Re: [PATCH v3 0/4] KVM: Speed up MMIO registrations

[Sean Christopherson <seanjc@google.com>]

On Tue, Aug 19, 2025, Keir Fraser wrote:
> This is version 3 of the patches I previously posted here:
> 
>  https://lore.kernel.org/all/20250716110737.2513665-1-keirf@google.com/
> 
> Changes since v2:
> 
>  * Rebased to v6.17-rc2

Note, looks like you missed a tested tag from Li on patch 4:

https://lkml.kernel.org/r/b778c98abb4b425186bfeb1f9bed0c7a%40baidu.com

Nits aside, this looks good to my eyes (though I haven't tested yet).

Marc/Oliver,

Can you weigh in on the vgic changes when you get a chance?  And a more expert
set of eyeballs on the memory ordering side of things would be nice to have, too :-)

As for landing this, I'd be happy to take this through a dedicated kvm-x86 topic
branch, or I can provide an ack on patches 3 and 4 (there's basically zero chance
of this causing a conflict in x86).

> Keir Fraser (4):
>   KVM: arm64: vgic-init: Remove vgic_ready() macro
>   KVM: arm64: vgic: Explicitly implement vgic_dist::ready ordering
>   KVM: Implement barriers before accessing kvm->buses[] on SRCU read
>     paths
>   KVM: Avoid synchronize_srcu() in kvm_io_bus_register_dev()
> 
>  arch/arm64/kvm/vgic/vgic-init.c | 14 +++--------
>  arch/x86/kvm/vmx/vmx.c          |  7 ++++++
>  include/kvm/arm_vgic.h          |  1 -
>  include/linux/kvm_host.h        | 11 ++++++---
>  virt/kvm/kvm_main.c             | 43 +++++++++++++++++++++++++++------
>  5 files changed, 53 insertions(+), 23 deletions(-)
> 
> -- 
> 2.51.0.rc1.193.gad69d77794-goog
>