From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:42435) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SuPUg-0004Ex-PZ for qemu-devel@nongnu.org; Thu, 26 Jul 2012 10:56:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SuPUX-000309-FZ for qemu-devel@nongnu.org; Thu, 26 Jul 2012 10:56:50 -0400 Received: from mnementh.archaic.org.uk ([81.2.115.146]:51747) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SuPUX-0002zw-7v for qemu-devel@nongnu.org; Thu, 26 Jul 2012 10:56:41 -0400 From: Peter Maydell Date: Thu, 26 Jul 2012 15:35:11 +0100 Message-Id: <1343313317-27087-2-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1343313317-27087-1-git-send-email-peter.maydell@linaro.org> References: <1343313317-27087-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH v2 1/7] kvm: Decouple 'async interrupt delivery' from 'kernel irqchip' List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Alexander Graf , Marcelo Tosatti , Jan Kiszka , Avi Kivity , patches@linaro.org On x86 userspace delivers interrupts to the kernel asynchronously (and therefore VCPU idle management is done in the kernel) if and only if there is an in-kernel irqchip. On other architectures this isn't necessarily true (they may always send interrupts asynchronously), so define a new kvm_async_interrupts_enabled() function instead of misusing kvm_irqchip_in_kernel(). Signed-off-by: Peter Maydell --- cpus.c | 3 ++- kvm-all.c | 7 ++++++- kvm-stub.c | 1 + kvm.h | 13 +++++++++++++ 4 files changed, 22 insertions(+), 2 deletions(-) diff --git a/cpus.c b/cpus.c index 756e624..8c54dd0 100644 --- a/cpus.c +++ b/cpus.c @@ -69,7 +69,8 @@ static bool cpu_thread_is_idle(CPUArchState *env) if (env->stopped || !runstate_is_running()) { return true; } - if (!env->halted || qemu_cpu_has_work(env) || kvm_irqchip_in_kernel()) { + if (!env->halted || qemu_cpu_has_work(env) || + kvm_async_interrupts_enabled()) { return false; } return true; diff --git a/kvm-all.c b/kvm-all.c index 2148b20..0a38ba1 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -100,6 +100,7 @@ struct KVMState KVMState *kvm_state; bool kvm_kernel_irqchip; +bool kvm_async_interrupts_allowed; static const KVMCapabilityInfo kvm_required_capabilites[] = { KVM_CAP_INFO(USER_MEMORY), @@ -857,7 +858,7 @@ int kvm_irqchip_set_irq(KVMState *s, int irq, int level) struct kvm_irq_level event; int ret; - assert(kvm_irqchip_in_kernel()); + assert(kvm_async_interrupts_enabled()); event.level = level; event.irq = irq; @@ -1201,6 +1202,10 @@ static int kvm_irqchip_create(KVMState *s) s->irqchip_inject_ioctl = KVM_IRQ_LINE_STATUS; } kvm_kernel_irqchip = true; + /* If we have an in-kernel IRQ chip then we must have asynchronous + * interrupt delivery (though the reverse is not necessarily true) + */ + kvm_async_interrupts_allowed = true; kvm_init_irq_routing(s); diff --git a/kvm-stub.c b/kvm-stub.c index d23b11c..a7a03e1 100644 --- a/kvm-stub.c +++ b/kvm-stub.c @@ -19,6 +19,7 @@ KVMState *kvm_state; bool kvm_kernel_irqchip; +bool kvm_async_interrupts_allowed; int kvm_init_vcpu(CPUArchState *env) { diff --git a/kvm.h b/kvm.h index 2617dd5..09818f3 100644 --- a/kvm.h +++ b/kvm.h @@ -24,13 +24,26 @@ extern int kvm_allowed; extern bool kvm_kernel_irqchip; +extern bool kvm_async_interrupts_allowed; #if defined CONFIG_KVM || !defined NEED_CPU_H #define kvm_enabled() (kvm_allowed) #define kvm_irqchip_in_kernel() (kvm_kernel_irqchip) + +/** + * kvm_async_interrupts_enabled: + * + * Returns: true if we can deliver interrupts to KVM + * asynchronously (ie by ioctl from any thread at any time) + * rather than having to do interrupt delivery synchronously + * (where the vcpu must be stopped at a suitable point first). + */ +#define kvm_async_interrupts_enabled() (kvm_async_interrupts_allowed) + #else #define kvm_enabled() (0) #define kvm_irqchip_in_kernel() (false) +#define kvm_async_interrupts_enabled() (false) #endif struct kvm_run; -- 1.7.5.4