LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Marc Zyngier <marc.zyngier@arm.com>
To: Zenghui Yu <yuzenghui@huawei.com>
Cc: <christoffer.dall@arm.com>, <eric.auger@redhat.com>,
	<andre.przywara@arm.com>, <james.morse@arm.com>,
	<julien.thierry@arm.com>, <suzuki.poulose@arm.com>,
	<kvmarm@lists.cs.columbia.edu>, <mst@redhat.com>,
	<pbonzini@redhat.com>, <rkrcmar@redhat.com>,
	<kvm@vger.kernel.org>, <wanghaibin.wang@huawei.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	"Raslan, KarimAllah" <karahmed@amazon.de>
Subject: Re: [RFC PATCH] KVM: arm/arm64: Enable direct irqfd MSI injection
Date: Mon, 18 Mar 2019 13:30:40 +0000
Message-ID: <20190318133040.1cfad9a4@why.wild-wind.fr.eu.org> (raw)
In-Reply-To: <86o969z42z.wl-marc.zyngier@arm.com>

On Sun, 17 Mar 2019 19:35:48 +0000
Marc Zyngier <marc.zyngier@arm.com> wrote:

[...]

> A first approach would be to keep a small cache of the last few
> successful translations for this ITS, cache that could be looked-up by
> holding a spinlock instead. A hit in this cache could directly be
> injected. Any command that invalidates or changes anything (DISCARD,
> INV, INVALL, MAPC with V=0, MAPD with V=0, MOVALL, MOVI) should nuke
> the cache altogether.

And to explain what I meant with this, I've pushed a branch[1] with a
basic prototype. It is good enough to get a VM to boot, but I wouldn't
trust it for anything serious just yet.

If anyone feels like giving it a go and check whether it has any
benefit performance wise, please do so.

Thanks,

	M.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=kvm-arm64/its-translation-cache
-- 
Without deviation from the norm, progress is not possible.

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-17 14:36 Zenghui Yu
2019-03-17 14:50 ` Raslan, KarimAllah
2019-03-17 18:05   ` Auger Eric
2019-03-17 19:35 ` Marc Zyngier
2019-03-18 13:30   ` Marc Zyngier [this message]
2019-05-15 16:38     ` Andre Przywara
2019-05-16  7:21       ` Marc Zyngier
2019-05-20 15:31         ` Zenghui Yu
2019-05-20 18:00           ` Raslan, KarimAllah
2019-03-19  1:09   ` Zenghui Yu
2019-03-19 10:01     ` Marc Zyngier
2019-03-19 15:59       ` Zenghui Yu
2019-03-19 16:57         ` Marc Zyngier

Reply instructions:

You may reply publically 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=20190318133040.1cfad9a4@why.wild-wind.fr.eu.org \
    --to=marc.zyngier@arm.com \
    --cc=andre.przywara@arm.com \
    --cc=christoffer.dall@arm.com \
    --cc=eric.auger@redhat.com \
    --cc=james.morse@arm.com \
    --cc=julien.thierry@arm.com \
    --cc=karahmed@amazon.de \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mst@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=rkrcmar@redhat.com \
    --cc=suzuki.poulose@arm.com \
    --cc=wanghaibin.wang@huawei.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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git