From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaly Kuznetsov Subject: Re: Failure to boot HVM guest with more than 32 VCPUS Date: Thu, 13 Aug 2015 14:58:22 +0200 Message-ID: <87io8je45t.fsf@vitty.brq.redhat.com> References: <87mvxwq20c.fsf@vitty.brq.redhat.com> <874mk3fvlw.fsf@vitty.brq.redhat.com> <6C6415CE-6544-45FD-94C1-02C4C7456428@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6C6415CE-6544-45FD-94C1-02C4C7456428@oracle.com> (Konrad Rzeszutek Wilk's message of "Thu, 13 Aug 2015 07:45:41 -0400") List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk Cc: "Hao, Xudong" , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org Konrad Rzeszutek Wilk writes: > On August 13, 2015 4:20:11 AM EDT, Vitaly Kuznetsov wrote: >>"Hao, Xudong" writes: >> >>>> -----Original Message----- >>>> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com] >>>> Sent: Wednesday, August 12, 2015 5:40 PM >>>> To: Hao, Xudong >>>> Cc: xen-devel@lists.xen.org >>>> Subject: Re: [Xen-devel] Failure to boot HVM guest with more than 32 >>>> VCPUS >>>> >>>> "Hao, Xudong" writes: >>>> >>>> > Hi, >>>> > >>>> > In X86_64 platform, we noticed an issue that Xen boot a RHEL6u6 or >>>> > Fedora22 guest, when configure the VCPU more than 32, the guest >>will >>>> > fail to boot up. >>>> >>>> The issue is well-known for RHEL6.6 (and is fixed in 6.7 and in >>6.6.z) >>>> but Fedora22 should boot. The log below is from RHEL6.6, can you >>please >>>> provide one from Fedora? >>>> >>> >>> Vitaly, >>> >>> Thanks for quick response. Is the fix in guest pv driver? >> >>The fix is in RHEL6 kernel, prior to it there is no support for >>vcpu_info outside of shared_info and so only 32 vcpus are supported. > > Is the patch available somewhere? Or is it the one I had posted some time ago? > These are upstream commit ids (linux.git): c06ee78d73fd24e8d8a65f16380f6a0551107e1b "xen: support large numbers of CPUs with vcpu info placement" 90d4f5534d14815bd94c10e8ceccc57287657ecc "xen:pvhvm: enable PVHVM VCPU placement when using more than 32 CPUs." d5b17dbff83d63fb6bf35daec21c8ebfb8d695b5 "xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_info" -- Vitaly