svn commit: r209371 - in head/sys: amd64/amd64 amd64/include conf dev/acpica i386/i386 i386/include isa kern pc98/cbus sys x86/isa x86/x86

[Alexander Motin]

John Baldwin wrote:
> On Monday 21 June 2010 4:08:33 pm Alexander Motin wrote:
>> Kostik Belousov wrote:
>>> On Sun, Jun 20, 2010 at 09:33:29PM +0000, Alexander Motin wrote:
>>>> Author: mav
>>>> Date: Sun Jun 20 21:33:29 2010
>>>> New Revision: 209371
>>>> URL: http://svn.freebsd.org/changeset/base/209371
>>>>
>>>> Log:
>>>>   Implement new event timers infrastructure. It provides unified APIs for
>>>>   writing event timer drivers, for choosing best possible drivers by 
> machine
>>>>   independent code and for operating them to supply kernel with 
> hardclock(),
>>>>   statclock() and profclock() events in unified fashion on various 
> hardware.
>>> This broke QEMU for me. I cannot boot FreeBSD guest under QEMU anymore.
>>> QEMU (not FreeBSD kernel) panics with
>>> qemu: level-triggered hpet not supported
>>> message.
>> According to specification, it is not optional. No more cookies!
> 
> Why do you even need a level triggered interrupt?  The FSB interrupt is not 
> shared with anything else, so it can be edge triggered just fine.  We set all 
> MSI interrupts to edge triggered on x86.

FSB interrupts, when supported, surely work as edge-triggered. But not
all hardware support FSB interrupts. In such cases level-triggering
used, to be able to share interrupts. Without verbose dmesg I can't
imagine what QEMU supports and what exactly happened there.

-- 
Alexander Motin