From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: FreeBSD boot hangs on qemu-kvm on AMD host Date: Wed, 09 Mar 2011 15:06:28 +0300 Message-ID: <4D776D44.9080302@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Dominik Klein To: KVM list Return-path: Received: from isrv.corpit.ru ([86.62.121.231]:49860 "EHLO isrv.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932113Ab1CIMGc (ORCPT ); Wed, 9 Mar 2011 07:06:32 -0500 Sender: kvm-owner@vger.kernel.org List-ID: Hello. Dominik Klein (Cc'd) reported on irc that current FreeBSD release hangs at boot in qemu-kvm. It is trivially verifiable by d/loading the bootonly FreeBSD 8.2 CD image from ftp.freebsd.org and running kvm -cdrom FreeBSD-8.2-RELEASE-amd64-bootonly.iso. The guest unpacks kernel, draws a menu (apparently in real kernel already, not in the boot loader) and starts a 10-second countdown. At this point it just stops (either at 10 or 9, ie, right at the beginning of the cycle) and kvm process starts using 100% of the CPU core given to it. With this typical kvm_stats from qemu-kvm 0.14: kvm statistics exits 43397783 1400960 halt_exits 42862622 1400769 irq_exits 5487 172 host_state_reload 300074 101 io_exits 292212 18 irq_injections 768 18 halt_wakeup 257 3 mmu_pte_write 7702163 0 insn_emulation 378273 0 mmio_exits 15786 0 pf_fixed 4817 0 mmu_shadow_zapped 170 0 mmu_cache_miss 151 0 remote_tlb_flush 2 0 signal_exits 1 0 fpu_reload 1 0 I tried i386 and amd64 guest images, and tried the same thing with qemu-kvm 0.12.5 and 0.14.0 - the effect is exactly the same. So far the 3 affected systems where we tried this are all AMD machines. My home box is AthlonII, my work box is PhenomI 9750, and Dominik tries it on Opteron 6174. Running it with -no-kvm lets the guest to go (but obviously very slow). Using -no-kvm-irqchip helps too. Any guess what it can be? Thanks! /mjt