Re: [PATCH 1/2] KVM: arm64: Introduce KVM_PGTABLE_S2_NOFWB Stage-2 flag
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From: Quentin Perret <hidden>
Date: 2021-03-17 14:48:29
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On Wednesday 17 Mar 2021 at 14:41:31 (+0000), Marc Zyngier wrote:
Hi Quentin, On Wed, 17 Mar 2021 14:17:13 +0000, Quentin Perret [off-list ref] wrote:quoted
In order to further configure stage-2 page-tables, pass flags to the init function using a new enum. The first of these flags allows to disable FWB even if the hardware supports it as we will need to do so for the host stage-2. Signed-off-by: Quentin Perret <redacted> --- One question is, do we want to use stage2_has_fwb() everywhere, including guest-specific paths (e.g. kvm_arch_prepare_memory_region(), ...) ? That'd make this patch more intrusive, but would make the whole codebase work with FWB enabled on a guest by guest basis. I don't see us use that anytime soon (other than maybe debug of some sort?) but it'd be good to have an agreement.I'm not sure how useful that would be. We fought long and hard to get FWB, and I can't see a good reason to disable it for guests unless the HW was buggy (but in which case that'd be for everyone). I'd rather keep the changes small for now (this whole series is invasive enough!).
OK, that works for me.
As for this patch, I only have a few cosmetic comments:
Happy with the suggestions, I'll fold that in v6. Cheers, Quentin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel