From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49398) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1biN-0007cx-UN for qemu-devel@nongnu.org; Mon, 09 Oct 2017 13:19:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1biH-0000eh-Tl for qemu-devel@nongnu.org; Mon, 09 Oct 2017 13:19:39 -0400 Received: from 8.mo4.mail-out.ovh.net ([188.165.33.112]:59035) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e1biH-0000bh-Ms for qemu-devel@nongnu.org; Mon, 09 Oct 2017 13:19:33 -0400 Received: from player772.ha.ovh.net (b6.ovh.net [213.186.33.56]) by mo4.mail-out.ovh.net (Postfix) with ESMTP id B386DD530D for ; Mon, 9 Oct 2017 19:19:25 +0200 (CEST) Date: Mon, 9 Oct 2017 19:19:15 +0200 From: Greg Kurz Message-ID: <20171009191915.6bd2bc69@bahia.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] i386/kvm: QEMU crash when doing 'info cpus' after CPU hotplug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Eduardo Habkost , Igor Mammedov Hi x86 folks, While trying to reproduce on x86 an issue we're currently hitting on ppc, I got this: $ ./x86_64-softmmu/qemu-system-x86_64 -snapshot -no-shutdown -nographic -machine q35,accel=kvm -smp 1,maxcpus=2 -serial mon:stdio -drive file=$HOME/images/fedora26-x86_64.qcow2,if=virtio QEMU 2.10.50 monitor - type 'help' for more information (qemu) device_add host-x86_64-cpu,socket-id=1,core-id=0,thread-id=0,id=foo (qemu) info cpus error: failed to get MSR 0x38d qemu-system-x86_64: /home/greg/Work/qemu/qemu-devel/target/i386/kvm.c:2121: kvm_get_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed. Aborted (core dumped) Same happens with a pc machine. But it doesn't happen if I use cpu-add instead of device_add: (qemu) cpu-add 1 (qemu) [ 8.335221] CPU1 has been hot-added (qemu) info cpus * CPU #0: pc=0xffffffffb08986e6 (halted) thread_id=23964 CPU #1: pc=0x00000000fffffff0 thread_id=24001 This is with the QEMU master branch SHA1 530049bc1dcc24c. Cheers, -- Greg