From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: [PATCH v2] xen/events: Support event channel rebind on ARM Date: Mon, 27 Jul 2015 12:35:11 +0100 Message-ID: <1437996911-18985-1-git-send-email-julien.grall__33021.429522387$1437997091$gmane$org@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZJghm-0007P9-T4 for xen-devel@lists.xenproject.org; Mon, 27 Jul 2015 11:36:27 +0000 List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: x86@kernel.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Julien Grall , Ingo Molnar , David Vrabel , "H. Peter Anvin" , Boris Ostrovsky , Thomas Gleixner , linux-arm-kernel@lists.infradead.org List-Id: xen-devel@lists.xenproject.org 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. Signed-off-by: Julien Grall Reviewed-by: David Vrabel Cc: Stefano Stabellini Cc: Catalin Marinas Cc: Will Deacon Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org --- Tested by setting the affinity manually via /proc on dom0 ARM64 Changes in v2: - Use a static inline rather than a macro - Add David's reviewed-by --- arch/arm/include/asm/xen/events.h | 6 ++++++ arch/arm/xen/enlighten.c | 4 ---- arch/arm64/include/asm/xen/events.h | 6 ++++++ arch/x86/include/asm/xen/events.h | 14 ++++++++++++++ drivers/xen/events/events_base.c | 6 +----- include/xen/events.h | 1 - 6 files changed, 27 insertions(+), 10 deletions(-) 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); -- 2.1.4