From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH] kvm: Fix overlapping check for memory slots Date: Mon, 13 Apr 2009 13:47:28 +0800 Message-ID: <200904131347.29389.sheng@linux.intel.com> References: <49E06754.8050906@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Jan Kiszka , Glauber Costa , "qemu-devel" To: Avi Kivity Return-path: Received: from mga07.intel.com ([143.182.124.22]:26534 "EHLO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753434AbZDMFre (ORCPT ); Mon, 13 Apr 2009 01:47:34 -0400 In-Reply-To: <49E06754.8050906@web.de> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Saturday 11 April 2009 17:48:04 Jan Kiszka wrote: > This nice little buglet complicates a smarter slot management in qemu > user space just "slightly". Sigh... > > --------> > > When checking for overlapping slots on registration of a new one, kvm > currently also considers zero-length (ie. deleted) slots and rejects > requests incorrectly. This finally denies user space from joining slots. > Fix the check by skipping deleted slots. > > Signed-off-by: Jan Kiszka > --- > > virt/kvm/kvm_main.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 363af32..18f06d2 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1117,7 +1117,7 @@ int __kvm_set_memory_region(struct kvm *kvm, > for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { > struct kvm_memory_slot *s = &kvm->memslots[i]; > > - if (s == memslot) > + if (s == memslot || !s->npages) > continue; > if (!((base_gfn + npages <= s->base_gfn) || > (base_gfn >= s->base_gfn + s->npages))) Is it necessary to preserve a valid base_gfn/flags/etc for a zeroed slot? Seems kvm_free_physmem_slot didn't clean them. -- regards Yang, Sheng