From patchwork Fri Mar 5 14:42:21 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Whitcroft X-Patchwork-Id: 47008 X-Patchwork-Delegate: apw@canonical.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 97D79B7CEF for ; Sat, 6 Mar 2010 01:42:34 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.69) (envelope-from ) id 1NnYjT-0006TJ-Oh; Fri, 05 Mar 2010 14:42:27 +0000 Received: from adelie.canonical.com ([91.189.90.139]) by chlorine.canonical.com with esmtp (Exim 4.69) (envelope-from ) id 1NnYjR-0006Sy-PY for kernel-team@lists.ubuntu.com; Fri, 05 Mar 2010 14:42:25 +0000 Received: from hutte.canonical.com ([91.189.90.181]) by adelie.canonical.com with esmtp (Exim 4.69 #1 (Debian)) id 1NnYjQ-0007LG-MY for ; Fri, 05 Mar 2010 14:42:24 +0000 Received: from 79-66-204-94.dynamic.dsl.as9105.com ([79.66.204.94] helo=localhost.localdomain) by hutte.canonical.com with esmtpsa (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.69) (envelope-from ) id 1NnYjQ-0004Vn-ID for kernel-team@lists.ubuntu.com; Fri, 05 Mar 2010 14:42:24 +0000 From: Andy Whitcroft To: kernel-team@lists.ubuntu.com Subject: [PATCH 1/2] KVM: introduce kvm_vcpu_on_spin Date: Fri, 5 Mar 2010 14:42:21 +0000 Message-Id: <1267800142-18169-2-git-send-email-apw@canonical.com> X-Mailer: git-send-email 1.7.0 In-Reply-To: <1267800142-18169-1-git-send-email-apw@canonical.com> References: <1267800142-18169-1-git-send-email-apw@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com From: Zhai, Edwin Introduce kvm_vcpu_on_spin, to be used by VMX/SVM to yield processing once the cpu detects pause-based looping. Signed-off-by: "Zhai, Edwin" Signed-off-by: Marcelo Tosatti Signed-off-by: Andy Whitcroft --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+), 0 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b7bbb5d..b5bcb4f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -266,6 +266,7 @@ int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn); void mark_page_dirty(struct kvm *kvm, gfn_t gfn); void kvm_vcpu_block(struct kvm_vcpu *vcpu); +void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu); void kvm_resched(struct kvm_vcpu *vcpu); void kvm_load_guest_fpu(struct kvm_vcpu *vcpu); void kvm_put_guest_fpu(struct kvm_vcpu *vcpu); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7495ce3..faa40d9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1705,6 +1705,21 @@ void kvm_resched(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_resched); +void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu) +{ + ktime_t expires; + DEFINE_WAIT(wait); + + prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); + + /* Sleep for 100 us, and hope lock-holder got scheduled */ + expires = ktime_add_ns(ktime_get(), 100000UL); + schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); + + finish_wait(&vcpu->wq, &wait); +} +EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin); + static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct kvm_vcpu *vcpu = vma->vm_file->private_data;