Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423482AbbEENUb (ORCPT ); Tue, 5 May 2015 09:20:31 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:25379 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423394AbbEENUW (ORCPT ); Tue, 5 May 2015 09:20:22 -0400 Message-ID: <5548C366.1000509@huawei.com> Date: Tue, 5 May 2015 21:19:34 +0800 From: "Ouyang Zhaowei (Charles)" User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: David Vrabel , Boris Ostrovsky , Konrad Rzeszutek Wilk CC: , Dingweiping , Yanqiangjun , Subject: Re: [RESEND PATCH] xen: vcpu_info would be reset to wrong place on canceled suspend on PVOPS VM which has multi-cpu References: <5546DFD4.5070909@huawei.com> <554888E2.60908@citrix.com> In-Reply-To: <554888E2.60908@citrix.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.30.65] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2200 Lines: 55 On 2015.5.5 17:09, David Vrabel wrote: > On 04/05/15 03:56, Ouyang Zhaowei (Charles) wrote: >> The hypervisor continues assuming that vcpu_info is stored in per-cpu data which was set up by xen_vcpu_setup(), >> while on canceled suspend, the call to xen_hvm_init_shared_info() will now make the guest think that vcpu_info >> is in the shared page, so we do not call xen_hvm_init_shared_info() on suspend canceled. > > I don't understand what the impact of this fix is. Can you include this > in the commit message? > > David Sure, please let me know if there is anything not clear enough. vcpu_info would be reset to wrong place on canceled suspend on PVOPS VM which has multi-cpu The hypervisor continues assuming that vcpu_info is stored in per-cpu data which was set up by xen_vcpu_setup(), while on canceled suspend, the call to xen_hvm_init_shared_info() will make the guest think that vcpu_info is in the shared page. This will cause non-boot cpus keep checking a wrong vcpu_info address and can not handle irqs any more after suspend canceled, for example after we do "xl save -c/restore", PVOPS VM can not be resumed as the cpus can not finish their irqs. > >> Signed-off-by: Charles Ouyang >> Reviewed-by: Boris Ostrovsky >> --- >> arch/x86/xen/suspend.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c >> index d949769..b2bed45 100644 >> --- a/arch/x86/xen/suspend.c >> +++ b/arch/x86/xen/suspend.c >> @@ -32,7 +32,8 @@ static void xen_hvm_post_suspend(int suspend_cancelled) >> { >> #ifdef CONFIG_XEN_PVHVM >> int cpu; >> - xen_hvm_init_shared_info(); >> + if (!suspend_cancelled) >> + xen_hvm_init_shared_info(); >> xen_callback_vector(); >> xen_unplug_emulated_devices(); >> if (xen_feature(XENFEAT_hvm_safe_pvclock)) { >> > > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/