[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option
From: |
Jan Kiszka |
Subject: |
[Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option |
Date: |
Mon, 24 May 2010 18:20:15 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
Juan Quintela wrote:
> Jan Kiszka <address@hidden> wrote:
>> Juan Quintela wrote:
>
>> Unless this is deadly urgent, please hold it back until we sorted out
>> some more fundamental issues with the HPET, specifically ported it to qdev.
>
> This series are independent of the qdev change (it almost don't change
> hpet code at all). It is basically independent of almost everything else.
It causes mechanical breakage to the qdev change (and the one I'm
hacking on ATM).
>
>> But I'm also not convinced about the general approach. Except for RHEL
>> packagers, no one seems to gain any benefit from having CONFIG_HPET.
>
> This happens to us all the time for lots of devices. And the big
> problem is that there is no sane way to disable them :(
>
> If we can agree in a mechanism to disable them (like this one) or
> something similar, we could remove it.
>
> Our biggest problem with shipping a device is that we are going to
> support it for 7 years, you can guess why we want to be conservative.
In this particular case, it is a one line patch: "no_hpet = 1;", hardwired.
>
>> The
>> HPET model is still incomplete in has some remaining quicks (hold on for
>> improvements), but that doesn't qualify it for !CONFIG_HPET,
>> specifically as it is deeply hooked into every modern PC. If I was
>> asked, I guess I would nack this switch.
>
> Then, what should we do?
Help fixing it (e.g. testers will soon be welcome).
> We already have to disable hpet for 5.4 (1 year ago). It was done with
> a local hack because it was supposed that for next big release it would
> have been fixed.
But this remains a RHEL issue. Redhat decided to compile out features
that are unsupported, others seem to handle this differently.
>
> Here we are, and device is still not fixed, what to do? Another local
> patch? Just get upstream to integrate a sane way to disable it and let
> in enable by default?
Let's start with listing your requirements to no longer disable HPET.
That would already help us to asses how long !CONFIG_HPET would actually
be of any use at all. I'm yet optimistic that we can resolve most if not
all remaining concerns for 0.13 - and CONFIG_HPET would at best be 0.13
material anyway.
>
> Notice that this patch was sent against hpet as one example, if we agree
> that this "way" of disabling devices is ok, we could disable more
> devices/have more flexibility. Notice that in general, we (RHEL/KVM)
> are interested in a small subset of qemu devices.
At least HPET is IMHO a bad example as it is, just like e.g. the IOAPIC,
an essential part of today's x86 systems.
Jan
signature.asc
Description: OpenPGP digital signature
- [Qemu-devel] [PATCH 0/6] Make hpet a compile time option, Juan Quintela, 2010/05/24
- [Qemu-devel] [PATCH 1/6] Create again config-device.h and config.devices.h, Juan Quintela, 2010/05/24
- [Qemu-devel] [PATCH 2/6] Move no_hpet declaration to hpet_emul.h, Juan Quintela, 2010/05/24
- [Qemu-devel] [PATCH 3/6] Move no_hpet test to inside hpet_init(), Juan Quintela, 2010/05/24
- [Qemu-devel] [PATCH 6/6] Create CONFIG_HPET, Juan Quintela, 2010/05/24
- [Qemu-devel] [PATCH 4/6] Make hpet_in_legacy_mode() return 0 for !TARGET_I386, Juan Quintela, 2010/05/24
- [Qemu-devel] [PATCH 5/6] make hpet_in_legacy_mode() return a bool, Juan Quintela, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Juan Quintela, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Jan Kiszka, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Paul Brook, 2010/05/24
- Re: [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Anthony Liguori, 2010/05/24
- Re: [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Paul Brook, 2010/05/24
- Re: [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Anthony Liguori, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Juan Quintela, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Anthony Liguori, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Jan Kiszka, 2010/05/24
- [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option, Blue Swirl, 2010/05/24