[PATCH v4 0/4] KVM: arm64: Fix underallocation of storage for SVE state

Marc Zyngier maz at kernel.org
Fri Jul 5 06:20:05 PDT 2024


On Thu, 04 Jul 2024 18:28:15 +0100,
Mark Brown <broonie at kernel.org> wrote:
> 
> As observed during review the pKVM support for saving host SVE state is
> broken if an asymmetric system has VLs larger than the maximum shared
> VL, fix this by discovering then using the maximum VL for allocations
> and using RDVL during the save/restore process.

I really don't see why we need such complexity here.

Fuad did post something[1] that did the trick with a far less invasive
change, and it really feels like we are putting the complexity at the
wrong place.

So what's wrong with that approach? I get that you want to shout about
secondary CPUs, but that's an orthogonal problem.

	M.

[1] https://lore.kernel.org/r/20240606092623.2236172-1-tabba@google.com

-- 
Without deviation from the norm, progress is not possible.



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