From mboxrd@z Thu Jan 1 00:00:00 1970 From: ehrhardt@linux.vnet.ibm.com Subject: [PATCH 3/3] kvm-s390: streamline memslot handling - rebased Date: Tue, 2 Jun 2009 16:26:11 +0200 Message-ID: <1243952771-32428-4-git-send-email-ehrhardt@linux.vnet.ibm.com> References: <1243952771-32428-1-git-send-email-ehrhardt@linux.vnet.ibm.com> Cc: ehrhardt@linux.vnet.ibm.com, borntraeger@de.ibm.com, cotte@de.ibm.com, heiko.carstens@de.ibm.com, schwidefsky@de.ibm.com, mtosatti@redhat.com To: kvm@vger.kernel.org, avi@redhat.com Return-path: Received: from mtagate6.uk.ibm.com ([195.212.29.139]:58724 "EHLO mtagate6.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752479AbZFBO0M (ORCPT ); Tue, 2 Jun 2009 10:26:12 -0400 Received: from d06nrmr1707.portsmouth.uk.ibm.com (d06nrmr1707.portsmouth.uk.ibm.com [9.149.39.225]) by mtagate6.uk.ibm.com (8.14.3/8.13.8) with ESMTP id n52EQDdU784308 for ; Tue, 2 Jun 2009 14:26:13 GMT Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by d06nrmr1707.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n52EQDj91392674 for ; Tue, 2 Jun 2009 15:26:13 +0100 Received: from d06av01.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n52EQDMA025396 for ; Tue, 2 Jun 2009 15:26:13 +0100 In-Reply-To: <1243952771-32428-1-git-send-email-ehrhardt@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: From: Christian Ehrhardt As requested this is a rebased patch on top of the already applied v3 of the patch series. *updates to applied version* - ensure the wait_on_bit waiter is notified - ensure dropping vcpu all requests while freeing a vcpu - kickout only scheduled vcpus (its superfluous and wait might hang forever on not running vcpus) - kvm_arch_set_memory_region waits until the bit is consumed by the vcpu This patch relocates the variables kvm-s390 uses to track guest mem addr/size. As discussed dropping the variables at struct kvm_arch level allows to use the common vcpu->request based mechanism to reload guest memory if e.g. changes via set_memory_region. The kick mechanism introduced in this series is used to ensure running vcpus leave guest state to catch the update. Signed-off-by: Christian Ehrhardt --- [diffstat] arch/s390/kvm/kvm-s390.c | 27 ++++++++++++++++++++------- arch/s390/kvm/kvm-s390.h | 7 +++++++ virt/kvm/kvm_main.c | 4 ++++ 3 files changed, 31 insertions(+), 7 deletions(-) Index: kvm/arch/s390/kvm/kvm-s390.c =================================================================== --- kvm.orig/arch/s390/kvm/kvm-s390.c +++ kvm/arch/s390/kvm/kvm-s390.c @@ -674,6 +674,12 @@ long kvm_arch_vcpu_ioctl(struct file *fi return -EINVAL; } +static int wait_bit_schedule(void *word) +{ + schedule(); + return 0; +} + /* Section: memory related */ int kvm_arch_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem, @@ -681,6 +687,7 @@ int kvm_arch_set_memory_region(struct kv int user_alloc) { int i; + struct kvm_vcpu *vcpu; /* A few sanity checks. We can have exactly one memory slot which has to start at guest virtual zero and which has to be located at a @@ -706,13 +713,19 @@ int kvm_arch_set_memory_region(struct kv /* request update of sie control block for all available vcpus */ for (i = 0; i < KVM_MAX_VCPUS; ++i) { - if (kvm->vcpus[i]) { - if (test_and_set_bit(KVM_REQ_MMU_RELOAD, - &kvm->vcpus[i]->requests)) - continue; - kvm_s390_inject_sigp_stop(kvm->vcpus[i], - ACTION_VCPUREQUEST_ON_STOP); - } + vcpu = kvm->vcpus[i]; + if (!vcpu) + continue; + + if (!test_and_set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests)) + continue; + + if (vcpu->cpu == -1) + continue; + + kvm_s390_inject_sigp_stop(vcpu, ACTION_VCPUREQUEST_ON_STOP); + wait_on_bit(&vcpu->requests, KVM_REQ_MMU_RELOAD, + wait_bit_schedule, TASK_UNINTERRUPTIBLE); } return 0; Index: kvm/arch/s390/kvm/kvm-s390.h =================================================================== --- kvm.orig/arch/s390/kvm/kvm-s390.h +++ kvm/arch/s390/kvm/kvm-s390.h @@ -92,6 +92,13 @@ static inline unsigned long kvm_s390_han if (!vcpu->requests) return 0; + /* requests that can be handled at all levels */ + if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests)) { + smp_mb__after_clear_bit(); + wake_up_bit(&vcpu->requests, KVM_REQ_MMU_RELOAD); + kvm_s390_vcpu_set_mem(vcpu); + } + return vcpu->requests; } Index: kvm/virt/kvm/kvm_main.c =================================================================== --- kvm.orig/virt/kvm/kvm_main.c +++ kvm/virt/kvm/kvm_main.c @@ -1682,6 +1682,10 @@ static int kvm_vcpu_release(struct inode { struct kvm_vcpu *vcpu = filp->private_data; + clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests); + smp_mb__after_clear_bit(); + wake_up_bit(&vcpu->requests, KVM_REQ_MMU_RELOAD); + kvm_put_kvm(vcpu->kvm); return 0; }