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 v2 Date: Mon, 15 Jun 2009 15:47:54 +0200 Message-ID: <1245073674-28998-4-git-send-email-ehrhardt@linux.vnet.ibm.com> References: <1245073674-28998-1-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 mtagate2.de.ibm.com ([195.212.17.162]:52769 "EHLO mtagate2.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752183AbZFONry (ORCPT ); Mon, 15 Jun 2009 09:47:54 -0400 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate2.de.ibm.com (8.13.1/8.13.1) with ESMTP id n5FDluw8023981 for ; Mon, 15 Jun 2009 13:47:56 GMT Received: from d12av01.megacenter.de.ibm.com (d12av01.megacenter.de.ibm.com [9.149.165.212]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n5FDluCP2609252 for ; Mon, 15 Jun 2009 15:47:56 +0200 Received: from d12av01.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av01.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n5FDltnr027488 for ; Mon, 15 Jun 2009 15:47:55 +0200 In-Reply-To: <1245073674-28998-1-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* - remove dependency to KVM_REQ_MMU_RELOAD in generic code - remove explicit barrier after test_and_clear_bit as it is implied - 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 | 6 ++++++ virt/kvm/kvm_main.c | 6 ++++++ 3 files changed, 32 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 +92,12 @@ 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)) { + 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 @@ -1681,6 +1681,12 @@ static int kvm_vcpu_mmap(struct file *fi static int kvm_vcpu_release(struct inode *inode, struct file *filp) { struct kvm_vcpu *vcpu = filp->private_data; + int i; + + vcpu->requests = 0; + smp_mb(); + for (i = 0; i < sizeof(vcpu->requests); i++) + wake_up_bit(&vcpu->requests, i); kvm_put_kvm(vcpu->kvm); return 0;