| Message ID | 1437845664-32098-1-git-send-email-julien.grall@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 25 Jul 2015, Julien Grall wrote: > +/* > + * Events delivered via platform PCI interrupts are always > + * routed to vcpu 0 and hence cannot be rebound. > + */ > +#define xen_support_evtchn_rebind() \ > + (!xen_hvm_domain() || xen_have_vector_callback) Make this an inline please. Thanks, tglx
On 25/07/15 18:34, 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 macro 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. Reviewed-by: David Vrabel <david.vrabel@citrix.com> Provided you make xen_support_evtchn_rebind() an inline function. David
diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h index 8b1f37b..72d467f 100644 --- a/arch/arm/include/asm/xen/events.h +++ b/arch/arm/include/asm/xen/events.h @@ -20,4 +20,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) atomic64_t, \ counter), (val)) +/* Rebind event channel is supported by default */ +#define xen_support_evtchn_rebind() (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..259eef0 100644 --- a/arch/arm64/include/asm/xen/events.h +++ b/arch/arm64/include/asm/xen/events.h @@ -18,4 +18,7 @@ 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 */ +#define xen_support_evtchn_rebind() (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..e8ed478 100644 --- a/arch/x86/include/asm/xen/events.h +++ b/arch/x86/include/asm/xen/events.h @@ -20,4 +20,13 @@ 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. + */ +#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);
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 macro 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. Signed-off-by: Julien Grall <julien.grall@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org --- Tested by setting the affinity manually via /proc on dom0 ARM64 --- arch/arm/include/asm/xen/events.h | 3 +++ arch/arm/xen/enlighten.c | 4 ---- arch/arm64/include/asm/xen/events.h | 3 +++ arch/x86/include/asm/xen/events.h | 9 +++++++++ drivers/xen/events/events_base.c | 6 +----- include/xen/events.h | 1 - 6 files changed, 16 insertions(+), 10 deletions(-)