Re: [PATCH v4 0/4] arm64: cross-CPU NMI via SDEI

From: Breno Leitao

Date: Fri Jun 26 2026 - 04:48:46 EST


On Mon, Jun 22, 2026 at 09:52:40AM -0700, Doug Anderson wrote:
> Having them as a stop-gap until true NMI is available
> seems nice to me

I completely agree. Should these patches unfortunately not make it upstream,
my plan is to maintain them downstream at Meta kernels until the Meta fleet
no longer contains any non-FEAT_NMI hosts.

The trade-offs under consideration are:

1) Accept the performance overhead from pseudo-NMI
2) Lose debuggability by disabling NMI entirely
3) Maintain downstream patches

Of these three options, carrying downstream patches appears to be the least
disruptive path for our business needs.