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 [thread overview]
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.
next prev parent reply other threads:[~2019-03-18 13:30 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-17 14:36 [RFC PATCH] KVM: arm/arm64: Enable direct irqfd MSI injection 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
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