From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amos Kong Subject: [RESEND PATCH v5 1/2] KVM: resize kvm_io_range array dynamically Date: Wed, 07 Mar 2012 21:20:12 +0800 Message-ID: <20120307132012.27621.60400.stgit@dhcp-8-167.nay.redhat.com> References: <20120307131807.27621.19355.stgit@dhcp-8-167.nay.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: jasowang@redhat.com, mtosatti@redhat.com, alex.williamson@redhat.com, kvm@vger.kernel.org, levinsasha928@gmail.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:19761 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756103Ab2CGNUP (ORCPT ); Wed, 7 Mar 2012 08:20:15 -0500 In-Reply-To: <20120307131807.27621.19355.stgit@dhcp-8-167.nay.redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This patch makes the kvm_io_range array can be resized dynamically. Signed-off-by: Amos Kong --- include/linux/kvm_host.h | 5 +++-- virt/kvm/kvm_main.c | 40 +++++++++++++++++++++------------------- 2 files changed, 24 insertions(+), 21 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 355e445..e20dc8d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -67,10 +67,11 @@ struct kvm_io_range { struct kvm_io_device *dev; }; +#define NR_IOBUS_DEVS 300 + struct kvm_io_bus { int dev_count; -#define NR_IOBUS_DEVS 300 - struct kvm_io_range range[NR_IOBUS_DEVS]; + struct kvm_io_range range[]; }; enum kvm_bus { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e4431ad..a0261d9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2389,9 +2389,6 @@ int kvm_io_bus_sort_cmp(const void *p1, const void *p2) int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev, gpa_t addr, int len) { - if (bus->dev_count == NR_IOBUS_DEVS) - return -ENOSPC; - bus->range[bus->dev_count++] = (struct kvm_io_range) { .addr = addr, .len = len, @@ -2491,12 +2488,15 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, struct kvm_io_bus *new_bus, *bus; bus = kvm->buses[bus_idx]; - if (bus->dev_count > NR_IOBUS_DEVS-1) + if (bus->dev_count > NR_IOBUS_DEVS - 1) return -ENOSPC; - new_bus = kmemdup(bus, sizeof(struct kvm_io_bus), GFP_KERNEL); + new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) * + sizeof(struct kvm_io_range)), GFP_KERNEL); if (!new_bus) return -ENOMEM; + memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count * + sizeof(struct kvm_io_range))); kvm_io_bus_insert_dev(new_bus, dev, addr, len); rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); @@ -2513,26 +2513,28 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_bus *new_bus, *bus; bus = kvm->buses[bus_idx]; - - new_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL); - if (!new_bus) - return -ENOMEM; - r = -ENOENT; - for (i = 0; i < new_bus->dev_count; i++) - if (new_bus->range[i].dev == dev) { + for (i = 0; i < bus->dev_count; i++) + if (bus->range[i].dev == dev) { r = 0; - new_bus->dev_count--; - new_bus->range[i] = new_bus->range[new_bus->dev_count]; - sort(new_bus->range, new_bus->dev_count, - sizeof(struct kvm_io_range), - kvm_io_bus_sort_cmp, NULL); break; } - if (r) { - kfree(new_bus); + if (r) return r; + + new_bus = kmemdup(bus, sizeof(*bus) + ((bus->dev_count - 1) * + sizeof(struct kvm_io_range)), GFP_KERNEL); + if (!new_bus) + return -ENOMEM; + + new_bus->dev_count--; + /* copy last entry of bus->range to deleted entry spot if + deleted entry isn't the last entry of bus->range */ + if (i != bus->dev_count - 1) { + new_bus->range[i] = bus->range[bus->dev_count - 1]; + sort(new_bus->range, new_bus->dev_count, + sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp, NULL); } rcu_assign_pointer(kvm->buses[bus_idx], new_bus);