From patchwork Mon Jul 6 20:33:15 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gregory Haskins X-Patchwork-Id: 34308 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n66KXxid010701 for ; Mon, 6 Jul 2009 20:33:59 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754224AbZGFUdw (ORCPT ); Mon, 6 Jul 2009 16:33:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754636AbZGFUdv (ORCPT ); Mon, 6 Jul 2009 16:33:51 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:60733 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755181AbZGFUdu (ORCPT ); Mon, 6 Jul 2009 16:33:50 -0400 Received: from dev.haskins.net (prv-ext-foundry1.gns.novell.com [137.65.251.240]) by victor.provo.novell.com with ESMTP (TLS encrypted); Mon, 06 Jul 2009 14:33:43 -0600 Received: from dev.haskins.net (localhost [127.0.0.1]) by dev.haskins.net (Postfix) with ESMTP id F0D29464244; Mon, 6 Jul 2009 16:33:15 -0400 (EDT) From: Gregory Haskins Subject: [KVM PATCH v9 1/2] KVM: make io_bus interface more robust To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, mst@redhat.com, avi@redhat.com Date: Mon, 06 Jul 2009 16:33:15 -0400 Message-ID: <20090706203315.14222.25490.stgit@dev.haskins.net> In-Reply-To: <20090706202742.14222.65548.stgit@dev.haskins.net> References: <20090706202742.14222.65548.stgit@dev.haskins.net> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Today kvm_io_bus_regsiter_dev() returns void and will internally BUG_ON if it fails. We want to create dynamic MMIO/PIO entries driven from userspace later in the series, so we need to enhance the code to be more robust with the following changes: 1) Add a return value to the registration function 2) Fix up all the callsites to check the return code, handle any failures, and percolate the error up to the caller. 3) Add an unregister function that collapses holes in the array Signed-off-by: Gregory Haskins --- arch/x86/kvm/i8254.c | 22 ++++++++++++++++++++-- arch/x86/kvm/i8259.c | 9 ++++++++- include/linux/kvm_host.h | 10 +++++++--- virt/kvm/coalesced_mmio.c | 8 ++++++-- virt/kvm/ioapic.c | 8 ++++++-- virt/kvm/kvm_main.c | 41 ++++++++++++++++++++++++++++++++++++----- 6 files changed, 83 insertions(+), 15 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 8c3ac30..298312d 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -591,6 +591,7 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) { struct kvm_pit *pit; struct kvm_kpit_state *pit_state; + int ret; pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL); if (!pit) @@ -625,14 +626,31 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); kvm_iodevice_init(&pit->dev, &pit_dev_ops); - __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); + ret = __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); + if (ret < 0) + goto fail; if (flags & KVM_PIT_SPEAKER_DUMMY) { kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); - __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev); + ret = __kvm_io_bus_register_dev(&kvm->pio_bus, + &pit->speaker_dev); + if (ret < 0) + goto fail; } return pit; + +fail: + if (flags & KVM_PIT_SPEAKER_DUMMY) + __kvm_io_bus_unregister_dev(&kvm->pio_bus, &pit->speaker_dev); + + __kvm_io_bus_unregister_dev(&kvm->pio_bus, &pit->dev); + + if (pit->irq_source_id >= 0) + kvm_free_irq_source_id(kvm, pit->irq_source_id); + + kfree(pit); + return NULL; } void kvm_free_pit(struct kvm *kvm) diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 1d1bb75..670e426 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -536,6 +536,8 @@ static const struct kvm_io_device_ops picdev_ops = { struct kvm_pic *kvm_create_pic(struct kvm *kvm) { struct kvm_pic *s; + int ret; + s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL); if (!s) return NULL; @@ -552,6 +554,11 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm) * Initialize PIO device */ kvm_iodevice_init(&s->dev, &picdev_ops); - kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev); + ret = kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev); + if (ret < 0) { + kfree(s); + return NULL; + } + return s; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 8e04a34..306bc67 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -64,10 +64,14 @@ int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr, int len, const void *val); int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val); -void __kvm_io_bus_register_dev(struct kvm_io_bus *bus, +int __kvm_io_bus_register_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev); +int kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, + struct kvm_io_device *dev); +void __kvm_io_bus_unregister_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev); +void kvm_io_bus_unregister_dev(struct kvm *kvm, struct kvm_io_bus *bus, struct kvm_io_device *dev); -void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, - struct kvm_io_device *dev); struct kvm_vcpu { struct kvm *kvm; diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c index 0352f81..04d69cd 100644 --- a/virt/kvm/coalesced_mmio.c +++ b/virt/kvm/coalesced_mmio.c @@ -92,6 +92,7 @@ static const struct kvm_io_device_ops coalesced_mmio_ops = { int kvm_coalesced_mmio_init(struct kvm *kvm) { struct kvm_coalesced_mmio_dev *dev; + int ret; dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); if (!dev) @@ -100,9 +101,12 @@ int kvm_coalesced_mmio_init(struct kvm *kvm) kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); dev->kvm = kvm; kvm->coalesced_mmio_dev = dev; - kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev); - return 0; + ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev); + if (ret < 0) + kfree(dev); + + return ret; } int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 92496ff..048836d 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -340,6 +340,7 @@ static const struct kvm_io_device_ops ioapic_mmio_ops = { int kvm_ioapic_init(struct kvm *kvm) { struct kvm_ioapic *ioapic; + int ret; ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL); if (!ioapic) @@ -348,7 +349,10 @@ int kvm_ioapic_init(struct kvm *kvm) kvm_ioapic_reset(ioapic); kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops); ioapic->kvm = kvm; - kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev); - return 0; + ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev); + if (ret < 0) + kfree(ioapic); + + return ret; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 05b6bc7..11595c7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2533,21 +2533,52 @@ int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val) return -EOPNOTSUPP; } -void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, +int kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, struct kvm_io_device *dev) { + int ret; + down_write(&kvm->slots_lock); - __kvm_io_bus_register_dev(bus, dev); + ret = __kvm_io_bus_register_dev(bus, dev); up_write(&kvm->slots_lock); + + return ret; } /* An unlocked version. Caller must have write lock on slots_lock. */ -void __kvm_io_bus_register_dev(struct kvm_io_bus *bus, - struct kvm_io_device *dev) +int __kvm_io_bus_register_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev) { - BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1)); + if (bus->dev_count > (NR_IOBUS_DEVS-1)) + return -ENOSPC; bus->devs[bus->dev_count++] = dev; + + return 0; +} + +void kvm_io_bus_unregister_dev(struct kvm *kvm, + struct kvm_io_bus *bus, + struct kvm_io_device *dev) +{ + down_write(&kvm->slots_lock); + __kvm_io_bus_unregister_dev(bus, dev); + up_write(&kvm->slots_lock); +} + +/* An unlocked version. Caller must have write lock on slots_lock. */ +void __kvm_io_bus_unregister_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev) +{ + int i; + + for (i = 0; i < bus->dev_count; i++) { + + if (bus->devs[i] == dev) { + bus->devs[i] = bus->devs[--bus->dev_count]; + break; + } + } } static struct notifier_block kvm_cpu_notifier = {