From patchwork Thu Apr 23 15:14:41 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gregory Haskins X-Patchwork-Id: 19649 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 n3NFFq8G015417 for ; Thu, 23 Apr 2009 15:15:52 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759513AbZDWPPB (ORCPT ); Thu, 23 Apr 2009 11:15:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759467AbZDWPPB (ORCPT ); Thu, 23 Apr 2009 11:15:01 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:44279 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757999AbZDWPO6 (ORCPT ); Thu, 23 Apr 2009 11:14:58 -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); Thu, 23 Apr 2009 09:14:43 -0600 Received: from dev.haskins.net (localhost [127.0.0.1]) by dev.haskins.net (Postfix) with ESMTP id EC4BE464229; Thu, 23 Apr 2009 11:14:41 -0400 (EDT) From: Gregory Haskins Subject: [KVM PATCH 3/3] kvm: add support for irqfd via eventfd-notification interface To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, avi@redhat.com, davidel@xmailserver.org Date: Thu, 23 Apr 2009 11:14:41 -0400 Message-ID: <20090423151441.14094.22549.stgit@dev.haskins.net> In-Reply-To: <20090423150910.14094.73708.stgit@dev.haskins.net> References: <20090423150910.14094.73708.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 This allows an eventfd to be registered as an irq source with a guest. Any signaling operation on the eventfd (via userspace or kernel) will inject the registered GSI at the next available window. Signed-off-by: Gregory Haskins --- arch/x86/kvm/Makefile | 2 - arch/x86/kvm/x86.c | 1 include/linux/kvm.h | 7 ++ include/linux/kvm_host.h | 7 ++ virt/kvm/irqfd.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++ virt/kvm/kvm_main.c | 12 ++++ 6 files changed, 161 insertions(+), 1 deletions(-) create mode 100644 virt/kvm/irqfd.c -- 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/Makefile b/arch/x86/kvm/Makefile index b43c4ef..d5fff51 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -3,7 +3,7 @@ # common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o \ - coalesced_mmio.o irq_comm.o) + coalesced_mmio.o irq_comm.o irqfd.o) ifeq ($(CONFIG_KVM_TRACE),y) common-objs += $(addprefix ../../../virt/kvm/, kvm_trace.o) endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8cb8542..88c45e6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1027,6 +1027,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_REINJECT_CONTROL: case KVM_CAP_IRQ_INJECT_STATUS: case KVM_CAP_ASSIGN_DEV_IRQ: + case KVM_CAP_IRQFD: r = 1; break; case KVM_CAP_COALESCED_MMIO: diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 3db5d8d..2404775 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -415,6 +415,7 @@ struct kvm_trace_rec { #define KVM_CAP_ASSIGN_DEV_IRQ 29 /* Another bug in KVM_SET_USER_MEMORY_REGION fixed: */ #define KVM_CAP_JOIN_MEMORY_REGIONS_WORKS 30 +#define KVM_CAP_IRQFD 31 #ifdef KVM_CAP_IRQ_ROUTING @@ -454,6 +455,11 @@ struct kvm_irq_routing { #endif +struct kvm_irqfd { + __u32 fd; + __u32 gsi; +}; + /* * ioctls for VM fds */ @@ -498,6 +504,7 @@ struct kvm_irq_routing { #define KVM_ASSIGN_SET_MSIX_ENTRY \ _IOW(KVMIO, 0x74, struct kvm_assigned_msix_entry) #define KVM_DEASSIGN_DEV_IRQ _IOW(KVMIO, 0x75, struct kvm_assigned_irq) +#define KVM_ASSIGN_IRQFD _IOW(KVMIO, 0x76, struct kvm_irqfd) /* * ioctls for vcpu fds diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 095ebb6..57f8dfe 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -134,6 +134,10 @@ struct kvm { struct list_head vm_list; struct kvm_io_bus mmio_bus; struct kvm_io_bus pio_bus; + struct { + struct list_head items; + int src; + } irqfd; struct kvm_vm_stat stat; struct kvm_arch arch; atomic_t users_count; @@ -524,4 +528,7 @@ static inline void kvm_free_irq_routing(struct kvm *kvm) {} #endif +int kvm_irqfd_assign(struct kvm *kvm, int fd, int gsi); +void kvm_irqfd_release(struct kvm *kvm); + #endif diff --git a/virt/kvm/irqfd.c b/virt/kvm/irqfd.c new file mode 100644 index 0000000..d6829b3 --- /dev/null +++ b/virt/kvm/irqfd.c @@ -0,0 +1,133 @@ +/* + * irqfd: Allows an eventfd to be used to inject an interrupt to the guest + * + * Credit goes to Avi Kivity for the original idea. + * + * Copyright 2009 Novell. All Rights Reserved. + * + * Author: + * Gregory Haskins + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include +#include +#include +#include +#include +#include + +struct _irqfd { + struct kvm *kvm; + int gsi; + struct file *file; + struct list_head list; + struct notifier_block nb; + struct work_struct work; +}; + +static void +irqfd_deferred_inject(struct work_struct *work) +{ + struct _irqfd *irqfd = container_of(work, struct _irqfd, work); + struct kvm *kvm = irqfd->kvm; + + mutex_lock(&kvm->lock); + kvm_set_irq(kvm, kvm->irqfd.src, irqfd->gsi, 1); + mutex_unlock(&kvm->lock); +} + +static int +irqfd_inject(struct notifier_block *nb, unsigned long nr, void *val) +{ + struct _irqfd *irqfd = container_of(nb, struct _irqfd, nb); + + /* + * The eventfd calls its notifier chain with interrupts disabled, + * so we need to defer the IRQ injection until later since we need + * to acquire the kvm->lock to do so. + */ + schedule_work(&irqfd->work); + + return 0; +} + +int +kvm_irqfd_assign(struct kvm *kvm, int fd, int gsi) +{ + struct _irqfd *irqfd; + int ret; + + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); + if (!irqfd) + return -ENOMEM; + + irqfd->kvm = kvm; + irqfd->gsi = gsi; + INIT_LIST_HEAD(&irqfd->list); + irqfd->nb.notifier_call = &irqfd_inject; + irqfd->nb.priority = 0; + INIT_WORK(&irqfd->work, irqfd_deferred_inject); + + /* + * note: this acquires a reference to the fd that we are responsible + * for dropping later + */ + irqfd->file = eventfd_notifier_register(fd, &irqfd->nb); + if (IS_ERR(irqfd->file)) { + ret = PTR_ERR(irqfd->file); + goto fail; + } + + mutex_lock(&kvm->lock); + if (kvm->irqfd.src == -1) { + ret = kvm_request_irq_source_id(kvm); + BUG_ON(ret < 0); + + kvm->irqfd.src = ret; + } + + list_add_tail(&irqfd->list, &kvm->irqfd.items); + + mutex_unlock(&kvm->lock); + + return 0; + +fail: + kfree(irqfd); + return ret; +} + +void +kvm_irqfd_release(struct kvm *kvm) +{ + struct _irqfd *irqfd, *tmp; + int ret; + + list_for_each_entry_safe(irqfd, tmp, &kvm->irqfd.items, list) { + ret = eventfd_notifier_unregister(irqfd->file, &irqfd->nb); + BUG_ON(ret < 0); + + flush_work(&irqfd->work); + fput(irqfd->file); + + list_del(&irqfd->list); + kfree(irqfd); + } + + if (kvm->irqfd.src != -1) + kvm_free_irq_source_id(kvm, kvm->irqfd.src); + +} diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3265566..c822d79 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -972,6 +972,8 @@ static struct kvm *kvm_create_vm(void) atomic_inc(&kvm->mm->mm_count); spin_lock_init(&kvm->mmu_lock); kvm_io_bus_init(&kvm->pio_bus); + INIT_LIST_HEAD(&kvm->irqfd.items); + kvm->irqfd.src = -1; mutex_init(&kvm->lock); kvm_io_bus_init(&kvm->mmio_bus); init_rwsem(&kvm->slots_lock); @@ -1023,6 +1025,7 @@ static void kvm_destroy_vm(struct kvm *kvm) spin_lock(&kvm_lock); list_del(&kvm->vm_list); spin_unlock(&kvm_lock); + kvm_irqfd_release(kvm); kvm_free_irq_routing(kvm); kvm_io_bus_destroy(&kvm->pio_bus); kvm_io_bus_destroy(&kvm->mmio_bus); @@ -2197,6 +2200,15 @@ static long kvm_vm_ioctl(struct file *filp, } #endif #endif /* KVM_CAP_IRQ_ROUTING */ + case KVM_ASSIGN_IRQFD: { + struct kvm_irqfd data; + + r = -EFAULT; + if (copy_from_user(&data, argp, sizeof data)) + goto out; + r = kvm_irqfd_assign(kvm, data.fd, data.gsi); + break; + } default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); }