline bool xen_support_evtchn_rebind(void) > +{ > + return 1; This should be true (similarly for arm64). David
On 27/07/15 13:35, David Vrabel wrote: > On 27/07/15 12:35, Julien Grall wrote: >> Currently, the event channel rebind code is gated with the presence of >> the vector callback. >> >> The virtual interrupt controller on ARM has the concept of per-CPU >> interrupt (PPI) which allow us to support per-VCPU event channel. >> Therefore there is no need of vector callback for ARM. >> >> Xen is already using a free PPI to notify the guest VCPU of an event. >> Furthermore, the xen code initialization in Linux (see >> arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ. >> >> Introduce new helper xen_support_evtchn_rebind to allow architecture >> decide whether rebind an event is support or not. It will always return >> 1 on ARM and keep the same behavior on x86. >> >> This is also allow us to drop the usage of xen_have_vector_callback >> entirely in the ARM code. > > This did not apply cleanly. Please always base patches on Linus's > master branch. My patch is based on Linus's master branch. Although, it has a pre-requisite of [1] which I sent a few seconds before it. Though it's only for applying because the 2 patches are not related. I should have mentioned it in the mail, sorry. > This also breaks the x86 build. I forgot to test this new version when I turned the macro into a static inline. > /local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h: In > function ‘xen_support_evtchn_rebind’: > /local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h:29:85: > error: ‘xen_have_vector_callback’ undeclared (first use in this function) > return (!xen_hvm_domain() || xen_have_vector_callback); > >> --- a/arch/arm/include/asm/xen/events.h >> +++ b/arch/arm/include/asm/xen/events.h >> @@ -20,4 +20,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) >> atomic64_t, \ >> counter), (val)) >> >> +/* Rebind event channel is supported by default */ >> +static inline bool xen_support_evtchn_rebind(void) >> +{ >> + return 1; > > This should be true (similarly for arm64). Will resend a new version, and remove the dependency on [1]. Regards, [1] http://permalink.gmane.org/gmane.linux.kernel/2004690
diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h index 8b1f37b..2123aaa 100644 --- a/arch/arm/include/asm/xen/events.h +++ b/arch/arm/include/asm/xen/events.h @@ -20,4 +20,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) atomic64_t, \ counter), (val)) +/* Rebind event channel is supported by default */ +static inline bool xen_support_evtchn_rebind(void) +{ + return 1; +} + #endif /* _ASM_ARM_XEN_EVENTS_H */ diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 9055c92..c50c8d3 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -45,10 +45,6 @@ static struct vcpu_info __percpu *xen_vcpu_info; unsigned long xen_released_pages; struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; -/* TODO: to be removed */ -__read_mostly int xen_have_vector_callback; -EXPORT_SYMBOL_GPL(xen_have_vector_callback); - static __read_mostly unsigned int xen_events_irq; static __initdata struct device_node *xen_node; diff --git a/arch/arm64/include/asm/xen/events.h b/arch/arm64/include/asm/xen/events.h index 8655321..ed4aa90 100644 --- a/arch/arm64/include/asm/xen/events.h +++ b/arch/arm64/include/asm/xen/events.h @@ -18,4 +18,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) #define xchg_xen_ulong(ptr, val) xchg((ptr), (val)) +/* Rebind event channel is supported by default */ +static inline bool xen_support_evtchn_rebind(void) +{ + return 1; +} + #endif /* _ASM_ARM64_XEN_EVENTS_H */ diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h index 608a79d..37bc720 100644 --- a/arch/x86/include/asm/xen/events.h +++ b/arch/x86/include/asm/xen/events.h @@ -20,4 +20,18 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) /* No need for a barrier -- XCHG is a barrier on x86. */ #define xchg_xen_ulong(ptr, val) xchg((ptr), (val)) +/* + * Events delivered via platform PCI interrupts are always + * routed to vcpu 0 and hence cannot be rebound. + */ +static inline bool xen_support_evtchn_rebind(void) +{ + return (!xen_hvm_domain() || xen_have_vector_callback); +} + +#define xen_support_evtchn_rebind() \ + (!xen_hvm_domain() || xen_have_vector_callback) + +extern int xen_have_vector_callback; + #endif /* _ASM_X86_XEN_EVENTS_H */ diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 96093ae..ed620e5 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1301,11 +1301,7 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu) if (!VALID_EVTCHN(evtchn)) return -1; - /* - * Events delivered via platform PCI interrupts are always - * routed to vcpu 0 and hence cannot be rebound. - */ - if (xen_hvm_domain() && !xen_have_vector_callback) + if (!xen_support_evtchn_rebind()) return -1; /* Send future instances of this interrupt to other vcpu. */ diff --git a/include/xen/events.h b/include/xen/events.h index 7d95fdf..88da2ab 100644 --- a/include/xen/events.h +++ b/include/xen/events.h @@ -92,7 +92,6 @@ void xen_hvm_callback_vector(void); #ifdef CONFIG_TRACING #define trace_xen_hvm_callback_vector xen_hvm_callback_vector #endif -extern int xen_have_vector_callback; int xen_set_callback_via(uint64_t via); void xen_evtchn_do_upcall(struct pt_regs *regs); void xen_hvm_evtchn_do_upcall(void);