Messages in this thread | | | Date | Mon, 18 Mar 2019 13:30:40 +0000 | From | Marc Zyngier <> | Subject | Re: [RFC PATCH] KVM: arm/arm64: Enable direct irqfd MSI injection |
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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.
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