[34/40] KVM: convert io_bus to SRCU

Message ID	1265822589-11155-35-git-send-email-avi@redhat.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o1AHPlK5025690 for <patchwork-kvm@patchwork.kernel.org>; Wed, 10 Feb 2010 17:25:48 GMT From: Avi Kivity <avi@redhat.com> To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 34/40] KVM: convert io_bus to SRCU Date: Wed, 10 Feb 2010 19:23:03 +0200 Message-Id: <1265822589-11155-35-git-send-email-avi@redhat.com> In-Reply-To: <1265822589-11155-1-git-send-email-avi@redhat.com> References: <1265822589-11155-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index b2e4d16..d0ad538 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -241,10 +241,10 @@ static int handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) return 0; mmio: if (p->dir) - r = kvm_io_bus_read(&vcpu->kvm->mmio_bus, p->addr, + r = kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, p->addr, p->size, &p->data); else - r = kvm_io_bus_write(&vcpu->kvm->mmio_bus, p->addr, + r = kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, p->addr, p->size, &p->data); if (r) printk(KERN_ERR"kvm: No iodevice found! addr:%lx\n", p->addr); diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 296aba4..a7259e8 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -642,13 +642,13 @@ 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); - ret = __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); + ret = kvm_io_bus_register_dev(kvm, 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); - ret = __kvm_io_bus_register_dev(&kvm->pio_bus, + ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, &pit->speaker_dev); if (ret < 0) goto fail_unregister; @@ -657,7 +657,7 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) return pit; fail_unregister: - __kvm_io_bus_unregister_dev(&kvm->pio_bus, &pit->dev); + kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); fail: if (pit->irq_source_id >= 0) diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index d057c0c..b7d145b 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -533,7 +533,9 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm) * Initialize PIO device */ kvm_iodevice_init(&s->dev, &picdev_ops); - ret = kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev); + down_write(&kvm->slots_lock); + ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, &s->dev); + up_write(&kvm->slots_lock); if (ret < 0) { kfree(s); return NULL; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 59f4da4..b9adeae 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2852,7 +2852,7 @@ static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len, !kvm_iodevice_write(&vcpu->arch.apic->dev, addr, len, v)) return 0; - return kvm_io_bus_write(&vcpu->kvm->mmio_bus, addr, len, v); + return kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, addr, len, v); } static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v) @@ -2861,7 +2861,7 @@ static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v) !kvm_iodevice_read(&vcpu->arch.apic->dev, addr, len, v)) return 0; - return kvm_io_bus_read(&vcpu->kvm->mmio_bus, addr, len, v); + return kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, addr, len, v); } static int kvm_read_guest_virt(gva_t addr, void *val, unsigned int bytes, @@ -3346,11 +3346,12 @@ static int kernel_pio(struct kvm_vcpu *vcpu, void *pd) int r; if (vcpu->arch.pio.in) - r = kvm_io_bus_read(&vcpu->kvm->pio_bus, vcpu->arch.pio.port, + r = kvm_io_bus_read(vcpu->kvm, KVM_PIO_BUS, vcpu->arch.pio.port, vcpu->arch.pio.size, pd); else - r = kvm_io_bus_write(&vcpu->kvm->pio_bus, vcpu->arch.pio.port, - vcpu->arch.pio.size, pd); + r = kvm_io_bus_write(vcpu->kvm, KVM_PIO_BUS, + vcpu->arch.pio.port, vcpu->arch.pio.size, + pd); return r; } @@ -3361,7 +3362,7 @@ static int pio_string_write(struct kvm_vcpu *vcpu) int i, r = 0; for (i = 0; i < io->cur_count; i++) { - if (kvm_io_bus_write(&vcpu->kvm->pio_bus, + if (kvm_io_bus_write(vcpu->kvm, KVM_PIO_BUS, io->port, io->size, pd)) { r = -EOPNOTSUPP; break; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 20941c0..5e9cb90 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -57,20 +57,20 @@ struct kvm_io_bus { struct kvm_io_device *devs[NR_IOBUS_DEVS]; }; -void kvm_io_bus_init(struct kvm_io_bus *bus); -void kvm_io_bus_destroy(struct kvm_io_bus *bus); -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, +enum kvm_bus { + KVM_MMIO_BUS, + KVM_PIO_BUS, + KVM_NR_BUSES +}; + +int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, const void *val); +int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val); -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, +int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, 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); +int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, + struct kvm_io_device *dev); struct kvm_vcpu { struct kvm *kvm; @@ -171,8 +171,7 @@ struct kvm { atomic_t online_vcpus; struct list_head vm_list; struct mutex lock; - struct kvm_io_bus mmio_bus; - struct kvm_io_bus pio_bus; + struct kvm_io_bus *buses[KVM_NR_BUSES]; #ifdef CONFIG_HAVE_KVM_EVENTFD struct { spinlock_t lock; diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c index d68e6c6..a736a93 100644 --- a/virt/kvm/coalesced_mmio.c +++ b/virt/kvm/coalesced_mmio.c @@ -110,7 +110,9 @@ int kvm_coalesced_mmio_init(struct kvm *kvm) dev->kvm = kvm; kvm->coalesced_mmio_dev = dev; - ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev); + down_write(&kvm->slots_lock); + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev); + up_write(&kvm->slots_lock); if (ret < 0) goto out_free_dev; diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index a9d3fc6..315a586 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -463,7 +463,7 @@ static int kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) { int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO; - struct kvm_io_bus *bus = pio ? &kvm->pio_bus : &kvm->mmio_bus; + enum kvm_bus bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS; struct _ioeventfd *p; struct eventfd_ctx *eventfd; int ret; @@ -518,7 +518,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) kvm_iodevice_init(&p->dev, &ioeventfd_ops); - ret = __kvm_io_bus_register_dev(bus, &p->dev); + ret = kvm_io_bus_register_dev(kvm, bus_idx, &p->dev); if (ret < 0) goto unlock_fail; @@ -542,7 +542,7 @@ static int kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) { int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO; - struct kvm_io_bus *bus = pio ? &kvm->pio_bus : &kvm->mmio_bus; + enum kvm_bus bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS; struct _ioeventfd *p, *tmp; struct eventfd_ctx *eventfd; int ret = -ENOENT; @@ -565,7 +565,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) if (!p->wildcard && p->datamatch != args->datamatch) continue; - __kvm_io_bus_unregister_dev(bus, &p->dev); + kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev); ioeventfd_release(p); ret = 0; break; diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 38a2d20..f326a6f 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -372,7 +372,9 @@ int kvm_ioapic_init(struct kvm *kvm) kvm_ioapic_reset(ioapic); kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops); ioapic->kvm = kvm; - ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev); + down_write(&kvm->slots_lock); + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &ioapic->dev); + up_write(&kvm->slots_lock); if (ret < 0) kfree(ioapic); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c680f7b..659bc12 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -85,6 +85,8 @@ static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, static int hardware_enable_all(void); static void hardware_disable_all(void); +static void kvm_io_bus_destroy(struct kvm_io_bus *bus); + static bool kvm_rebooting; static bool largepages_enabled = true; @@ -367,7 +369,7 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) static struct kvm *kvm_create_vm(void) { - int r = 0; + int r = 0, i; struct kvm *kvm = kvm_arch_create_vm(); #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET struct page *page; @@ -391,6 +393,14 @@ static struct kvm *kvm_create_vm(void) goto out_err; if (init_srcu_struct(&kvm->srcu)) goto out_err; + for (i = 0; i < KVM_NR_BUSES; i++) { + kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus), + GFP_KERNEL); + if (!kvm->buses[i]) { + cleanup_srcu_struct(&kvm->srcu); + goto out_err; + } + } #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET page = alloc_page(GFP_KERNEL | __GFP_ZERO); @@ -416,11 +426,9 @@ static struct kvm *kvm_create_vm(void) atomic_inc(&kvm->mm->mm_count); spin_lock_init(&kvm->mmu_lock); spin_lock_init(&kvm->requests_lock); - kvm_io_bus_init(&kvm->pio_bus); kvm_eventfd_init(kvm); mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock); - kvm_io_bus_init(&kvm->mmio_bus); init_rwsem(&kvm->slots_lock); atomic_set(&kvm->users_count, 1); spin_lock(&kvm_lock); @@ -435,6 +443,8 @@ out: out_err: hardware_disable_all(); out_err_nodisable: + for (i = 0; i < KVM_NR_BUSES; i++) + kfree(kvm->buses[i]); kfree(kvm->memslots); kfree(kvm); return ERR_PTR(r); @@ -480,6 +490,7 @@ void kvm_free_physmem(struct kvm *kvm) static void kvm_destroy_vm(struct kvm *kvm) { + int i; struct mm_struct *mm = kvm->mm; kvm_arch_sync_events(kvm); @@ -487,8 +498,8 @@ static void kvm_destroy_vm(struct kvm *kvm) list_del(&kvm->vm_list); spin_unlock(&kvm_lock); kvm_free_irq_routing(kvm); - kvm_io_bus_destroy(&kvm->pio_bus); - kvm_io_bus_destroy(&kvm->mmio_bus); + for (i = 0; i < KVM_NR_BUSES; i++) + kvm_io_bus_destroy(kvm->buses[i]); kvm_coalesced_mmio_free(kvm); #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); @@ -1949,12 +1960,7 @@ static struct notifier_block kvm_reboot_notifier = { .priority = 0, }; -void kvm_io_bus_init(struct kvm_io_bus *bus) -{ - memset(bus, 0, sizeof(*bus)); -} - -void kvm_io_bus_destroy(struct kvm_io_bus *bus) +static void kvm_io_bus_destroy(struct kvm_io_bus *bus) { int i; @@ -1963,13 +1969,15 @@ void kvm_io_bus_destroy(struct kvm_io_bus *bus) kvm_iodevice_destructor(pos); } + kfree(bus); } /* kvm_io_bus_write - called under kvm->slots_lock */ -int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr, +int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val) { int i; + struct kvm_io_bus *bus = rcu_dereference(kvm->buses[bus_idx]); for (i = 0; i < bus->dev_count; i++) if (!kvm_iodevice_write(bus->devs[i], addr, len, val)) return 0; @@ -1977,59 +1985,71 @@ int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr, } /* kvm_io_bus_read - called under kvm->slots_lock */ -int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val) +int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, void *val) { int i; + struct kvm_io_bus *bus = rcu_dereference(kvm->buses[bus_idx]); + for (i = 0; i < bus->dev_count; i++) if (!kvm_iodevice_read(bus->devs[i], addr, len, val)) return 0; return -EOPNOTSUPP; } -int kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, - struct kvm_io_device *dev) +/* Caller must have write lock on slots_lock. */ +int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, + struct kvm_io_device *dev) { - int ret; - - down_write(&kvm->slots_lock); - ret = __kvm_io_bus_register_dev(bus, dev); - up_write(&kvm->slots_lock); + struct kvm_io_bus *new_bus, *bus; - return ret; -} - -/* An unlocked version. Caller must have write lock on slots_lock. */ -int __kvm_io_bus_register_dev(struct kvm_io_bus *bus, - struct kvm_io_device *dev) -{ + bus = kvm->buses[bus_idx]; if (bus->dev_count > NR_IOBUS_DEVS-1) return -ENOSPC; - bus->devs[bus->dev_count++] = dev; + new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL); + if (!new_bus) + return -ENOMEM; + memcpy(new_bus, bus, sizeof(struct kvm_io_bus)); + new_bus->devs[new_bus->dev_count++] = dev; + rcu_assign_pointer(kvm->buses[bus_idx], new_bus); + synchronize_srcu_expedited(&kvm->srcu); + kfree(bus); return 0; } -void kvm_io_bus_unregister_dev(struct kvm *kvm, - struct kvm_io_bus *bus, - struct kvm_io_device *dev) +/* Caller must have write lock on slots_lock. */ +int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, + struct kvm_io_device *dev) { - down_write(&kvm->slots_lock); - __kvm_io_bus_unregister_dev(bus, dev); - up_write(&kvm->slots_lock); -} + int i, r; + struct kvm_io_bus *new_bus, *bus; -/* 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; + new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL); + if (!new_bus) + return -ENOMEM; - for (i = 0; i < bus->dev_count; i++) - if (bus->devs[i] == dev) { - bus->devs[i] = bus->devs[--bus->dev_count]; + bus = kvm->buses[bus_idx]; + memcpy(new_bus, bus, sizeof(struct kvm_io_bus)); + + r = -ENOENT; + for (i = 0; i < new_bus->dev_count; i++) + if (new_bus->devs[i] == dev) { + r = 0; + new_bus->devs[i] = new_bus->devs[--new_bus->dev_count]; break; } + + if (r) { + kfree(new_bus); + return r; + } + + rcu_assign_pointer(kvm->buses[bus_idx], new_bus); + synchronize_srcu_expedited(&kvm->srcu); + kfree(bus); + return r; } static struct notifier_block kvm_cpu_notifier = {

[34/40] KVM: convert io_bus to SRCU

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