From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH] xen: domain_update_node_affinity: Correct the ASSERT Date: Fri, 25 Jul 2014 17:05:35 +0100 Message-ID: <53D2804F.3040404@citrix.com> References: <1406302204-13992-1-git-send-email-julien.grall@linaro.org> <53D27B5F.8020002@citrix.com> <53D27C30.7020908@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XAi06-00009a-8v for xen-devel@lists.xenproject.org; Fri, 25 Jul 2014 16:05:42 +0000 In-Reply-To: <53D27C30.7020908@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall , xen-devel@lists.xenproject.org Cc: Juergen Gross , Keir Fraser , ian.campbell@citrix.com, tim@xen.org, Dario Faggioli , Ian Jackson , George Dunlap , stefano.stabellini@citrix.com, Jan Beulich List-Id: xen-devel@lists.xenproject.org On 25/07/14 16:48, Julien Grall wrote: > On 07/25/2014 04:44 PM, Andrew Cooper wrote: >> On 25/07/14 16:30, Julien Grall wrote: >>> The commit "move domain to cpupool0 before destroying it" make Xen crashes >>> when a domain is destroyed with d->vcpus allocated but no VCPU initialized. >>> >>> Assertion '!cpumask_empty(dom_cpumask)' failed at domain.c:452 >>> Xen call trace: >>> [<00207bd8>] domain_update_node_affinity+0x10c/0x238 (PC) >>> [<00000004>] 00000004 (LR) >>> [<00226870>] sched_move_domain+0x3cc/0x42c >>> [<0020925c>] domain_kill+0xc8/0x178 >>> [<00206a0c>] do_domctl+0xaac/0x15e4 >>> [<002529c0>] do_trap_hypervisor+0xc5c/0xf94 >>> [<002559f0>] return_from_trap+0/0x4 >>> >>> Fix the ASSERT to check if d->vcpu is allocated and VCPU 0 is initialized. >>> >>> Signed-off-by: Julien Grall >>> Cc: George Dunlap >>> Cc: Dario Faggioli >>> Cc: Juergen Gross >>> Cc: Ian Campbell >>> Cc: Ian Jackson >>> Cc: Jan Beulich >>> Cc: Keir Fraser >>> Cc: Tim Deegan >>> >>> --- >>> This patch should be backported to Xen 4.4 >>> --- >>> xen/common/domain.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/xen/common/domain.c b/xen/common/domain.c >>> index d7a84cf..188b769 100644 >>> --- a/xen/common/domain.c >>> +++ b/xen/common/domain.c >>> @@ -449,7 +449,7 @@ void domain_update_node_affinity(struct domain *d) >>> } >>> /* Filter out non-online cpus */ >>> cpumask_and(dom_cpumask, dom_cpumask, online); >>> - ASSERT(!cpumask_empty(dom_cpumask)); >>> + ASSERT( !d->vcpu || !d->vcpu[0] || !cpumask_empty(dom_cpumask)); >> You don't actually care for the vcpu pointers themselves. You only care >> whether the domain has vcpus. >> >> d->max_vcpus == 0 is a more appropriate check. > Actually no... max_vcpus has been set before Xen is allocating > alloc_vcpu (see DOMCTL_max_vpus in common common/domctl.c). > > So if Xen fails to allocate VCPU0, the hypervisor will still crash when > the domain is killed. > > Regards, > Ah yes - I had mis-remembered the problem at hand. Sorry for the noise. ~Andrew