From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [BUG] Only 1 VCPU is detected in Xen 4.1 - "A valid RSDP was not found" Date: Tue, 22 Jul 2014 08:50:41 +0100 Message-ID: <53CE17D1.7080005@citrix.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: John Mok , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 22/07/2014 05:54, John Mok wrote: > Hi, > > I tried to install Xen 4.1 using new Intel Atom C2758, which has 8 > cores and VT-x feature. However, only 1 CPU was available in Dom0 and > SMP disabled. > > When booted to normal kernel 3.2 without Xen, all 8 cores were available. > > Thanks a lot. > > John Mok > > (the acpi dump is also attached) > > === Begin of xm dmesg === > > (XEN) ACPI Error (tbxfroot-0220): A valid RSDP was not found [20070126] > (XEN) System RAM: 32759MB (33545412kB) > (XEN) Domain heap initialised > (XEN) Table is not found! > (XEN) Enabling APIC mode: Flat. Using 1 I/O APICs > (XEN) SMP mptable: no processors registered! > (XEN) BIOS bug, MP table errors detected!... > (XEN) ... disabling SMP support. (tell your hw vendor) > (XEN) Found and enabled local APIC! > > === End of xm dmesg === Xen only has a single CPU because it can't find the ACPI tables, and the MP table lists no secondary processors. By default, dom0 has the same number of vcpus as Xen has pcpus. Can you post all of xm dmesg rather than just a snippet? Is this a legacy boot or an EFI boot? Are you able to try a more up-to-date version of Xen? 4.1 is quite old now. ~Andrew