From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: Re: [PATCH] KVM: arm64: vgic: Allocate private interrupts on demand
Date: Thu, 2 May 2024 10:02:30 -0700 [thread overview]
Message-ID: <ZjPHJjSJMe2BgaXr@linux.dev> (raw)
In-Reply-To: <20240502154545.3012089-1-maz@kernel.org>
On Thu, May 02, 2024 at 04:45:45PM +0100, Marc Zyngier wrote:
> Private interrupts are currently part of the CPU interface structure
> that is part of each and every vcpu we create.
>
> Currently, we have 32 of them per vcpu, resulting in a per-vcpu array
> that is just shy of 4kB. On its own, that's no big deal, but it gets
> in the way of other things:
>
> - each vcpu gets mapped at EL2 on nVHE/hVHE configurations. This
> requires memory that is physically contiguous. However, the EL2
> code has no purpose looking that the interrupt structures and
typo: looking at the interrupt ...
> could do without them being mapped.
>
> - supporting features such as EPPIs, which extend the number of
> privrate interrupts past the 32 limit would make the array
typo: private
> even larger, even for VMs that do not use the EPPI feature.
>
> Address these issues by moving the private interrupt array outside
> of the vcpu, and replace it with a simple pointer. We take this
> opportunity to make it obvious what gets initialised when, as
> that path was remarkably opaque, and tighten the locking.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
--
Thanks,
Oliver
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-05-02 17:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-02 15:45 [PATCH] KVM: arm64: vgic: Allocate private interrupts on demand Marc Zyngier
2024-05-02 17:02 ` Oliver Upton [this message]
2024-05-03 13:35 ` Marc Zyngier
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=ZjPHJjSJMe2BgaXr@linux.dev \
--to=oliver.upton@linux.dev \
--cc=james.morse@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
--cc=yuzenghui@huawei.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).