From: Maxim Levitsky <mlevitsk@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH] KVM: x86: disable on 32-bit unless CONFIG_BROKEN
Date: Wed, 28 Sep 2022 20:43:39 +0300 [thread overview]
Message-ID: <1d04809ca55fc667f60adf31dc6f1adff089d2c0.camel@redhat.com> (raw)
In-Reply-To: <YzRycXDnWgMDgbD7@google.com>
On Wed, 2022-09-28 at 16:12 +0000, Sean Christopherson wrote:
> On Wed, Sep 28, 2022, Paolo Bonzini wrote:
> > On 9/28/22 09:10, Maxim Levitsky wrote:
> > > I also think that outside KVM developers nobody should be using KVM on 32 bit host.
> > >
> > > However for_developement_ I think that 32 bit KVM support is very useful, as it
> > > allows to smoke test the support for 32 bit nested hypervisors, which I do once in a while,
> > > and can even probably be useful to some users (e.g running some legacy stuff in a VM,
> > > which includes a hypervisor, especially to run really legacy OSes / custom bare metal software,
> > > using an old hypervisor) - or in other words, 32 bit nested KVM is mostly useless, but
> > > other 32 bit nested hypervisors can be useful.
> > >
> > > Yes, I can always use an older 32 bit kernel in a guest with KVM support, but as long
> > > as current kernel works, it is useful to use the same kernel on host and guest.
> >
> > Yeah, I would use older 32 bit kernels just like I use RHEL4 to test PIT
> > reinjection. :) But really the ultimate solution to this would be to
> > improve kvm-unit-tests so that we can compile vmx.c and svm.c for 32-bit.
>
> Agreed. I too use 32-bit KVM to validate KVM's handling of 32-bit L1 hypervisors,
> but the maintenance cost is painfully high.
>
But is is actually? I test it routinely and it it does work quite well IMHO.
As far as my opinion goes I do volunteer to test this code more often,
and I do not want to see the 32 bit KVM support be removed *yet*.
Best regards,
Maxim Levitsky
next prev parent reply other threads:[~2022-09-28 17:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-26 16:51 [PATCH] KVM: x86: disable on 32-bit unless CONFIG_BROKEN Paolo Bonzini
2022-09-27 17:07 ` Sean Christopherson
2022-09-28 7:10 ` Maxim Levitsky
2022-09-28 9:55 ` Paolo Bonzini
2022-09-28 16:12 ` Sean Christopherson
2022-09-28 17:43 ` Maxim Levitsky [this message]
2022-09-28 17:44 ` Maxim Levitsky
2022-09-28 17:55 ` Sean Christopherson
2022-09-29 13:26 ` Paolo Bonzini
2022-09-29 13:52 ` Maxim Levitsky
2022-09-29 15:07 ` Paolo Bonzini
2023-02-17 19:36 ` Thomas Huth
2023-02-22 22:27 ` Sean Christopherson
2023-02-23 7:01 ` Thomas Huth
2023-02-23 8:33 ` Maxim Levitsky
2023-02-23 22:10 ` Sean Christopherson
2023-02-24 6:28 ` Thomas Huth
2022-09-28 10:04 ` Paolo Bonzini
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