Messages in this thread |  | | Date | Fri, 12 Jan 2018 20:03:49 -0200 | From | Henrique de Moraes Holschuh <> | Subject | Re: Improve retpoline for Skylake |
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On Fri, 12 Jan 2018, Andi Kleen wrote: > > Skylake still loses if it takes an SMI, right? > > SMMs are usually rare, especially on servers, and are usually > not very predictible, and even if you have
FWIW, a data point: SMIs can be generated on demand by userspace on thinkpad laptops, but they will be triggered from within a kernel context. I very much doubt this is a rare pattern...
However, since in this vendor-firmware-nastyness pattern the SMIs are fired off from inside the kernel (inside the ACPI subsystem), it would be covered by the mitigations done when entering the kernel from syscalls and hardware interrupts. Hopefully.
-- Henrique Holschuh
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