From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: [PATCH 6/7] KVM: MMU: clear unsync_child_bitmap completely Date: Fri, 11 Jun 2010 21:34:04 +0800 Message-ID: <4C123B4C.9010705@cn.fujitsu.com> References: <4C1239EE.3090904@cn.fujitsu.com> <4C123ABA.3000601@cn.fujitsu.com> <4C123AF2.80803@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM list To: Avi Kivity Return-path: In-Reply-To: <4C123AF2.80803@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org In current code, some page's unsync_child_bitmap is not cleared completely in mmu_sync_children(), for example, if two PDPEs shard one PDT, one of PDPE's unsync_child_bitmap is not cleared. Currently, it not harm anything just little overload, but it's the prepare work for the later patch Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 55 ++++++++++++++++++++++++++++----------------------- 1 files changed, 30 insertions(+), 25 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index c4b980a..eb20682 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1149,33 +1149,38 @@ static int __mmu_unsync_walk(struct kvm_mmu_page *sp, int i, ret, nr_unsync_leaf = 0; for_each_unsync_children(sp->unsync_child_bitmap, i) { + struct kvm_mmu_page *child; u64 ent = sp->spt[i]; - if (is_shadow_present_pte(ent) && !is_large_pte(ent)) { - struct kvm_mmu_page *child; - child = page_header(ent & PT64_BASE_ADDR_MASK); - - if (child->unsync_children) { - if (mmu_pages_add(pvec, child, i)) - return -ENOSPC; - - ret = __mmu_unsync_walk(child, pvec); - if (!ret) { - __clear_bit(i, sp->unsync_child_bitmap); - sp->unsync_children--; - WARN_ON((int)sp->unsync_children < 0); - } else if (ret > 0) - nr_unsync_leaf += ret; - else - return ret; - } + if (!is_shadow_present_pte(ent) || is_large_pte(ent)) + goto clear_child_bitmap; + + child = page_header(ent & PT64_BASE_ADDR_MASK); + + if (child->unsync_children) { + if (mmu_pages_add(pvec, child, i)) + return -ENOSPC; + + ret = __mmu_unsync_walk(child, pvec); + if (!ret) + goto clear_child_bitmap; + else if (ret > 0) + nr_unsync_leaf += ret; + else + return ret; + } else if (child->unsync) { + nr_unsync_leaf++; + if (mmu_pages_add(pvec, child, i)) + return -ENOSPC; + } else + goto clear_child_bitmap; - if (child->unsync) { - nr_unsync_leaf++; - if (mmu_pages_add(pvec, child, i)) - return -ENOSPC; - } - } + continue; + +clear_child_bitmap: + __clear_bit(i, sp->unsync_child_bitmap); + sp->unsync_children--; + WARN_ON((int)sp->unsync_children < 0); } -- 1.6.1.2