[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Problem with QEMU on KVM

From: Gerhard Wiesinger
Subject: Re: [Qemu-devel] Problem with QEMU on KVM
Date: Tue, 13 Apr 2010 21:38:55 +0200 (CEST)
User-agent: Alpine 2.00 (LFD 1167 2008-08-23)

On Mon, 12 Apr 2010, Jamie Lokier wrote:

Mulyadi Santosa wrote:
Hi Gerhard...

On Sun, Apr 11, 2010 at 20:52, Gerhard Wiesinger <address@hidden> wrote:
OK, uses the following ports:
Port 0x20: 8259 interrupt controller
Port 0x40: 8253 timer

Interrupt 0x1A:
ah=0x00: fetches system timer counters
ah=0x02: reads the clock
ah=0x04: fetches date

So there must be something wrong with KVM with the above functionality (I
guess the timers).

Hmm, my silly guess is, maybe the timer is seen as decremented....or
at least "stuck".

I have very little knowledge about git, but maybe you can start doing
git bisect to narrow which git commit that introduce such behaviour.
Meanwhile, let's wait for comments from one of the KVM developers.

There are various -no-kvm-XXX options to try:

-no-kvm-irqchip disable KVM kernel mode PIC/IOAPIC/LAPIC
-no-kvm-pit     disable KVM kernel mode PIT
-no-kvm-pit-reinjection disable KVM kernel mode PIT interrupt reinjection

Any of them might be causing this problem.

They disable in-kernel emulation of the interrupt controller and timer
chips, and force the qemu version to be used.  It's possible the
in-kernel emulation is buggier than the qemu version.

Hello Jamie, thanx so far.

I'm starting in this way:
/root/download/qemu/qemu-0.12.3/x86_64-softmmu/qemu-system-x86_64 -enable-kvm 

All options you mentioned don't work:
/root/download/qemu/qemu-0.12.3/x86_64-softmmu/qemu-system-x86_64: invalid 
option -- '-no-kvm-irqchip'
/root/download/qemu/qemu-0.12.3/x86_64-softmmu/qemu-system-x86_64: invalid 
option -- '-no-kvm-pit'
/root/download/qemu/qemu-0.12.3/x86_64-softmmu/qemu-system-x86_64: invalid 
option -- '-no-kvm-no-kvm-irqchip'

Is there another way of startup or is it working only on newer versions?

BTW: For me it is very unclear what's the difference between the following commands:
qemu -enable-kvm

How can I build the kvm executable? Different source tree? Newer version from branch?

Maybe someone can explain the different versions of qemu/kvm and branches etc. and possible features in detail.




reply via email to

[Prev in Thread] Current Thread [Next in Thread]