From: Sean Christopherson <seanjc@google.com>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: Juergen Gross <jgross@suse.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Marc Zyngier <maz@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH] KVM: move struct kvm_vcpu * array to the bottom of struct kvm
Date: Mon, 8 Nov 2021 15:35:11 +0000 [thread overview]
Message-ID: <YYlDr2HLI/eULoDy@google.com> (raw)
In-Reply-To: <1636158401.g3t5cp0jke.astroid@bobo.none>
On Sat, Nov 06, 2021, Nicholas Piggin wrote:
> Excerpts from Sean Christopherson's message of November 6, 2021 12:49 am:
> >> It would next be possible to now make this a dynamically sized array,
> >> and make the KVM_MAX_VCPUS more dynamic
> >
> > Marc has a mostly-baked series to use an xarray[1][2] that AFAICT would be well
> > received. That has my vote, assuming it can get into 5.16. Marc or Juergen,
> > are either of you actively working on that?
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=kvm-arm64/vcpu-xarray
> > [2] https://lkml.kernel.org/r/871r65wwk7.wl-maz@kernel.org
>
> Seems like a good idea if it can allow vcpu structs to be allocated to
> preferred nodes.
>
> >> however x86 kvm_svm uses its own scheme rather than kvm_arch for some reason.
> >
> > What's the problem in kvm_svm?
>
> It embeds a struct kvm so it couldn't be variable sized.
Oooh, when you said "dynamically sized" I thought you meant
struct kvm_vcpu *vcpus;
...
kvm->vcpus = kcalloc(...);
Anyways, SVM and VMX are quite different despited both being x86, to keep them
separated without requiring an extra allocation, kvm_svm and kvm_vmx embed kvm.
Ditto for vcpu_vmx and vmx_svm. Obviously not a hard requirement, but there also
hasn't been a reason not to do embed kvm/kvm_vcpu.
prev parent reply other threads:[~2021-11-08 15:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-05 3:49 [PATCH] KVM: move struct kvm_vcpu * array to the bottom of struct kvm Nicholas Piggin
2021-11-05 14:49 ` Sean Christopherson
2021-11-05 18:37 ` Marc Zyngier
2021-11-06 0:29 ` Nicholas Piggin
2021-11-08 15:35 ` Sean Christopherson [this message]
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=YYlDr2HLI/eULoDy@google.com \
--to=seanjc@google.com \
--cc=jgross@suse.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=npiggin@gmail.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).