Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755236AbbEERVa (ORCPT ); Tue, 5 May 2015 13:21:30 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:45458 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750718AbbEERV2 (ORCPT ); Tue, 5 May 2015 13:21:28 -0400 X-IronPort-AV: E=Sophos;i="5.13,373,1427760000"; d="scan'208";a="261915085" Message-ID: <5548FC15.5020909@citrix.com> Date: Tue, 5 May 2015 18:21:25 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: "Ouyang Zhaowei (Charles)" , 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> <5548C366.1000509@huawei.com> In-Reply-To: <5548C366.1000509@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2496 Lines: 64 On 05/05/15 14:19, Ouyang Zhaowei (Charles) wrote: > > > 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. Ok, so it's only cancelled suspends that are affected. Can you make the clear in the commit and resubmit. This looks like something that should be tagged for stable as well. David > >> >>> 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/