Re: [Qemu-devel] CentOS 5.x intermittently fails to boot on QEMU 1.7.0

2014-02-22 Thread Paolo Bonzini
Il 22/02/2014 01:57, Matt Lupfer ha scritto: Thanks for the response. The hpet_timer() callback calls timer_mod() every 1 ms. That timerlist has no notify callback so it in turn calls qemu_notify_event(). The guest kernel is only enabling the HPET timer and looking for timer interrupts. FWIW

Re: [Qemu-devel] CentOS 5.x intermittently fails to boot on QEMU 1.7.0

2014-02-22 Thread Alex Bligh
On 22 Feb 2014, at 00:57, Matt Lupfer wrote: > I did some more debugging and found the problem was elsewhere. This > different timer behavior is exposing a bug in the HPET implementation. > > It's possible for the QEMU timer underlying the HPET to call the hpet_timer() > callback between when t

Re: [Qemu-devel] CentOS 5.x intermittently fails to boot on QEMU 1.7.0

2014-02-21 Thread Matt Lupfer
On 02/21/2014 06:27 AM, Alex Bligh wrote: > > On 21 Feb 2014, at 04:34, Matt Lupfer wrote: > >> >> This doesn't appear to be a solution, because with the timer rewrite, QEMU >> moves its periodic (1 ms) qemu_notify_event() call to break out of >> the main event loop from a SIGALRM handler to the r

Re: [Qemu-devel] CentOS 5.x intermittently fails to boot on QEMU 1.7.0

2014-02-21 Thread Alex Bligh
On 21 Feb 2014, at 04:34, Matt Lupfer wrote: > A git bisect points to this commit as the culprit: > > b1bbfe7 aio / timers: On timer modification, qemu_notify or aio_notify > > which was part of the Aug 2013 timer rewrite. Reverting this hunk in > particular makes the issue go away: > > > @@

Re: [Qemu-devel] CentOS 5.x intermittently fails to boot on QEMU 1.7.0

2014-02-20 Thread Paolo Bonzini
Il 21/02/2014 05:34, Matt Lupfer ha scritto: This doesn't appear to be a solution, because with the timer rewrite, QEMU moves its periodic (1 ms) qemu_notify_event() call to break out of the main event loop from a SIGALRM handler to the rearm of a QEMU timer. Presumably QEMU is counting on these

[Qemu-devel] CentOS 5.x intermittently fails to boot on QEMU 1.7.0

2014-02-20 Thread Matt Lupfer
Hello, After upgrading to QEMU 1.7.0, CentOS 5.x guests often fail to boot with the following kernel apic=debug output: > ACPI: Core revision 20060707 > enabled ExtINT on CPU#0 > ENABLING IO-APIC IRQs > ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1 > ..MP-BIOS bug: 8254 timer not connecte