From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH for-4.5 v3] x86/hvm: remove stray lock release from hvm_ioreq_server_init() Date: Fri, 26 Sep 2014 13:35:58 -0400 Message-ID: <20140926173558.GC5102@laptop.dumpdata.com> References: <1411741252-28366-1-git-send-email-vkuznets@redhat.com> <9AAE0902D5BC7E449B7C8E4E778ABCD04936F1@AMSPEX01CL01.citrite.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XXZR9-0008PR-99 for xen-devel@lists.xenproject.org; Fri, 26 Sep 2014 17:36:07 +0000 Content-Disposition: inline In-Reply-To: <9AAE0902D5BC7E449B7C8E4E778ABCD04936F1@AMSPEX01CL01.citrite.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Paul Durrant Cc: "xen-devel@lists.xenproject.org" , Vitaly Kuznetsov , Andrew Jones , Jan Beulich , Ian Campbell List-Id: xen-devel@lists.xenproject.org On Fri, Sep 26, 2014 at 02:43:38PM +0000, Paul Durrant wrote: > > -----Original Message----- > > From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com] > > Sent: 26 September 2014 15:21 > > To: xen-devel@lists.xenproject.org > > Cc: Paul Durrant; Ian Campbell; Jan Beulich; Andrew Jones > > Subject: [PATCH for-4.5 v3] x86/hvm: remove stray lock release from > > hvm_ioreq_server_init() > > > > If HVM_PARAM_IOREQ_PFN, HVM_PARAM_BUFIOREQ_PFN, or > > HVM_PARAM_BUFIOREQ_EVTCHN > > parameters are read when guest domain is dying it leads to the following > > ASSERT: > > > > (XEN) Assertion '_raw_spin_is_locked(lock)' failed at > > ...workspace/KERNEL/xen/xen/include/asm/spinlock.h:18 > > (XEN) ----[ Xen-4.5-unstable x86_64 debug=y Not tainted ]---- > > ... > > (XEN) Xen call trace: > > (XEN) [] _spin_unlock+0x27/0x30 > > (XEN) [] hvm_create_ioreq_server+0x3df/0x49a > > (XEN) [] do_hvm_op+0x12bf/0x27a0 > > (XEN) [] syscall_enter+0xeb/0x145 > > > > The root cause of this issue is the fact that ioreq_server.lock is being > > released twice - first in hvm_ioreq_server_init() and then in > > hvm_create_ioreq_server(). > > Drop the lock release from hvm_ioreq_server_init() as we don't take it here, > > do minor > > label cleanup. > > > > Signed-off-by: Vitaly Kuznetsov > > Looks good to me. > > Reviewed-by: Paul Durrant And Released-Acked-by: Konrad Rzeszutek Wilk > > > --- > > Changes from v1: > > - Instead of protecting agains creating ioreq server while guest domain > > is dying remove stray ioreq_server.lock lock release > > from hvm_ioreq_server_init(). Rename the patch accordingly. > > [Paul Durrant] > > > > Changes from v2: > > - Cleanup labels in hvm_ioreq_server_init(), shorten patch name > > [Jan Beulich] > > --- > > xen/arch/x86/hvm/hvm.c | 12 +++++------- > > 1 file changed, 5 insertions(+), 7 deletions(-) > > > > diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c > > index 0a20cbe..94c58e1 100644 > > --- a/xen/arch/x86/hvm/hvm.c > > +++ b/xen/arch/x86/hvm/hvm.c > > @@ -970,30 +970,28 @@ static int hvm_ioreq_server_init(struct > > hvm_ioreq_server *s, struct domain *d, > > > > rc = hvm_ioreq_server_alloc_rangesets(s, is_default); > > if ( rc ) > > - goto fail1; > > + return rc; > > > > rc = hvm_ioreq_server_map_pages(s, is_default, handle_bufioreq); > > if ( rc ) > > - goto fail2; > > + goto fail_map; > > > > for_each_vcpu ( d, v ) > > { > > rc = hvm_ioreq_server_add_vcpu(s, is_default, v); > > if ( rc ) > > - goto fail3; > > + goto fail_add; > > } > > > > return 0; > > > > - fail3: > > + fail_add: > > hvm_ioreq_server_remove_all_vcpus(s); > > hvm_ioreq_server_unmap_pages(s, is_default); > > > > - fail2: > > + fail_map: > > hvm_ioreq_server_free_rangesets(s, is_default); > > > > - fail1: > > - spin_unlock(&d->arch.hvm_domain.ioreq_server.lock); > > return rc; > > } > > > > -- > > 1.9.3 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel