From patchwork Mon Apr 12 10:35:35 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takuya Yoshikawa X-Patchwork-Id: 92027 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 o3CAW5ij002876 for ; Mon, 12 Apr 2010 10:32:05 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753404Ab0DLKcB (ORCPT ); Mon, 12 Apr 2010 06:32:01 -0400 Received: from serv2.oss.ntt.co.jp ([222.151.198.100]:35882 "EHLO serv2.oss.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753308Ab0DLKcA (ORCPT ); Mon, 12 Apr 2010 06:32:00 -0400 Received: from serv2.oss.ntt.co.jp (localhost [127.0.0.1]) by serv2.oss.ntt.co.jp (Postfix) with ESMTP id 5EB63248228; Mon, 12 Apr 2010 19:31:59 +0900 (JST) Received: from serv1.oss.ntt.co.jp (serv1.oss.ntt.co.jp [172.19.0.2]) by serv2.oss.ntt.co.jp (Postfix) with ESMTP id 4BD5D2481F3; Mon, 12 Apr 2010 19:31:59 +0900 (JST) Received: from yshtky3.kern.oss.ntt.co.jp (unknown [172.17.1.144]) by serv1.oss.ntt.co.jp (Postfix) with SMTP id 301ED261801; Mon, 12 Apr 2010 19:31:59 +0900 (JST) Date: Mon, 12 Apr 2010 19:35:35 +0900 From: Takuya Yoshikawa To: avi@redhat.com, mtosatti@redhat.com Cc: kvm@vger.kernel.org, kvm-ia64@vger.kernel.org, kvm-ppc@vger.kernel.org Subject: [PATCH] KVM: fix the handling of dirty bitmaps to avoid overflows Message-Id: <20100412193535.6c502695.yoshikawa.takuya@oss.ntt.co.jp> X-Mailer: Sylpheed 2.6.0 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Mon, 12 Apr 2010 10:32:09 +0000 (UTC) === Int is not long enough to store the size of a dirty bitmap. This patch fixes this problem with the introduction of a wrapper function to calculate the sizes of dirty bitmaps. Note: in mark_page_dirty(), we have to consider the fact that __set_bit() takes the offset as int, not long. Signed-off-by: Takuya Yoshikawa --- arch/ia64/kvm/kvm-ia64.c | 9 +++++---- arch/powerpc/kvm/book3s.c | 5 +++-- arch/x86/kvm/x86.c | 5 +++-- include/linux/kvm_host.h | 5 +++++ virt/kvm/kvm_main.c | 13 ++++++++----- 5 files changed, 24 insertions(+), 13 deletions(-) diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index b0ed80c..566aff6 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1806,7 +1806,8 @@ static int kvm_ia64_sync_dirty_log(struct kvm *kvm, { struct kvm_memory_slot *memslot; int r, i; - long n, base; + long base; + unsigned long n; unsigned long *dirty_bitmap = (unsigned long *)(kvm->arch.vm_base + offsetof(struct kvm_vm_data, kvm_mem_dirty_log)); @@ -1819,7 +1820,7 @@ static int kvm_ia64_sync_dirty_log(struct kvm *kvm, if (!memslot->dirty_bitmap) goto out; - n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; + n = kvm_dirty_bitmap_bytes(memslot); base = memslot->base_gfn / BITS_PER_LONG; for (i = 0; i < n/sizeof(long); ++i) { @@ -1835,7 +1836,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { int r; - int n; + unsigned long n; struct kvm_memory_slot *memslot; int is_dirty = 0; @@ -1854,7 +1855,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, if (is_dirty) { kvm_flush_remote_tlbs(kvm); memslot = &kvm->memslots->memslots[log->slot]; - n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; + n = kvm_dirty_bitmap_bytes(memslot); memset(memslot->dirty_bitmap, 0, n); } r = 0; diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index a7ab2ea..4ac7b15 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -1118,7 +1118,8 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_vcpu *vcpu; ulong ga, ga_end; int is_dirty = 0; - int r, n; + int r; + unsigned long n; mutex_lock(&kvm->slots_lock); @@ -1136,7 +1137,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, kvm_for_each_vcpu(n, vcpu, kvm) kvmppc_mmu_pte_pflush(vcpu, ga, ga_end); - n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; + n = kvm_dirty_bitmap_bytes(memslot); memset(memslot->dirty_bitmap, 0, n); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fd5c3d3..bb36c3c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2648,8 +2648,9 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm, int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { - int r, n, i; + int r, i; struct kvm_memory_slot *memslot; + unsigned long n; unsigned long is_dirty = 0; unsigned long *dirty_bitmap = NULL; @@ -2664,7 +2665,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, if (!memslot->dirty_bitmap) goto out; - n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; + n = kvm_dirty_bitmap_bytes(memslot); r = -ENOMEM; dirty_bitmap = vmalloc(n); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 8e91fa7..169d077 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -119,6 +119,11 @@ struct kvm_memory_slot { int user_alloc; }; +static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot) +{ + return ALIGN(memslot->npages, BITS_PER_LONG) / 8; +} + struct kvm_kernel_irq_routing_entry { u32 gsi; u32 type; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9379533..6fe79c4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -645,7 +645,7 @@ skip_lpage: /* Allocate page dirty bitmap if needed */ if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) { - unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8; + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(&new); new.dirty_bitmap = vmalloc(dirty_bytes); if (!new.dirty_bitmap) @@ -765,7 +765,7 @@ int kvm_get_dirty_log(struct kvm *kvm, { struct kvm_memory_slot *memslot; int r, i; - int n; + unsigned long n; unsigned long any = 0; r = -EINVAL; @@ -777,7 +777,7 @@ int kvm_get_dirty_log(struct kvm *kvm, if (!memslot->dirty_bitmap) goto out; - n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; + n = kvm_dirty_bitmap_bytes(memslot); for (i = 0; !any && i < n/sizeof(long); ++i) any = memslot->dirty_bitmap[i]; @@ -1183,10 +1183,13 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn) memslot = gfn_to_memslot_unaliased(kvm, gfn); if (memslot && memslot->dirty_bitmap) { unsigned long rel_gfn = gfn - memslot->base_gfn; + unsigned long *p = memslot->dirty_bitmap + + rel_gfn / BITS_PER_LONG; + int offset = rel_gfn % BITS_PER_LONG; /* avoid RMW */ - if (!generic_test_le_bit(rel_gfn, memslot->dirty_bitmap)) - generic___set_le_bit(rel_gfn, memslot->dirty_bitmap); + if (!generic_test_le_bit(offset, p)) + generic___set_le_bit(offset, p); } }