From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Maxim Levitsky <mlevitsk@redhat.com>,
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 16:12:33 +0000 [thread overview]
Message-ID: <YzRycXDnWgMDgbD7@google.com> (raw)
In-Reply-To: <15291c3f-d55c-a206-9261-253a1a33dce1@redhat.com>
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.
next prev parent reply other threads:[~2022-09-28 16:12 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 [this message]
2022-09-28 17:43 ` Maxim Levitsky
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YzRycXDnWgMDgbD7@google.com \
--to=seanjc@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mlevitsk@redhat.com \
--cc=pbonzini@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).